Fireplace Construction Information

 

Fireplace construction is governed by the Ontario Building Code,  from 9.21.1.1 to 9.22.10.2, which covers installation of fireplace inserts and hearth mounted stoves. The Ontario Building Code is  available online.  Click to view
9.22.10.2 provides the authority for these appliances to conform to CSA B365, the installation Code for Solid-Fuel-Burning Appliances and Equipment

Fireplace Construction Deficiencies

 

Combustion Air  ( OBC 9.22.1.4. )   (1) Every solid fuel-fired fireplace, including a factory-built fireplace, shall have a supply of combustion air from outdoors. Since 1990 Masonry Fireplaces have been required to have a combustion air source from outside installed.  Older fireplaces which are inspected today would have an observation that they are non-compliant.

Hearth Extension ( OBC 9.22.5.1. )  (1) Except as required in Sentence (2), fireplaces shall have anoncombustible hearth extending not less than 400 mm ( 16 inches ) in front of the fireplace opening measured from the facing, and not less than 200 mm ( 8 inches ) beyond each side of the fireplace opening.  Many older fireplaces only have a 12 inch ( 300 mm ) Hearth Extension which would be non-compliant.  There are ULC rated Hearth Pads which can be used to make unit compliant.

Heat Duct Openings ( OBC 9.22.9.4. )  

(1) The clearance of combustible material above heat circulating duct openings from those openings shall be not less than,

(a) 300 mm ( 12 inches ) where the combustible material projects not less than 38 mm ( 1 1/2 inches ) from the face, and

(b) 150 mm ( 6 inches ) where the projection is less than 38 mm.

Chimney Flues ( OBC 9.21.4.4. )  (1) A chimney flue shall extend not less than,

(a) 900 mm ( 3 feet ) above the highest point at which the chimney comes in contact with the roof, and

(b) 600 mm ( 2 feet ) above the highest roof surface or structure within 3 m ( 10 feet ) of the chimney.

Lateral Stability ( OBC 9.21.4.5. ) 

(1) Except as provided in Sentence (2), chimneys shall be braced in accordance with Subsection 4.3.2. to provide stability under wind loads.

(2) A chimney need not be laterally braced provided,

(a) no horizontal outside dimension is less than 400 mm ( 16 inches ) , and

(b) the chimney extends not more than 3.6 m ( 12 feet ) above a roof or the masonry wall of which it forms a part.

Site Built Chimneys

 

Masonry fireplaces, built of bricks, blocks or stone and mortar, are typically massive structures which can weigh between 6 and 7 tons.  They are archteturally pleasing, long lasting, and can add  value to your home. Care and periodic maintenance will ensure that they give you a lifetime of enjoyment.

Masonry fireplaces require an properly sized footing for support or they can shift and crack, allowing  fire to contact  nearby combustibles. It is important to  keep an eye out for any signs of settling or movement. Inside the firebox, where the facing material meets the firebrick, is one weak spot where this settling often first appears. You can keep settling problems to a minimum by directing downspouts away from the fireplace foundations and by sloping the ground around the fireplace to ensure proper drainage.

Masonry is quite durable, and in fact is often seen as an everlasting product. This is not true for chimneys. While the brick on the house receives some protection from the eave, the chimney is exposed to every raindrop and has to endure the endless freeze/thaw cycle during winter months. A quality chimney cap will keep the crown in good repair, and a waterproofing treatment, are some ways to avoid expensive repairs or rebuilding. 

The firebox takes the brunt of the fire’s heat and it requires constant attention. The firebrick is designed to take the heat from fire, but over time the joints will fail from the constant expansion and contraction. In addition, refractory mortar is specified and not always used. In a fireplace without a chimney cover, the rain water will pool on the smoke shelf, mix with the soot behind the damper, and form an acidic slurry that can destroy the mortar joints. Keeping these joints in good repair with a high temperature refractory mortar will help ensure the fire is contained.

The tile liners used in most masonry fireplaces are fine as long as the fireplace is properly maintained and not exposed to chimney fires. One good chimney fire will usually crack these tiles, rendering them ineffective. The general rule of thumb is that a masonry fireplace should be swept before 1/8″ of soot accumulates. If you experience a chimney fire, it is very important to have the chimney swept and inspected before you use it again. 

Unlike prefabricated fireplaces, a masonry fireplace is built on site brick by brick, giving the mason ultimate control of the final product. This results in a wide range of masonry fireplaces available. With proper care and maintenance, Most masonry fireplaces can provide you with many peaceful, relaxing hours.

What is WETT ?

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.  We provided WETT Certified Inspections to Angus and Essa Township.  Report is issued at time of inspection.

Level One WETT Inspection

This includes a basic inspection of the solid fuel-burning appliance and venting system components that are visible. It will include measurements of clearances, opening doors or dampers, and a visual inspection of the chimney from the ground. It will identify any noted deficiencies and red flags that may require a more detailed inspection. It will include a final report on WETT inspection forms.

When is a WETT Inspection Required ?

If you have just purchased the property and are unsure about the appliance, you should have this inspection done. If you change your appliance or some of the visible components of the system, you should have the inspection done prior to operation.  Many of my clients are surprised when they change Insurance Companies that they usually get a request to have their appliance Inspected by a WETT Certified Inspector.

Prior to having a Certified WETT Inspector inspect your wood burning appliance  it is recommended that you use our handy guide on How To Prepare for a WETT Inspection