Chimney Problems – CheckThisHouse https://www.checkthishouse.com Home maintenance, remodeling, repair, and improvement tips for your property Sat, 06 Mar 2021 20:54:04 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.16 3 Ways To Know Your Chimney Needs Cleaning https://www.checkthishouse.com/8299/3-ways-to-know-your-chimney-needs-cleaning.html Sat, 13 Oct 2018 18:16:10 +0000 https://www.checkthishouse.com/?p=8299 We all love the coziness that comes from a real wood burning stove or fireplace, as opposed to the sufficient yet lackluster heat that comes from a furnace – especially during the long, cold winters we are so accustomed to. But with the added luxury of having a real wood fire to keep us warm, ... Read more]]>

We all love the coziness that comes from a real wood burning stove or fireplace, as opposed to the sufficient yet lackluster heat that comes from a furnace – especially during the long, cold winters we are so accustomed to. But with the added luxury of having a real wood fire to keep us warm, there are also added responsibilities.

One important consideration to keep in mind when using your fireplace is properly maintaining your chimney. Of course, we can’t see our chimneys, so they often fall into the “out of sight, out of mind” list of household chores – but that needs to change.

Keep reading below to learn not only why keeping your chimney clean is so important, but also the 3 main indicators that tell you your chimney needs cleaning.

Why Does Your Chimney Need To Be Cleaned?

The consequences that can arise from dirty or damaged chimney flues can simply be inconvenient or expensive, but they can go so far as to be fatal – which, we think, is not a risk worth taking.

On the minor end of things, a dirty chimney can lead to a variety of problems with functionality that may require repairs. Having to get repairs done is not only a hassle, especially if the cold weather has already begun, but can be costly.

Additionally, even if no repairs are needed, a dirty chimney also lowers the energy efficiency of your fireplace or woodstove – again, not something you want when the cold weather is just around the corner.

On the more concerning end of things, a dirty chimney can actually be a serious hazard and pose real risk to your home and the safety of your family – did you know that there are over 25,000 chimney fires in the US every year?

The scary thing about chimney fires is that they can often burn for a long time, going undetected by homeowners until it is too late. Some things to take note of that can indicate a chimney fire are loud cracking or popping noises as well as dense, dark smoke.

As you can see, there are sufficient reasons as to why you should take the cleanliness of your chimney seriously.

How To Know When It’s Time

Now that you understand why it’s important to maintain a clean chimney, you are probably wondering things like “how often should it be cleaned?” or “how do I know if it’s ready to be cleaned or not?”

And, of course, there is no definitive answer to these questions. Every chimney is different. (Cliché, we know).

But seriously – we can’t honestly tell you that you need to clean your chimney once per year or after you’ve used the fireplace “x” amount of times. How quickly creosote (the chemical buildup that signals a “dirty” chimney) depends, really, on factors such as how you use the fireplace, what type of wood you are burning, and how the wood burns (aka how good you are at making a proper fire…).

Checking for Creosote

The only real way to know when it’s time for a good chimney sweep is to check the current cleanliness of the chimney with your own two eyes (or hire someone to do it, but it’s easy enough to do yourself).

  • Step 1: put on goggles, a dust mask, and grab your handy, dandy flashlight.
  • Step 2: make sure there is no downdraft coming through the chimney.
  • Step 3: use the fire poker and scratch the black surface above the fireplaces’ damper/smoke chamber.

If the scratch in the black layer (which is the creosote build up) is paper thin, you are in the safe zone – your chimney is not yet in need of a cleaning.

If the scratch appears to be around 1/8th of an inch thick, you may have a bit of leeway, but should definitely schedule a cleaning for the near future.

If the scratch is nearing or over ¼ of an inch thick, you have fully entered the danger zone – schedule a cleaning now and don’t use the fireplace until after the chimney is clean again. With this much buildup, a chimney fire could happen too easily at any moment.

Get Checkin’!

It’s not hard to do and it could save time, money, and even lives. Put on your goggles and check your chimney today. If it doesn’t need to be cleaned, you are in the clear and can continue on enjoying some cozy fire lit evenings. If it does, simply call your local chimney sweet company and they would be happy to bring your chimney back to a safe state!

References

  1. https://www.checkthishouse.com/72/chimney-flue-furnace-water-heater-venting.html
  2. https://www.familyhandyman.com/cleaning/when-to-clean-a-chimney-flue/view-all/
]]>
Keep Your House Warm This Fall Without Breaking the Bank https://www.checkthishouse.com/8283/keep-your-house-warm-this-fall-without-breaking-the-bank.html Mon, 17 Sep 2018 15:00:21 +0000 https://www.checkthishouse.com/?p=8283 According to the U.S. Department of Energy half of what Americans spend on energy goes towards heating and cooling their homes, which means it is the single costliest energy expense for most families. The majority of us — and especially those who live in northern regions of the country — know that fall and winter ... Read more]]>

According to the U.S. Department of Energy half of what Americans spend on energy goes towards heating and cooling their homes, which means it is the single costliest energy expense for most families.

The majority of us — and especially those who live in northern regions of the country — know that fall and winter can take a heavy toll on the budget as we rely on our homes to keep us warm and shield us from the elements.

But there is smart, preventative home maintenance that can be done in effort to ensure your family stays warm without breaking the budget.

 

Inspect Your Furnace

The most important thing you can do to protect your budget from unnecessary heating costs is ensure that your furnace is in good working order. A furnace that isn’t is a furnace that is working inefficiently and potentially even dangerously.

Hire a Professional

Hiring a professional to inspect your furnace is the best way to ensure your home is prepared for fall and winter. Professionals bring with them the training and experience required for the most thorough of inspections.

According to real estate expert Patrick Chism, “Even if you have a new home, no construction is entirely without fault. Whether the issues are big or small, having an inspection done will open your eyes to potential problems.”

It’s valuable to recognize that even if nothing appears to be wrong, it could be, and having the right set of eyes may be the solution to the problem you don’t even know you have.

Do-It-Yourself

There’s a chance that even if you aren’t a professional, you do have experience with heat systems. Additionally, conducting routine maintenance yourself is a way to save even more funds.

If you’re going to inspect the furnace yourself, here are some key things to remember about when you should bring in a professional in the name of safety:

Be careful: Always turn off the source of power. Hit the off switch on electrical furnaces and turn off the gas line on gas furnaces.

Check flames: Whatever type of furnace you have, it should produce steady blue flames. A yellow flame means there is something contaminating the flame, and you need to call a pro.

Smell: While an occasional, small whiff of gas isn’t likely cause for concern, a large amount or regular occurance is a sign of a leak that needs immediate attention.

Listen: If a noise seems out of place, or a vibration is questionable, these are also signs that you need to call a professional.

However you decide to go about inspecting your furnace at the beginning of the chilly season, remember to prioritize safety. Even if you have a thorough how-to guide, if you’re uncomfortable, don’t hesitate to bring someone in who can put your mind at ease; it will be money well spent, especially in light of how much you’ll likely save on utility bills.

 

Ensure Your Home Isn’t Releasing Heat

The best heat source in the world cannot combat a home that has trouble keeping the warm air produced inside. Thus, it’s worthwhile to take the time before the cold hits to make sure that the usual heat-releasing suspects aren’t causing you to use your heater more than absolutely necessary.

When The Washington Post overviewed the major ways heat escapes homes these were the most substantial problem areas:

Ceilings, walls, and floors: Even well-insulated houses inevitably have gaps and holes that permit heat to escape in these areas. Heated areas that have openings into unheated areas are surefire ways to lose the heat you’re paying for.

Good solutions include insulating the backs of areas like attic doors and hatches, and weather-stripping their edges. Additionally, small hacks like covering your hardwood or tile floors can add a layer insulation.

Ducts and plumbing penetrations: Holes that allow pipes, vents, and ducts to pass through walls often have extra space that allows heated air to escape. A caulk or foam spray is a smart and relatively easy way to seal them.

Fireplace: Fireplace maintenance experts recommend checking the chimney a minimum of once a year to ensure there are no cracks, which would obviously lead to heat loss. Additionally, if you have a fireplace with a poorly fitted or missing damper, that fireplace is allowing air to pass through. If you close the flue, light a flame, and the smoke travels upwards into the chimney you have a leak.

Windows and doors: Depending on the size of the gaps surrounding your windows and doors, there is the potential for major heat loss in these areas. Utilizing weather stripping and indoor caulk can make a drastic difference.

Many of the common ways our homes lose heat can be treated fairly easily after a quick trip to the hardware store. And what’s more, these fixes will pay for themselves as you reap the rewards of a well-insulated home. Fall is the season we love best, but a skyrocketing energy or gas bill can easily distract from the pleasure of it. The good news is that with a relatively modest amount of planning, your preventative home maintenance efforts can keep your space warm throughout the entire season, without draining all of your financial resources.

]]>
Furnace, Water Heater & Vent Pipe Clearance Guides & Locations https://www.checkthishouse.com/3151/furnace-water-heater-vent-pipe-clearances-and-locations.html Sat, 07 Mar 2009 03:25:02 +0000 http://checkthishouse.com/?p=3151 furnace, hot water tank clearance locationsGas burning appliances vent pipes produce heat when discharging exhaust gases to exterior. Temperature of the vent pipe is transferred to the surrounding area and all the materials that are in the vent pipe vicinity. Problems start arising if those materials are combustible and located to close to the furnace, water heater vent pipe. If you apply heat to a combustible material for some period of time (that varies between materials), its point of ignition will gradually get lower and eventually little heat will be required to start a fire – that’s why you need a clearance between the vent pipe and a combustible material.]]> furnace, hot water tank clearance locations

Vent pipe clearance to combustible materials

Visit water heater inspection for more information about this subject.

Vent pipe clearances - single wall vent pipe not permitted in attic, too close to framing - 6 inches minimum distance to combustiblesFurnace, water heater vent pipe clearance - paper and wood framing are highly flammable and require 6 inch clearance to a single wall vent pipeFurnace and water heater vent pipes require clearance to combustible materials – why is that necessary?

Gas burning appliances vent pipes produce heat when discharging exhaust gases to exterior.

Temperature of the vent pipe is transferred to the surrounding area and all the materials that are in the vent pipe vicinity. Problems start arising if those materials are combustible and located to close to the furnace, water heater vent pipe.

Furnace, water heater vent pipe clearances - single wall vent pipe installed too close to the main beamIf you apply heat to a combustible material for some period of time (that varies between materials), its point of ignition will gradually get lower and eventually little heat will be required to start a fire – that’s why you need a clearance between the vent pipe and a combustible material.

Flash point / temperature at which wood will ignite is 572F (300C).

For all of us not aware of this condition, here are the required / minimum furnace, water heater vent pipe clearances and locations where the single or double wall vent pipes can be installed.

Furnace / water heater vent pipe clearance – single wall

Furnace, water heater vent pipe clearances - single wall vent pipe requires 6 inches clearance from the floor framing

Minimum distance between the single wall vent pipe and combustible materials is 6”

The minimum distance between the single wall vent pipe and combustible materials is 6”

The single wall vent pipe cannot be concealed inside the wall or floor. Even if you keep the clearances at the entrance and exit from that space, whatever section is inside must be double wall type pipe.

A vent pipe is an important part of the gas water heater maintenance – don’t forget your schedule.Furnace, water heater vent pipe clearances - single wall cannot penetrate ceiling, wall or floorFurnace, water heater vent pipe clearances - no single wall can enter ceiling, wall or floorThe reasoning is simple – you can’t see what is happening inside the wall or floor, and if the single wall vent pipe starts corroding, separates, leaks exhaust gases, you’ll have no control over it. Also, concealed spaces have no way of discharging heat and 6” vent pipe clearance simply wouldn’t help.

Furnace, water heater vent pipe clearance - single wall vent pipe is not permitted in unconditioned atticFurnace, water heater vent pipe clearances - no single wall furnace vent pipe is permitted in an unconditioned attic The furnace, water heater single wall vent pipe cannot start in or pass through the attic. Also, it cannot be used in the crawlspace or other unconditioned space. The exceptions are unconditioned basements and garages within the exterior walls if local 99% winter design temperature equals or is larger than 5F.

Winter design temperature is the temperature that is exceeded during either 99% or 97.5% of the hours in December, January and February. Heating systems through the US are designed / calculated based on winter design temperature. 97.5% winter design temperature values are typically used by local codes. (Simplified Design of HVAC systems by William Bobenhausen)

Furnace, water heater vent pipe clearances - single wall pipe thimble at ceiling penetration, but double wall pipe is requiredA conditioned space is an area where temperature and humidity are controlled directly or indirectly.
An unconditioned space is an area isolated with doors and / or partitions from a conditioned space.

Typical examples of an unconditioned space are unheated attics, crawl spaces or garages.

  • Whenever the single wall vent pipe penetrates the roof surface, it requires thimble which must extend 18” above and 6” below the surface. Thimble must be open at the bottom and sealed around the vent pipe above the roof.
  • Horizontal section of the furnace, water heater single wall vent pipe cannot be longer than 75% of the vertical vent pipe length

Furnace, water heater vent pipe clearance – double wall

  • Typical listed and labeled double wall vent pipe clearance to combustible materials is one inch, but you should always check before installation.
  • Maximum horizontal section of the furnace, water heater double wall vent pipe cannot be longer than 100% of the vertical vent pipe length.

It will complete the information about the furnace and the water heater vent pipe clearance requirements.

]]>
Solid (Wood/Coal) Fuel-Burning Stove Chimney Venting https://www.checkthishouse.com/2691/solid-woodcoal-fuel-burning-stove-chimney-venting.html Tue, 03 Feb 2009 05:23:21 +0000 http://checkthishouse.com/?p=2691 Read more]]> As with every fuel-burning appliance, proper venting is always critical, and to enjoy your solid (wood/coal) fuel-burning stove, you have to get it right.

This guide is just an explanation of basic safety / code requirements for the solid fuel burning stoves. However, you should always consult stove installation with your local building code enforcement division, owners / installation manual, and / or local Certified Chimney Sweep (www.csia.org)

Every solid fuel-burning stove must have a chimney. Sidewall venting or through the roof venting using the interior type stovepipe is not acceptable and extremely hazardous.

The most popular chimney types for the solid-fuel burning stove are masonry, and a UL approved Stainless Steel Class “A” Insulated Chimney.

Solid-fuel burning stove (and fireplace insert) connection to the existing masonry type chimney.

1. The chimney should be examined first to ensure that it is in a good shape, and lined for this particular application. Older chimneys often lack the liner and might be heavily deteriorated, or even blocked. In addition, there is usually a heavy creosote buildup involved with a wood/coal burning stoves, which will be very hard to remove from the brick chimney without the liner. The most common type of the liner used for a wood/coal burning stove would be a UL approved stainless steel system.

Clearances for the solid fuel burning stove and a fireplace chimneyMasonry chimney installed on the house exterior wall is much harder to warm-up so it can provide proper draft. The liner (hopefully an insulated one) dramatically improves draft, and benefits discharge of the combustion products to the house exterior.

The minimum height of the wood/coal stove or the fireplace chimney (masonry or metal) would be 3’ above the roof surface and 2’ above anything within 10’ – of course, you can go higher, which usually improves draft.

2. If you have an existing liner in the masonry chimney:

  • it has to be at least the size of the stove collar
  • must be less or equal 2X of the stove collar diameter for the exterior chimney
  • must be less or equal 3X of the stove collar diameter if the only exposed chimney section is above the roof

3. You cannot just stick the stovepipe into the existing chimney or into the brick fireplace firebox and expected it to vent properly. It has to extend into the chimney flue liner, should be sealed at the liner connection, and below the smoke chamber . Otherwise, gaps around the pipe will cause your house air to dilute combustion products inside the chimney, lower their temperature and compromise proper draft.

4. If you have a manufactured, metal type fireplace, and your idea is to connect a wood/coal burning stove to its chimney, contact the fireplace manufacturer.

5. Remember to keep the stovepipe at a ¼” per foot rise towards the chimney entrance. Maintain at least 18” clearance (for single wall pipe) between the stovepipe and combustible materials, and 6” for a double wall (double wall pipe has a stainless steel interior pipe and black exterior surface). If your chimney is behind the paneling (or any other combustible) wall, you’ll have to remove this combustible surface to provide required spacing. It is possible to reduce those clearances by using approved shielding materials / clearance-reduction system.

UL approved Stainless Steel Class “A” Insulated Chimney

There are basically two types of insulated chimney installations:

1. Typical for a single story house – stovepipe runs straight up from the wood/coal stove and terminates below the ceiling level where it connects with an insulated chimney. From here, the chimney continues through the attic and roof or just through the roof if you don’t have an attic.

Typical side wall chimney installation for a solid fuel burning stove2. For any type of the house, especially if your stove is located close to the exterior wall – stove pipe runs from the appliance and terminates at the side wall (remember at least ¼” rise per foot towards the wall), where it connects with an insulated chimney. Special insulated connector passes through the house sidewall and angles up continuing to its required termination point. Do not use interior type stovepipe for the exterior and passing through the wall applications!

Wood burning stove minimum clearances from combustible materialsMinimum solid fuel (wood/coal) stove clearance to combustible material, unless otherwise listed and labeled by the manufacturer.

Always compare your appliance manual and local code with those minimums below.  Your particular stove design might require different clearances. They may be also reduced if an approved type of clearance-reduction system is used.

  • Front clearance of the solid fuel-burning stove – 18” min
  • Sidewalls and rear clearance – 36” min
  • Top of the stove clearance – 48” min

Bottom clearance for solid fuel burning stove:

  • with legs >6” tall – 2” thick masonry base with a metal shield
  • with legs providing 2”-6” clearance – 4” hollow masonry base + metal plate
  • if less than 2” clearance – entire floor underneath the stove must not be combustible (no hardwood floor under the masonry base permitted)

Some other requirements for the solid fuel burning stove installations

  • No garage installations
  • Fuel storage minimum  36” from the stove
  • No installation in an alcove or an enclosed space with a total area < than 512cu. feet
]]>
3 High Efficiency Furnace Plastic Vent Pipe Types (PVC, CPVC & ABS) https://www.checkthishouse.com/2606/high-efficiency-furnace-plastic-vent-pipe-types.html https://www.checkthishouse.com/2606/high-efficiency-furnace-plastic-vent-pipe-types.html#comments Mon, 26 Jan 2009 05:41:02 +0000 http://checkthishouse.com/?p=2606 plastic vent pipesPlastic vent pipe types listed below have been certified by the American Gas Association for use in furnaces classified as Category 4. These particular types of furnaces use positive pressure vent systems (exhaust gas temperature less than 1400F above the dew point temperature) and are always equipped with an induced draft motor that removes exhaust ... Read more]]> plastic vent pipes

Plastic vent pipe types listed below have been certified by the American Gas Association for use in furnaces classified as Category 4.

These particular types of furnaces use positive pressure vent systems (exhaust gas temperature less than 1400F above the dew point temperature) and are always equipped with an induced draft motor that removes exhaust gases from the appliance and discharges them to the exterior.

The dewpoint temperature is the temperature at which the air can now longer hold all of its water vapor, and some of the water vapor must condense into liquid water. (definition by weatherquestions.com)

High efficiency furnace PVC vent pipe types and specificationsProper installation of the vent system is essential for the condensing furnace (that’s another name for category 4 type furnace) to achieve maximum efficiency and to drain condensate efficiently from the system.

Make sure that your  installation complies with National, State and Local codes. Some of the furnace installation guides may be available online or obtained directly from the manufacturer.

There are 3 plastic types of pipes certified by the American Gas Association for use in high efficiency, condensing, category 4 furnaces: PVC, CPVC, and ABS

PVC  pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
F891 Cellular Core 158o ASTM F891
D2665 DWV Pipe ASTM D2665
D1785 SCH 40, 80, 120 ASTM D1785
D2241 SDR Series ASTM D2241

 

CPVC Pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
D2846 CPVC 41 212o ASTM D2846
F441 SCH 40, 80 ASTM  F441
F442 SDR Series ASTM F442

 

ABS Pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
D2661 SCH 40 DWV 180o ASTM D2661
F628 SCH 40 DWV Cellular Core ASTM  F628441

]]>
https://www.checkthishouse.com/2606/high-efficiency-furnace-plastic-vent-pipe-types.html/feed 3
Gas-Appliance Chimney Placement and Termination https://www.checkthishouse.com/2418/gas-appliance-chimney-placement-and-termination.html https://www.checkthishouse.com/2418/gas-appliance-chimney-placement-and-termination.html#comments Thu, 15 Jan 2009 03:44:12 +0000 http://checkthishouse.com/?p=2418

Furnace and / or water heater chimney requires proper placement and termination to safely discharge exhaust gases from the appliances combustion (fuel burning) process. Improper chimney placement and termination is often responsible for back-drafts, excessive corrosion of the chimney pipe walls, condensation, and Carbon Monoxide contamination of your house.

The rule explained on the pictures is just one of the several that have to be applied when installing the chimney. Make sure that you have a licensed professional performing gas water heater & furnace flue sizing calculations while replacing or adding any of those appliances in your home.

Chimney located less than 8' to the vertical wall must extend 2' above the roofFurnace and water heater chimney too low, must extend 2'min. above the roof if closer than 8' from vertical wallNatural (gravity) and motor induced draft type gas burning appliances chimney installed closer than 8’ from the vertical wall, must extend a minimum of 2’ above the roof placed over that wall.

Termination (height above the roof surface) of the gas-appliance chimney installed further than 8’ from the vertical wall are listed in the table below (relation to the roof slope). Based on International Residential Code and Uniform Mechanical Code

Termination of B and BW Vents based on [IRC 2426.6.5] and {UMC T8-1}
Roof Slope Height above Roof
up to 6/12 1′
>6/12 to 7/12 1’3″
>7/12 to 8/12 1’6″
>8/12 to 9/12 2′
>9/12 to 10/12 2’6″
>10/12 to 11/12 3’3″
>11/12 to 12/12 4′
>12/12 to 14/12 5′
>14/12 to 16/12 6′
>16/12 to 18/12 7′
>18/12 to 20/12 7’6″
>20/12 to21/12 8′

]]>
https://www.checkthishouse.com/2418/gas-appliance-chimney-placement-and-termination.html/feed 4
Proper Brick Chimney Crown Installation & Materials https://www.checkthishouse.com/2255/brick-chimney-crown-almost-never-done-right.html Mon, 05 Jan 2009 05:23:15 +0000 http://checkthishouse.com/?p=2255 Brick Chimney CrownBrick Chimney Crown A brick chimney crown – also known as a chimney termination cap, cement wash, or just a chimney cap – seals the chimney top opening around the flue and sheds rainwater / prevents moisture from deteriorating the chimney. For the chimney crown to fulfill its purpose, it must be properly shaped and installed. Unfortunately, after looking at hundreds of brick chimney on new and old houses, I’m wondering if the actual purpose of the chimney crown is ever taken into consideration. The overall appeal of the chimney crown and its complement of the house’s structure from the moment [...]]]> Brick Chimney Crown

A brick chimney crown – also known as a chimney termination cap, cement wash, or just a chimney cap – seals the chimney top opening around the flue and sheds rainwater / prevents moisture from deteriorating the chimney.

For the chimney crown to fulfill its purpose, it must be properly shaped and installed.

Unfortunately, after looking at hundreds of brick chimneys on new and old houses, I’m wondering if the actual purpose of the chimney crown is ever taken into consideration. The overall appeal of the chimney crown and its complement of the house’s structure from the moment it is built seems to be the only motivation.

There are 3 basic types of materials used to create a brick chimney crown:

  1. Concrete: it is the most popular and long-lasting chimney crown, assuming that it’s been properly installed
  2. Brick chimney covered with mortar: used often but extremely poor in performance
  3. Stone, which outperforms all materials if one solid block is used and properly installed – usually the most expensive type

The most common material used to manufacture the brick chimney crown is concrete. Such crowns are either pre-manufactured / delivered to the building site, or created on-site by pouring concrete directly on top of the chimney into the assembled form – this method is called “cast in place”.

Brick chimney crown should slope away from the flue at least 3 inches per footBrick chimney crown should have at least two and a half inch drip edgeChimney crown (flat) with crumbling mortar on top provides no water run-offA brick chimney crown made out of concrete should be at least 2” thick and have a 2 & 1/2” overhang (recommended by the Brick Institute of America) to protect the face of the brick wall it sits on.

The top surface of the chimney crown should slope away from the flue wall towards the crown exterior edge at a 3:12 pitch (3” rise for every 12” of the crown surface width). It would be ideal to have a crown-shaped this way when it is created, because mortar added on top of the flat crown will always separate, crack, and fall apart.

Pre-manufactured chimney crown - cracked, no expansion gap provided around the chimney flueCracked chimney crown - no expansion gap provided around the chimney flueThere should be a gap between the chimney crown and liner, filled with a flexible sealant, which allows for liner expansion. Without that gap and during the cold season, exhaust gasses warm-up the liner which expands, pushing against the much colder chimney crown, and causes it to crack.

Brick chimney crown - cement wash type, separating bricks due to water penetrationBrick chimney crown - cement wash type, inadequately sloped and crackingSeverely deteriorated brick chimney crown - cement wash typeThe cheapest type of a brick chimney crown is a design called a chimney wash. It is a layer of mortar, hopefully, pitched properly (3” slope for every 12” of a flat surface) / applied over the top course of bricks.

One winter season is capable of destroying it and by the time you’ll find out, the top section of the chimney requires rebuilding – add chimney crown seasonal evaluation to your home maintenance tasks list.

Brick chimney crown assembled from limestone blocks separating at mortar jointsStone chimney crowns (usually limestone) are usually very long-lasting but under two conditions – a single piece of a stone has been used and the flue penetration has some expansion space. Without the expansion joint, it will crack – just like the concrete crown. If it has been assembled out of several pieces of limestone (much cheaper than one solid piece), a brick chimney crown will separate at mortar joints and cause chimney structure deterioration.

]]>
Gas Water Heater and Furnace Chimney Flue Size Calculations https://www.checkthishouse.com/1887/gas-water-heater-and-furnace-chimney-flue-sizing.html Tue, 18 Nov 2008 03:55:13 +0000 http://checkthishouse.com/?p=1887 Furnace Chimney Flue Size CalculationsChimney Flue Size Calculations The following gas water heater and furnace chimney flue size calculations are based on Peoples Gas “Construction Guide for Gas Usage” in the city of Chicago and National Fuel Gas Code. Before applying any of the following rules, you must check your local building code requirements, and appliance manufacturer installation instruction. Have you checked your house brick chimney lately… or whatever type of the chimney you have? Did you have a new furnace or water heater installed / was your house chimney flue recalculated for those new appliances? Make sure that you chimney flue size / diameter is correct; [...]]]> Furnace Chimney Flue Size Calculations

The following gas water heater and furnace chimney flue size calculations are based on Peoples Gas “Construction Guide for Gas Usage” in the city of Chicago and National Fuel Gas Code. Before applying any of the following rules, you must check your local building code requirements, and appliance manufacturer installation instruction.

Chimney flue size - diameter must be properly calculated and installed - it is a serious safety issue!

  • Have you checked your house brick chimney lately… or whatever type of the chimney you have?
  • Did you have a new furnace or water heater installed / was your house chimney flue recalculated for those new appliances?

Make sure that you chimney flue size / diameter is correct; chimney flue size is one of the parameters that will help to achieve proper draft – the water heater and a furnace exhaust gases will be discharged safely to the house exterior – your life may depend on it. Some of the consequences of an excessive or insufficient chimney draft are:

  • Poor burner performance
  • Excessive combustion (burning process) noise
  • Improper combustion which could result in Carbon Monoxide spillage into the living area
  • Soot buildup inside and around the burner chamber of your appliances

The basic method for the chimney flue size calculations is “The Seven Times Rule” (applies to natural draft and / or fan assisted type appliances vented into the same chimney).

When two or more appliances are connected to a chimney, the flow area of the largest section of that chimney cannot exceed seven times the smallest flue collar, or draft hood outlet area, unless designed with approved engineering methods.

To make it simple – if you have a gas water heater with a 3” draft hood, and a furnace with a 4” flue collar connected to the same chimney flue, you’d calculate that chimney flue size based on the 3” draft hood – the smaller of two. So let’s calculate… or why don’t we skip those calculations and I’ll give you the answers:

The largest permissible flow area (in²) of the chimney flue for draft hoods or flue collars.
Diameter of Draft Hood Outlet or Flue Collar Flow Area (in²)
3″ 7.065
4″ 12.560
5″ 19.625
6″ 28.260
7″ 38.465

The Seven Times Rule application results:

The Seven Times Rule for appliances connected to a multistory common chimney
Smallest draft hood outlet or flue collar Largest section of vertical vent or chimney
3″ 7″
4″ 10″
5″ 13″
6″ 15″
7″ 18″

Q. Are those numbers sufficient for calculating you chimney flue size / diameter?

A. No, they aren’t! There are several other factors responsible for chimney flue size; chimney placement, height, lateral length of the vent pipe, type of the vent pipe, number and type of the connectors along the entire chimney flue run, size and category of the vented appliances…

So it’s always smart to have a professional calculating your chimney flue size. But, using the tables above will at least prevent many wild, way off the chart installations. Make sure that you have Carbon Monoxide detector installation performed according your local jurisdiction requirements!

If you’re looking for a gas water heater and furnace chimney flue size tables / guides covering most of the possibilities, try this publication by Hart & Cooley.

]]>
Chimney Inspection | Home Inspector Tips https://www.checkthishouse.com/874/chimney-inspection.html Tue, 26 Aug 2008 16:59:32 +0000 http://checkthishouse.com/?p=874 Chimney inspection - start from examining your chimney from the ground, binoculars may be helpfulHouse chimney inspection No climbing on and leaning the ladder against your chimney stack while performing chimney inspection! You are going to start chimney inspection by examining its structure from the ground. Depending on chimney’s height, position, roof pitch, and clearances around the house, you may be able to perform most of the chimney inspection from the ground level using a pair of good quality binoculars. House chimney inspection – masonry chimney For a brick chimney inspection (it would also apply to stone and cinder block) – check the condition of mortar lines between the bricks, and the bricks themselves. Heavily deteriorated / missing mortar [...]]]> Chimney inspection - start from examining your chimney from the ground, binoculars may be helpful

No climbing on and leaning the ladder against your chimney stack while performing chimney inspection!

Chimney inspection - start from examining your chimney from the ground, binoculars may be helpfulYou are going to start chimney inspection by examining its structure from the ground. Depending on chimney’s height, position, roof pitch, and clearances around the house, you may be able to perform most of the chimney inspection from the ground level using a pair of good quality binoculars.

House chimney inspection – masonry chimney

Chimney inspection - check for missing, deteriroated mortar and gaps between bricksFor a brick chimney inspection (it would also apply to stone and cinder block) – check the condition of mortar lines between the bricks, and the bricks themselves. Heavily deteriorated / missing mortar qualifies chimney for tuck-pointing.

Sometimes, portions of bricks and significant amounts of mortar are missing; this creates holes in the chimney walls and partial rebuilding might be required.

Chimney inspection - leaning chimneyThe same applies to a leaning chimney – unfortunately brick isn’t a flexible type of material, and a leaning chimney, sometimes separating from the house structure, would most likely require partial or complete rebuilding. Problems with the chimney foundations or with the way it was designed from the beginning (old, flue-less designs) might cause vertical cracks – these are dangerous and might allow Carbon Monoxide seepage into the living area, therefore, they require professional evaluation.

House chimney inspection – TV antennas

Chimney inspection - antenna attached to the chimney is often responsible for its deteriorationTV antennas attached to the chimney are often responsible for cracked mortar joints and may eventually cause the chimney to lean (especially on tall structures). Wind causes the antenna and its mast to vibrate, loosing up mortar joints, and creating cracks – it is probably better to secure it properly to the roof using a tripod type stand, using silicon under the brackets and on top of the screws (make sure that they are long enough to penetrate shingles and decking).

House chimney inspection – flashing

This next part may not be visible from the ground, so either hire somebody to check it for you, or if the roof is easily accessible and you feel absolutely comfortable doing it yourself, follow me:

Chimney inspection - metal flashing on a brick chimneyChimney inspection - roofing cement used as a chimney flashingFlashing on masonry chimneys is usually metal (copper, galvanized steel, aluminum), it should be sealed along the chimney walls and properly installed under the shingles – something called “step flashing” is usually required on a pitched roof.

Roofing cement is not a proper type of a flashing, but is often used when more than one layer of shingles is installed or the old flashing starts leaking. It might serve as a temporary fix but it will eventually crack and should be replaced with a permanent type of flashing as soon as possible.

House chimney inspection – masonry chimney crown

Chimney inspection - concrete crown on a chimneyChimney crown is designed to seal the chimney wall and to shed rainwater; sometimes it is a block of concrete, sandstone, or bricks simply sealed with mortar around the chimney flue. This part often deteriorates, cracks, or falls apart – small cracks should be sealed with rubberized compound (silicone, good quality exterior rated caulking) or they might expand during the winter if  water gets into them and freezes.

If large sections are missing or mortar has heavily deteriorated and opened gaps around the flue (exhaust pipe), it requires professional servicing.

House chimney inspection – metal crowns

Chimney inspection - metal crown on a chimneyMetal crowns (or better known as termination caps) may be corroded, have sunken, and now hold water – check for holes and seal around the flue pipe penetration. If you spot any gaps or holes in a metal crown of the chimney, chances are, its interior frame has been already compromised as well and requires servicing.

House chimney inspection – chimney rain cap and protective screen

Chimney inspection - rain cap with screenChimney inspection - rain cap with no screenChimney inspection - smashed rain cap might prevent proper ventingChimney rain cap and screen – install it if it’s missing. If it’s installed; it should not be damaged / smashed / collapsed / blocking the flue. There should be no bird nest around it or inside of it / some chimneys and their rain cap designs permit easy penetration of birds and sometimes rodents.

If your chimney has a cleanout at the base, you can use a flashlight and a small mirror to look inside – I’ve seen many dead birds, beehives, all kinds of debris, and one, very alive opossum – that’s one of the reasons to have a cap installed (screen recommended too).

House chimney inspection – metal chimney

Chimney inspection - corroded metal chimney wall - B ventChimney inspection - corroded metal chimney componentsLook for corrosion, holes, and loose parts on a metal chimney; rain cap brackets sometimes corrode and cause the cap to collapse and block the flue). Some metal chimneys come as one piece and any damaged parts would require the entire chimney to be replaced (usually applies to the sections sitting on top of the roof and posing as a brick chimney / square box surrounding flue pipe).

House chimney inspection – asbestos / transite pipe

Chimney inspection: asbestos - transite pipe chimney covered with cracksChimney inspection; close-up of a cracked and deteriorated asbestos transite pipe chimneyAsbestos / transite pipe chimney looks like a cement (grey color / unless painted) pipe, usually visible in the attic area or above the furnace, but may also have an exposed section penetrating the roof. If it is intact – no damage, cracks, deterioration … then itʼs fine (theoretically).

However, people are not happy with asbestos on the premises, even if it doesn’t require immediate servicing, because in case it becomes a problem, professional removal and disposal is quite expensive. So … take your chances. If it is damaged and reported by the inspector, it will most likely become an issue.

House chimney inspection – chimney flue

Please follow this link – chimney flue – to further explore it.

You’ll be able to easily discover many problems by following the above tips while performing your chimney inspection, just be careful!

]]>
Chimney Flue Requirements, Furnace and Water Heater Venting https://www.checkthishouse.com/72/chimney-flue-furnace-water-heater-venting.html Fri, 20 Jun 2008 18:07:44 +0000 http://checkthishouse.com/?p=128 Chimney Flue RequirementsProper furnace / water heater venting is an extremely important issue, which depends on the performance of the house chimney / chimney flue or other exhaust assemblies. The conditions explained in this post also apply to the wood burning appliances. Consequences of improperly assembled vent pipes, problematic chimney flue, deteriorating chimney walls can be sometimes fatal – fire and Carbon Monoxide poisoning are topping the list. Therefore, combustion products from your furnace, water heater, wood burning fireplace, and any other appliance that requires some kind of an exterior vent / chimney, have to be properly properly discharged to the exterior. Certain requirements [...]]]> Chimney Flue Requirements

Proper furnace / water heater venting is an extremely important issue, which depends on the performance of the house chimney / chimney flue or other exhaust assemblies. The conditions explained in this post also apply to the wood burning appliances.

Consequences of improperly assembled vent pipes, problematic chimney flue, deteriorating chimney walls can be sometimes fatal – fire and Carbon Monoxide poisoning are topping the list.

Therefore, combustion products from your furnace, water heater, wood-burning fireplace, and any other appliance that requires some kind of an exterior vent / chimney, have to be properly properly discharged to the exterior through its flue.

Certain requirements have to be met for the appliance’s chimney / chimney flue to draft properly. The most obvious one is unobstructed surroundings, in particular the roof itself. Depending on chimney placement / distance to the surrounding walls, there are different height rules.

For oil and wood burning appliances there is a very simple formula that regulates this chimney height requirement, it is called “3-foot, 2-foot, 10-foot rule”. What it means is that top of the chimney should be 3 feet above the roof surface through which it protrudes and 2 feet above anything within a 10′ radius measured horizontally (those are minimums).

This chimney rule can be applied to wood burning fireplaces, heating stoves and any oil fueled appliances, but remember that manufacturer requirements have to be incorporated into it.

Improperly installed water heater chimney / ventFor gas venting appliances, the chimney flue / venting rules are more complex, simply because of the variety of products on the market. For a double wall type vent (required in cold climates) I’ve prepared a separate post – Gas appliance vent terminations.

Below are some requirements for the furnace / water heater single wall vent pipe / chimney (warm climate):

  • Chimney / chimney flue must terminate min. 2′ above the roof
  • Chimney / chimney flue must terminate min. 2′ higher than building withing 10′
  • Chimney / chimney flue must terminate min. 5′ above the flue collar (e.g. water heater installed close to the roof framing would need at least 5′ long vertical vent pipe)
  • Single wall vent pipe requires minimum 6″ of clearance to combustible materials

General rule –  the chimney should not be outside a window or other house opening.

There’s several other requirements which apply to certain types of furnaces and water heaters venting. Always follow manufacturer guidelines, if you have any concerns about your chimney, call a heating contractor or other chimney specialist and have the chimney/heating system examined.

Never connect bathroom vent to the chimney flueSingle chimney with two flues, one for wood burning fireplace, second for gas appliances1. NEVER USE CHIMNEY FLUE TO VENT CLOTHES DRYER, KITCHEN / BATHROOM VENT

2. DO NOT USE SINGLE CHIMNEY FLUE TO VENT GAS AND SOLID FUEL (WOOD BURNING FIREPLACE OR HEATING STOVE) – you can have one chimney but multiple flues for different fuel types

3. READ MANUFACTURER’S INSTALLATION GUIDE and ask your licensed HVAC or plumbing contractor / installer if you have any concerns – installation guides are usually very clear, with simple diagrams explaining all required clearances, type of required materials, etc.

Chimney flue diameter downsized with new metal liner pipe4. If you’re replacing an old water heater (check water heater inspection) and a furnace (or any combination of those), with new appliances that also require regular chimney, make sure that your chimney flue is evaluated. Flue gases temperature in older, low efficiency furnaces (78% and less efficient), was sufficient to elevate chimney flue temperature to the point which guaranteed proper draft.

When connecting a new, regular type (known as category 1 type gas appliances) furnace /water heater, with efficiency slightly below 83%, old chimney flue size might need to be decreased with a new liner. This is extremely important, and serves various purposes – properly sized chimney flue:

  • prevents acidic condensate from forming on the furnace / water heater chimney flue walls
  • colder gases in large size chimney flue will not have enough energy to travel all the way to the  top and discharge safely beyond the property (becomes critical during cold season), they will condensate on cold chimney flue walls, cause deterioration and corrosion of appliance metal vent pipes
  • allows furnace / water heater combustion process gases to draft efficiently beyond the property
  • prevents flue gases from returning into the house, which would create potentially hazardous conditions, possibility of Carbon Monoxide poisoning

5. If one appliance has been disconnected from the chimney previously serving 2 or more appliances, make sure that a professional re-evaluates your chimney flue. It may need to be down-sized to prevent flue gas condensation and to provide proper draft (typical condition when upgrading to a high efficiency furnace) – check this chimney flue sizing guide.

This video below explains in detail how to install a new liner inside the chimney. It is 8 minutes long, but you’ll get a good idea about the entire procedure – this is an extremely important and often necessary procedure.

 

Water heater improperly connected to chimney flue with T type connector - not permitted when induced / forced draft motor appliance connected to the same flue as natural draft applianceFurnace and water heater properly connected to chimney flue with WYE type connector6. If you’re replacing natural draft furnace (no motor assistance for exhaust gases removal), with an induced / forced draft motor equipped appliance, and your natural draft water heater remains connected to the same chimney flue pipe, make sure that water heater vent pipe connection is “Y”, and not “T” type.

“Y” type vent pipes connection is necessary to prevent exhaust gases from mechanical draft type appliance vent pipe, from being pushed back into the natural draft type vent pipe, and contaminate living space.

Possibility of such contamination is greater during the cold season and on taller, exposed chimney / for example – attached to the side wall of the house. Before the hot exhaust gases warm up the chimney flue and create proper draft, they often discharge through the water heater’s draft hood.

Broken seal on high efficiency furnace PVC vent pipe connectionHigh efficiency PVC pipe and water heater vent pipe in the same chimney flue - not permittedHigh efficiency furnace PVC vent pipes exterior termination When upgrading to, or having a high efficiency furnace installed, exhaust gases will be discharged through the PVC pipe, and not the chimney flue.

There are two types of venting associated with those furnaces – single pipe and two pipe systems.

Because high-efficiency furnaces venting system must be air tight, PVC vent pipe connections should be monitored periodically during furnace operation for any moisture / condensation. If such occurs on PVC joints, you should have this condition evaluated by a licensed HVAC contractor – connection will have to be resealed.

PVC vent pipes should not be inserted into the chimney flue if it is still used for other appliances venting.

]]>
House Brick Chimney Problems & Leaking Masonry Chimney https://www.checkthishouse.com/71/chimney.html Sat, 03 May 2008 01:12:12 +0000 http://checkthishouse.com/?p=130 house brick chimney problemsHouse brick chimney is one of the most important, and at the same time neglected components of our homes, because we don't understand their functions.]]> house brick chimney problems

House brick chimney is one of the most important, and at the same time neglected components of our homes, and I think… for a very simple reason; because we don’t understand them, and they are not blocking our way to the kitchen or bathroom, we just take them for granted and forget about them… just like many other things.

Because majority of problems I’ve encountered during inspections have been associated with older, usually masonry / brick chimneys, first section will cover this particular type.

Huge number of the Chicago-land properties have been equipped with brick chimneys (I’m pretty sure that also applies to other parts of US), and many of those are dating all the way back to the late 1800 and early 1900. With properties exterior maintenance and improvements, brick chimney walls often received nice dressing, or maybe not as nice patches of various sources, just to keep them standing and to avoid costly rebuilding process.

But rarely anyone even considers checking interior of the house brick chimney, what’s even worse, with furnace / boiler and water heater replacement, professional / licensed installers sometimes “forget” about old brick chimney evaluation and often required modifications, putting in stake customers life.

Chimney Safety Institute of America reported in 1992 that “all unlined chimneys, irrespective of fuel used, are very liable to become defective through disintegration of the mortar joints.”

House Brick Chimney Problems - Missing chimney crown, liner, heavily deteriorated interiorDeteriorated / partially missing top section of the house brick chimney liner Deterioration of mortar joints and bricks is a natural, unavoidable process. However, proper maintenance, and replacement of mortar whenever is needed and necessary, protects bricks surface, and prevents, or at least slows spalling / delamination.

Unfortunately, with older brick chimneys, several other factors accelerate this natural process, and without taking care of them, exterior maintenance provides only temporary and rather cosmetic solution. Because, older brick chimneys often lack:

  • brick chimney liners (metal pipe, clay tile or ceramic material surrounded with exterior bricks),
  • brick chimney crowns (usually piece of pre-manufactured or made on site concrete block sealing top of the chimney and preventing water / moisture penetration), and
  • brick chimney rain caps (made of concrete, metal or clay, sitting above the liner section protruding from the crown), acidic exhaust gases from fuel (gas or oil) burning appliances, and water / moisture destroy interior surfaces, and without proper action, this progressing process might create fatal results.

Deteriorated upper section of the house brick chimney linerDeteriorated, partially missing brick chimney linerHouse brick chimney interior, deteriorated, partially missing clay linerHouse brick chimney interior, no liner, heavily deteriorated, missing mortar Notice on the pictures showing brick chimney interior missing bricks and mortar, partially missing liner sections. All that material has naturally fallen inside the brick chimney flue, and could be blocking it, creating extremely hazardous conditions – with blocked venting, CO (Carbon Monoxide) might contaminate your house air.

Leaning brick chimney, caused by the attached TV antennaTall cinder block chimney with separating blocks in middle sectionI wouldn’t suggest you going up on the roof unless you feel absolutely comfortable with doing it! Under no circumstances trying to claim up the brick chimney – don’t ever attempt to lean the ladder against it!!!, leave examination of a inaccessible brick chimney to the professionals!

Heavily deteriorated mortar between the chimney bricksMissing brick chimney crown allows for water penetrationThere are a few simple steps, you can take to get some basic idea about the condition of your brick chimney:

1. Check the house brick chimney from exterior, look for any deteriorated areas, missing mortar / gaps or holes between the bricks, separation from building structure (side chimney with 3 exposed walls / one shared with the building), leaning

2. Step further away from the building, so you can see upper section of the chimney, you should be able to tell if top has a crown, or if there’s a flue pipe / cap installed. Sometimes, the flue pipe might be even / flush with chimney crown, or have only small piece installed on top of the chimney to support the cap… if you can only see the edge of the last, top layer of bricks, get a professional because your brick chimney might look just like one from the pictures in this paragraph.

3. If you have access to the base section of the house brick chimney (in the basement, crawlspace, or sometimes house exterior), look for a small metal door, it might be heavily corroded, but if you manage to open it, get a powerful flashlight and a mirror.

You should be able to see at least part of the brick chimney interior, up to the appliance vent pipes penetration, and hopefully determine if it is lined – don’t be surprised, if after opening of the door all you can see is bricks, mortar, clay tile pieces, carefully pull it all out if possible to get a better look at interior (use gloves or some tool to remove debris to avoid injury). You may also notice chimney wall cracks, which pose serious hazard, especially if there’s no liner installed behind the bricks, or if existing liner is also cracked.

Water leaking from under the chimney clean-out door, or at the brick chimney base usually has 3 sources:

  • condensation on brick chimney interior walls often caused by poor drafting
  • leaking underground section of the chimney – just like old home foundations, older brick chimneys underground sections have no damp / waterproofing installed, and are subject to deterioration / water penetration

missing chimney crown and / or cap

Single wall vent pipe in attic area improperly attached to the old house brick chimney, missing chimney linerPartially missing attic section of the house brick chimney, exposed linerHeavy deteriorated attic section of the house brick chimney4. If section of your house brick chimney is accessible from the attic, use it to your advantage, but be careful in the attic, many have no floor boards, you have to step on ceiling joists, sometimes covered with insulation – drywall or plaster will not support you!.

You might find missing chimney bricks, holes, improperly connected appliance vent pipes, cracked or just falling apart chimney. You might also see a chimney built on an angle (this is called corbelled brick chimney), which is normal and as long as it’s in a good condition (look for displaced bricks, cracks, missing mortar), there’s nothing to worry about – it was designed this way for purely aesthetic reasons, to come out at the center of the roof. However, installing a new liner in corbelled chimney might be difficult.

If you’re planing furnace and water heater replacement (or maybe you’ve already replaced it), or just one of those appliances, have your brick chimney inspected, make sure that its flue dimensions comply with new appliance requirements, and if necessary install a new liner. This is critical when replacing one of the appliances using chimney venting with a high efficiency appliance.

For example, you used to have a furnace and water heater venting through an old brick chimney lined with a large diameter clay liner. Even though an older appliance’s efficiency was lower, they wasted more fuel in heating process, discharging significant amount of hot exhaust gases through the chimney, elevating chimney flue temperature to the level which guaranteed proper draft.

If you’ve eliminated chimney vented furnace / installed new high efficiency furnace using PVC pipe for venting instead of a chimney, and now have only water heater hooked up to that old, liner-less or with oversized liner brick chimney, you’re creating a pretty hazardous situation.

Exhaust gases from the water heater will not be hot enough to raise brick chimney’s interior temperature to such level which would guarantee adequate draft force. During cold months, gas exhaust flow rate through the chimney might be reduced to the point, where poisonous gases return into the house. The conclusion is a very simple one –

Never vent appliances (also applies to fireplaces) into an oversized chimney – if there’s any doubt – have it inspected by a professional, and check this chimney flue sizing guide!

Do not allow small house brick chimney problems to become a disaster!

]]>