WETT Certified Inspection

WETT Certified Inspection

Here are some of the common problems found during a WETT Certified Inspection.  As a home owner you can check your wood burning appliance before arranging for an inspection.  This can save you time and money.   Also if you are installing your own appliance it can help you comply with the required installation and safety standards.

Hearth Extension 

Fireplaces shall have a noncombustible hearth extending not less than 400 mm (15 3/4 in) in front of” title=”View all articles about fireplace here”>fireplace opening measured from the facing, and not less

Barrie WETT Hearth Inspecton

Large Fireplace Hearth

Where the fire chamber floor is elevated more than 150 mm (5 7/8 in) above the hearth,the dimension of the hearth measured perpendicular to the plane of the fireplace opening shall
be increased by not less than
(a) 50 mm (2 in) for an elevation above 150 mm (5 7/8 in) and not more than 300 mm
(11 3/4 in), and
(b) an additional 25 mm (1 in) for every 50 mm in elevation above 300 mm (11 3/4 in).

When a fireplace opening is greater that 6 sq ft require a hearth that extends 20 in in front and 12 in to each side.

If the fireplace opening is less than 6 sq ft a hearth extending 16 in to the front and 8 in to each side.

Chimney Inspection

One of the most valuable items you can install on your chimney is a rain cap.  A $25.00 chimney cap will prevent water, snow and debris from entering your chimney.  Water, Masonry and Winter Freezing Cycle can do a lot of damage to your chimney and also cause some safety issues.

Modern chimney’s have to have a prefabricated or poured on site chimney cap with drip edge.  Older masonry chimney caps tend to crack and allow water to penetrate into chimney structure.  Unless you are regularly inspecting and sealing cracks in older chimney caps,  most likely there is some deterioration occurring.  Once the water penetrates the cap it starts attacking bricks, mortar and chimney flue liners.

Flue liners can become cracked or mortar deteriorated and missing.  This will require repair by a mason prior to inspection.  Many times if clay flue liners are damaged the home owner will opt for installing a stainless steel” title=”View all articles about liner here”>liner.

Height of Chimney

The top flue of your chimney must be a minimum of 3 feet above roof at chimney base.   It must also be at least 2 feet above any roof feature that is within 10 feet.

WETT Chimney Height Rule

Chimney Height Rule

Weather Resistant

The outer surface of your chimney should be weather resistant.  The top of chimney cap where” title=”View all articles about liner here”>liner passes through should be sealed with caulking.  Mortar joints should be shaped to shed water.  The freeze / thaw cycle can deteriorate bricks.  Masonry chimney’s need periodic maintenance to repair cracks in caps and caulking.


Inspect flashings to ensure they are tightly fitted against brick surface, for corrosion or rust.  Caulking maybe required to ensure adequate seal.  Any corroded or rusted flashings should be replaced.

Type A Chimney’s

These types of factory built chimney’s were used until the late 1970’s where it was discovered that the metal could buckle with the extreme heat of a creosote fire.  Although still in use, this  Type A chimney’s should be closely inspected for any signs or corrosion or failure.   If installing a new wood burning appliance, the Type A chimney must also be replaced.

Chimney Cleaning

Depending on how often you use your wood burning appliance should dictate how often you clean it.  Every chimney should be cleaned annually and if used as a heat source during the winter, twice or more is probably a good idea.   If your chimney has seen a lot of use then it is recommended you have it inspected by a WETT Certified Chimney Sweep as Creosote can hide cracks and missing mortar etc. Read more about Chimney Cleaning

Wood Stove

Certified Wood Stove

The very first question I ask my clients when calling for a Wood Stove inspection is; ” Is your stove Certified?”.   A Certified Wood Stove has a data plate, usually located on the back, which

Certification Label - Barrie WETT Inspections

Certification Label

indicates that unit was tested in accordance with a Listed Agency and it will display the clearances required to combustible products.  It will usually also indicate the clearance required for stove pipe, whether single wall or double.  Older stoves may also have minimum hearth pad dimensions. CSA, Underwriters Laboratory (ULC), WarnockHersey, and OMNI  Laboratories are typical Testing Agencies found on label.

Uncertified Wood Stoves

If your wood stove does not have a label indicating it was tested by one of the above agencies, then it is an uncertified wood stove.  The minimum clearance to any combustible on front , sides and rear is 48 inches.   Although clearances can be reduced by using approved shielding methods,  most home owners opt for buying a new wood stove.   The new models of wood stoves have very small clearance requirements and they are quite energy efficient  compared to older models.  EPA requirements also require cleaner burning stoves which requires less chimney cleaning and more efficient fuel burning.

Floor Protection

There are two types of required floor protection: thermal protection – protecting the floor from radiant heat from the bottom of the stove – and ember protection. For ember 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.


For more information on obtaining a Certified WETT Inspection of your wood burning appliance,  Call Roger at 705-795-8255



What is a WETT Inspection? Do I Need One?

What is a WETT Inspection? Do I need one?

A WETT inspection,  short for Wood Energy Technology Transfer, is a thorough inspection of all types of wood burning appliances.  This includes fireplaces, fireplace inserts, wood stoves, pellet stoves and outside boilers.

Fire is always a threat to a home and a WETT Inspection can provide “Peace of Mind” for the homeowner and his family.  Also many insurance companies now require a WETT inspection prior to issuing a Home Policy.

Many older homes and cottages have Wood Burning Appliances that will not meet the requirements of a WETT Certified Inspection.  Older wood stoves may not be certified by a rating agency such as UL, ULC or Warnock Hersey.   This means that the minimum clearance to combustibles for an uncertified stove is automatically 48 inches.   So unless your wood stove is in a basement you will probably be out of luck.

A WETT inspection is an inspection carried out by an inspector who is WETT Certified.  Below is a list of items that may be inspected by your WETT Certified Inspector on a Wood Stove, Pellet Stove or Fireplace inspection:

Typically, when people are looking for an insurance type of inspection, WETT certified inspectors conduct a visual Level I inspection to determine if there is evidence of any problems with the installation.

The Level I inspection is essentially a general overview of the readily accessible parts, clearances, chimney heights, stove location with respect to combustible materials and visual signs to determine if the system meets the CSA Standard B365 (Installation Code for Solid-Fuel-Burning Appliances and Equipment).

Call Roger at 705-795-8255 for your WETT Certified Inspection

Email Roger to arrange an appointment.

If you are installing your own appliance, call for information that may save you time and money.  Advice on installation is free and available any time.

Read our articles on various parts of wood burning equipment to find out about proper installation, maintenance and safety requirements.

Frequently Asked Questions

What areas do you provide service to?

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.

Does My Chimney Require a Liner?

If you are installing a Fireplace Insert then you chimney requires a stainless steel” title=”View all articles about liner here”>liner to be installed.  Also liners maybe installed when there is damage to flue tile.

How Often Should I Clean My Chimney?

To be sure that all of your systems are in working order and operating as they should, it is recommended that homeowners get an annual chimney inspection. Most homeowners opt to have a Chimney Cleaning done every year as well, especially if they use their fireplace on a regular basis. Other venting systems connected to furnaces and stoves should also be cleaned on a regular basis to maintain safer operation.

What is a Fireplace Insert ?

Fireplace Inserts are essentially a well-designed wood stove that fits inside a fireplace firebox, which transforms the fireplace into a viable source of heat. Fireplace inserts are typically installed inside masonry fireplaces.

What is Creosote ?

Creosote  is the substance which is deposited in the chimney whenever a fire is burned, though some fires result in more creosote deposits than others, and is an unavoidable part of using a fireplace. Creosote is black, sooty, and tar-like; and it is dangerous enough that minimizing the amount of creosote in your chimney is an important safety consideration. If too much creosote builds up in your chimney, there is a much greater possibility of a chimney fire, which is extremely dangerous and often leads to deadly house fires.

Can I Reduce Clearance to Combustibles?

Yes clearances to combustibles can be reduced by up to 67% using an approved method and material to construct a heat shield.  Read article on Reducing Clearances.


Reducing Clearances

Reducing Clearances

Air-Cooled Radiation Shields Clearances are designed to keep combustible materials around a wood burning appliance below 90°C (190°F), even during a chimney fire. It is possible to build an air-cooled radiation shield, which can reduce clearances because moving air is a very effective cooler.

When radiation from an appliance hits a shield and heats it, the shield in turn heats the air behind it. Since hot air rises, the air moves up and exits through spaces at the top of the shield, andWETT Clearance Chart cooler air is drawn in at the bottom of the shield to replace it. The hotter the shield gets, the faster the heated air rises, and the more air passes by the shield, cooling it down.

A shielding system made of small sheet metal panels is less likely to buckle than one made of a single large sheet. The edges of the metal should be hemmed to improve its strength and appearance. This kind of system is inexpensive and easily adapted to many situations.

Wall shields must extend at least 450 mm (18 “) beyond each edge of the appliance and 500 mm (20”) above the appliance. To allow air to flow behind the shield, there must be a space of at least 25 mm (1 in.) at the bottom of the shield and a 21 mm (7/8 in.) space between the shield and the wall. (If the shield must extend up the wall to shield the flue pipe, a 75 mm (3 in.) space must be left at the top so the cooling air can escape).) The shield should be permanently mounted on the wall using screws through non-combustible spacers.

Shield Construction Rules

  1. Minimum space between shield and combustibles: 21 mm (7/8 in.).
  2. Minimum clearance along the bottom of shield: 25 mm (1 in.).
  3. Maximum clearance along the bottom of shield: 75 mm (3 in.).
  4. Minimum clearance along the top of shield at ceiling: 75 mm (3 in.).
  5. Shield extension beyond each side of appliance: 450 mm (18 in.).
  6. Shield extension above appliance: 500 mm (20 in.).
  7. Edge clearance for ceiling shields: 75 mm (3 in.).
  8. Adhesives used in shield construction must not ignite or lose adhesive qualities at temperatures likely to be encountered.
  9. Mounting hardware must allow full vertical ventilation.
  10. Mounting hardware must not be located closer than 200 mm (8 in.) from the vertical centre line of the appliance.
  11. Mounting hardware which extends from the shield surface into combustibles may be used only at the lateral extremities of the shield.

Air-cooled shields for ceilings should have a 75 mm (3 in.) clearance from adjacent walls.

Certified Commercial Shields

If you do not want to build an air-cooled radiation shield, several different styles of metal and brick or stone commercial shields are available. Be sure that any commercial shield you buy has been certified and labeled by one of the three recognized testing agencies. The manufacturer’s instructions will specify how to install the shields, and the clearance reductions that can be achieved.

What Can Shields Be Made Of?

  •  Sheet metal with a minimum thickness of 0.33 mm (0.013 in.). This is only 30 gauge -26 gauge is better. The edges should be hemmed (safety edge). WETT Clearances
  • A solid brick wall at least 21 mm (7/8 in.) away from the wall and vented at the top and bottom.
  • Brick or tile slices mounted on an approved non-combustible board with a 21 mm (7/8 in.) air space behind it.
  • A certified commercial shielding system.

Note:  If a brick wall is built against a drywall or other form of combustible wall.  The measurement for clearance is taken from appliance to combustible wall.  You would consider the brick not to be there when determining distance.  That is why it is important to know the requirements before constructing heat shields to ensure that they will comply with WETT Inspection.

The first step in reducing clearances is to determine the minimum clearance, either from the appliance label or from the table of clearances for uncertified appliances. Then, calculate the permissible clearance reduction for the type of shield you plan to use from the table on clearance reduction. The channel spacers shown are the most effective type to use because they give good support to the shield and do not transmit heat through the mounting hardware to the combustible wall. Metal wall strapping, available from most building supply stores, is made of light steel channels that work well as shield spacers. Note that the bottom of the channel is notched to allow cool air to enter. The shield must extend 450 mm (18 in.) beyond each edge of the appliance and 500 mm (20 in.) above the top of the appliance.

Floor Protection

The floor pad must be made of a durable, noncombustible material, such as sheet metal, grouted ceramic tile, or mortared brick. Floor pads must normally extend not less than 450 mm (18 in.) in front of the loading door and 200 mm (8 in.) beyond the other sides and back. Floor pads must not be installed on carpet unless the pad is structurally supported so that it does not move or distort.  Most Fireplace shops now carry prefabricated ULC approved floor pads which can be easily placed in front of” title=”View all articles about fireplace here”>fireplace is hearth is not the required size.

Floor Pad Size

The floor pad protects flooring from hot embers that might fall from the appliance during fuel loading or servicing. The pad should extend at least 200 mm (8 in.) beyond the sides and rear and 450 mm (18 in.) in front of the loading door. The floor pad must be a continuous, non-combustible surface. The floor pad must not rest on the carpet unless it is strong enough to resist bending or cracking. The best floor pads are laid on the sub-floor so that their finished level is flush to the floor, so there is no edge to trip on.

If you are installing your own wood stove or fireplace insert you can call Roger at 705-795-8255 for requirements prior to doing work.

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