WETT – Wood Energy Thermal Technology
Wood Energy Technology Transfer Inc. (WETT)
is a non-profit training and education association that promotes the safe and effective use of wood burning systems in Canada. With the cost of heating fuel climbing ever higher, more and more people are choosing wood burning systems to heat their homes. While this method offers a less expensive alternative to electrical and gas powered systems, it also poses a greater risk of fire. If your home or business is currently heated completely or partially by a wood burning device it is a good idea to have your system inspected by a certified WETT technician.
A WETT inspection involves examining the appliance for certification by a certified product testing company and confirming that all clearance requirements are met. If the unit is not certified the requirements are more stringent. A WETT inspection will verify the condition of the appliance, proper installation, appropriate ventilation, CSA certification (if any), approved chimney type and installation.
Before arranging for a Certified WETT Inspection there are some basic items you can check prior to calling for an inspection. You can also call prior to inspection for any information you may require. Call Roger at 705-795-8255
- Check the firebox for cracked firebricks or lining material. Replace any cracked firebricks to keep the firebox in good shape and prevent overheating which can warp steel components and turn the unit into scrap.
- Check the operation of the damper. Quite often dampers are seized or broken which can lead to unsafe or poor operating conditions.
- For masonry chimneys, replace any deteriorated or spalling masonry and caulk flashings as needed.
- Ensure rain caps are present to prevent water leakage inside chimneys and their liners.
- Clean the unit so a proper inspection can be performed.
- Visually check the firebox for any cracked firebricks, replace cracked firebricks to ensure the firebox is sound and prevent overheating which can warp steel, crack welds and destroy your woodstove
- Ensure flue pipes are properly secured with three screws per pipe connection or equivalent pipe clamps installed as per mfg. specs. Ensure the pipe fittings are oriented correctly and the pipe is also sloped correctly.
- Check the damper operation, door gasket for deterioration and the door glass for cracking.
- Ensure any heat shielding is secured and in good condition.
- Keep wood storage and combustible materials at least 4 feet away from the wood stove in all directions at ALL times.
There are two aspects to floor protection: thermal protection – protecting the floor from radiant heat from the bottom of the stove – and ember protection. For ember
Typical Floor Pad Layout
protection, you need to have continuous, non-combustible flooring under your appliance, extending 8” beyond it at the rear and sides and extending 18” in front of the wood loading door. Continuous means there can be no cracks where embers could get down to combustible material. So, patio stones or bricks won’t work unless you grout between them. If you have a certified appliance, you don’t need to worry about thermal protection. The legs are designed to be long enough to keep the firebox far enough from the floor that the floor won’t get too hot. If you have an uncertified appliance, you will need to have additional thermal protection under the stove.
The flue pipe is the pipe that connects the appliance to the chimney. Measure the distance between the pipe and any combustible construction. Required clearance around the standard single wall flue pipe is 18”. Double wall flue pipes have a sticker stating the required clearance (usually 6”).
Installation Guidelines from Woodheat.org
- Maximum overall length of straight pipe: 3 m (10 ft.) Typical Chimney Installation
- The assembly should be as short and direct as possible between the stove and chimney. The use of two 45 degree elbows is often preferable to a single 90 degree elbow because less turbulence is created in the exhaust flow and they result in less horizontal run.
- Maximum number of 90-degree elbows: 2. Maximum unsupported horizontal length: 1 m (3 feet).
- Galvanized flue pipes must not be used because the coatings vaporize at high temperatures and release dangerous gases. Use black painted flue pipes.
- 6-, 7-, and 8-inch diameter flue pipes must be at least 24 gauge in thickness.
- Flue pipe joints should overlap 30 mm (1 1/4 in.)
- Each joint in the assembly must be fastened with at least three screws.
- The assembly must have allowance for expansion: elbows in assemblies allow for expansion; straight assemblies should include an inspection wrap with one end unfastened, or a telescopic section.
- Minimum upward slope towards the chimney: 20 mm/m (1/4 in/ft.).
- One end of the assembly must be securely fastened to the flue collar with 3 sheet metal screws and the other end securely fastened to the chimney.
- There must be provision for cleaning of the pipes, either through a clean out or by removal of the pipe assembly. Removal of the assembly should not require that the stove be moved.
- The crimped ends (male) of the sections must be oriented towards the appliance so that falling dust and condensation stay inside the pipe.
- A flue pipe must never pass through a combustible floor or ceiling or through an attic, roof space, closet or concealed space.
- Minimum clearance from combustible material: 450 mm (18 in.). The minimum clearance may be reduced by 50 percent to 225 mm (9 in.) if suitable shielding is installed either on the pipe or on the combustible surface.
Don’t put your family’s safety at risk. Maintain wood heat safety requirements by education and proper installation.
Call Roger at 705-795-8255 for your Certified WETT Inspection
Email Roger for appointments or questions
We provide WETT inspections to Angus, Alliston, Barrie, Bradford, Brechin, Collingwood, Everett, Innisfil, Lisle, Midland, New Lowell, Orillia, Penetang, Ramara, Stayner, anywhere in Simcoe County.
A WETT Certified Inspection is only $75.00 when included as part of Home Inspection.