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Wett Inspections and Insurance

Wett Inspections and Insurance company – Most companies want a WETT Certified Inspection

WETT inspections and Insurance companies go hand in hand.  Most insurance companies today require that you obtain an inspection of your wood burning appliance by a WETT  (Wood Energy Technology Transfer) Certified Inspector.  WETT is the governing body who work with insurance underwriters and government bodies, to ensure safe installations and provide standards for inspections and insurability of wood burning appliances, such as wood stoves and open fireplaces.

There was a tendency during the development of the first round of EPA wood stove emissions regulations in the 1980s to rely exclusively on science and technology to reduce emissions from wood heaters. This made perfect sense at the time because most wood stoves were crude boxes with virtually no emission control technologies. Unfortunately, a repeat of this approach appears to be reflected in much of the recent commentary surrounding the EPA New Source Performance Standard (NSPS) review process. Unfortunate because this repeat of the reliance entirely on technology can result in appliances that burn cleanly under laboratory conditions through increased technological complexity but which do not meet user needs. This could produce disappointing emission reduction results in actual use.

Sawdust or other waste biomass material is compressed into small cylinders about 8 mm in diameter and from 10 to 30 mm long to produce pellets. The raw feedstock for pellet production does not include binders or other additives, except in some cases to assist in the extrusion process. In the pellet stove, the fuel is moved from the integral hopper to the small combustion chamber by a motorized auger. The exhaust is forced into the vent with a fan. Because steady state combustion can be approximated by adjusting the fuel and air mixture, pellet stoves can burn with lower emissions, on average, than wood stoves. In contrast, the combustion of a batch of wood in a wood stove never stabilizes, so combustion air requirements are constantly fluctuating and good combustion conditions are transitory. Pellet stoves deliver about the same efficiency as EPA certified natural firewood-burning stoves.

Creosote, a crusty deposit left behind by the smoke that drifts up your chimney, can ignite into a dangerous fire when it builds up. To reduce the build up of creosote burn only clean, well seasoned wood that has been split and dried properly. Dry wood lights faster, burns better and produces less smoke than “green” wood – a major culprit in creosote buildup. You should think twice before you chop up that old furniture and toss it into your wood stove.

Burning garbage, plastic, particleboard, plywood, salted driftwood or any other painted or treated wood releases a toxic cloud of chemicals and can build up creosote. A standard home inspection includes a visual assessment of the components of the fireplace, hearth and chimney. However, depending on your area and the property insurance you choose, a WETT inspection may be required.

Wood, however, differs from fossil fuels such as oil and gas because it is carbon neutral. The term “renewable” refers to the fact that trees recycle CO2. As a tree grows, it uses CO2 from the air as a source of carbon to build its structure. This carbon makes up about half of the weight of wood. When wood is burned, it decomposes rapidly, and CO2 is released into the atmosphere again. A similar amount of CO2 would be slowly released if the tree died and was left to rot on the forest floor. As a result, wood heating doesn##Q##t contribute to the problem of climate change the way fossil fuel use does. But wood fuel is truly renewable only if it is produced by using sustainable forestry practices.

The Barrie Home Inspector is a WETT Certified Professional Home Inspector for the Barrie, Alliston and Orillia area of Simcoe County. The experience and knowledge from over 4,000 inspections allows us to guarantee the best possible WETT and Home Inspection. The Barrie Home Inspector is also a Certified Building Code Official with the Ontario Building Officials Association.

WETT Certified Appliances

A Certified Appliance is a unit which has been tested by a “recognized testing facility” (Underwriters Laboratories of Canada,  Underwriters Laboratories, Warnek Horsey and CSA) and typically have a plate or sticker usually located on rear of appliance listing requirements of installation.  When your wood burning appliance bears one of these labels it means the Products bearing the Warnock Hersey (WH-ETL) Mark or ULC etc, and  indicate compliance to relevant building codes, association criteria, and product safety and performance standards.

Insurance is part of wood heat safety, and making your system safer ensures you the best possible premium for your insurance. Call your insurance representative to review your coverage and inform him or her when you make any changes. This includes adding or changing a wood stove, modifying a chimney – anything that may influence the safety of your system. Your insurance representative will want to know if your unit is certified by Underwriters’ Laboratories of Canada (ULC) or the Canadian Standard Association (CSA) and may refuse to insure your home if the stove is not certified. He or she will also want to know if your unit was installed by a professional and if the clearances are up to the latest Building Code and Fire Code, including a proper floor pad, venting system and so forth.

Wood burning appliances fall into two distinct categories. Uncertified appliances are typically older units that have never under gone the rigorous testing required to obtain a Certification by a testing laboratory.  Certified appliances have been tested by one of the registered laboratories, i.e. CSA, ULC, OTL or Warnock-Hersey, and have passed all requirements.

I actually attended a “woodstove certification testing” in Toronto and was amazed at the detail of testing.   First, it is the manufactures responsibility to determine the safe distances Certification Label - Alliston WETT Inspectionsrequired to combustible construction,  that information is part of the installation instructions.   ULC in this case, set the stove up in accordance with the installation instructions and then placed “heat sensors” around, below and above the wood stove.   The wood stove was then fired up and ran for an hour or two as measurements were taken from all the different sensors.  If any sensor indicated heat above the testing limits, the unit would fail.   Most manufactures tend to err on the side of safety when specifying distances to combustibles as the cost of one test was over $15,000 dollars ten years ago.

If you are purchasing a home equipped with a wood burning device, it is very important to add a clause to your offer that unit pass a WETT inspection to determine whether the unit is installed correctly and is safe to use.  Many older units are very unsafe and even chimney’s that were allowed 15 to 20 years ago may not be allowed today. On one such visit we found an uncertified appliance located within 4 inches of an unshielded combustible wall.  A type chimney’s were used in past years and can still be used today as long as original configuration is left intact.  If you were to upgrade or replace your wood stove you would no longer be able to use A type chimney and replacement would be required.

Every part of your wood stove or wood burning appliance has to be installed in accordance with the manufactures instructions.  If you install a stainless steel chimney all parts used have to be approved by manufacturer.  If in doubt call the manufacture or their local representative to find out what products can be used in conjunction with theirs.

Check with your insurance company prior to installing any wood burning appliance.  Some insurance companies will not insure an installation unless installed by a WETT Certified Installer.   Even if  they do accept your installation they may require a level 2 WETT Inspection which could significantly reduce money saved by doing installation yourself.

If you are buying a new home and the fireplace or wood stove has been used on a regular basis then it is recommended that you hire a WETT Certified Chimney sweep to clean your chimney and provide you with a WETT Inspection.   The heavy build up of soot and creosote would prevent some doing a Site Basic inspection from viewing any cracks in flue pipes etc due to buildup in chimney.   So protect your home and your family by having a WETT Certified Inspection of your wood burning appliance.

Pellet Stove Installation

Pellet Stove Installation.  Wood pellet stoves are generally small, and the bags of pellets are about the size of a mulch bag, making them easy to store. They’re also easy to operate; they on­ly require loading pellets and igniting the flame. And depending on what size hopper your stove has, it may need to be loaded only once a day.

pellet stoveWood pellets are made from recycled materials and are heavily compressed, which reduces the moisture content. Dry fuel creates more heat, causing the pellets to burn hotter and cleaner than their wood counterparts. Wood pellet stoves also emit fewer pollutants than traditional fireplaces. They’re considered to be carbon neutral by many environmentalists, due to the fact that the pellets are made from trees that lived on carbon, so the two cancel each other out. The pellets also are inexpensive, and you can purchase them in small quantities as needed, versus the upfront costs of purchasing a cord of firewood.

Most modern pellet stoves do not require the same type of chimney as a conventional wood stove or fireplace, you usually will have many more options where it can be located. You will require  a 3-inch flue to exit out the back or top of the stove, go through the wall or extend out through the roof.  The majority of pellet stoves are vented out the sidewall.

The outer surfaces of a pellet stove do not get as hot as wood stoves or fireplaces, so most can be placed closer to combustibles—typically 3 inches from walls at the sides and 1 inch from a back wall. Most need to stand on a non-combustible surface such as stone or tile that is at least 3/8 inch thick. Be sure to read and follow all of the manufacturer’s requirements regarding clearances.

Pellet Vent pipe, pipe is classified as L-Vent pipe, can be bought in two sizes, either in 3 inch or 4 inch diameter. The L-Vent pipe is the correct type of pipe for your pellet stove. The inside portion of the chimney is made from Stainless Steel and can last as long as your pellet stove.

Common Clearance Restrictions


  • Cannot be less then 3 feet above any forced air inlet located within 10 feet of the exhaust pipe.
  • Cannot be less then 4 feet below or horizontally from, or 1 foot above, any door, window or gravity air inlet into any building.
  • Cannot be less then 2 feet from an adjacent building and less than 7 feet above grade when located adjacent next to a public walk way. Mobil home installations must use a spark arrester.
  • Termination should not be located where it might ignite trees, shrubs, dry grasses or be a hazard to children as exhaust gases can reach 500 degrees and cause serious burns if touched.
  • Do not install vent pipe into chimneys shared by other appliances, as you can get a back draft and causing the exhaust from one to the other appliances to come back into the home through the other appliance.

Vent Length Calculations

The first configuration example is straight out the back of the stove and through the wall with at least 10 to 12 inches protruding past the outside wall and the altitude being less than 3000 ft. Looking at the EVL parameters, we know that each horizontal foot equals 1 EVL. For this installation typically we have about 2 horizontal feet, which equals to no more than 2 EVL. This is way below the EVL  of 15 so 3″ pellet vent pipe would be the correct size pipe to operate the pellet stove. The through the wall and terminate is most popular and the least desirable of installations as it can soot and stain the outside wall of the home.

Another example of type of venting installation is in the corner of a room and the altitude is less than 3000ft. This is comparable to the first style configuration with an added 45-degree elbow to allow for the corner. In this configuration a 3-foot pipe is usually need to exit the home to maintain the one-foot clearance on the outside. So let’s begin the calculation. The EVL of 3 feet horizontal is 3. The EVL of the 45-degree elbow is 3 as well. Adding that together you get a total EVL of 6. This is way below the EVL of 15 so a 3″ is adequate size pipe to install for the pellet stove.


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