Working with Fire

SECTION 1211 

Chimneys, Fireplaces and Barbecues

Fireplaces, barbeques, smoke chambers, and fireplace chimneys shall be of solid masonry or reinforced concrete and shall conform to the minumum requirements specified in this code.

A. (6) Corbelling

No masonry chimney shall be corbeled from a wall  more than 150 millimeters nor shall a masonry chimney be corbeled from a wall which is less than 300 millimeters in thickness unless it projects equally on each side of the wall.  In the second storey of a two-storey building of Group A occupancy, corbelling of masonry chimneys on the exterior of the ecnclosing walls may equal the wall thickness.  In every case the corbelling shall not exceed 25 millimeters in projection for each course of brick

Below is a picture from Exallot Building Products, UK that shows corbelling masonry chimney on the exterior of the enclosing walls, The corbelling is equally projected on each side.

 Corbelling

B. (1) Fireplaces and Barbecues

Walls of fireplaces shall not be less than 200 millimeters in thickness.  Walls of fireboxes shall not be less than 250 millimeters in thickness: Except, that where a lining of firebrick is used, such walls shall not be less than 200 millimeters in thickness.  The firebox shall not be less than  500 millimeters in depth.  The maximum thickness of joints in firebrick shall be 10 millimeters.

Fireplace Walls

The above picture from http://thediymommy.com/ed shows firebricks are to line the inner walls of the fireplace. Reinforced concrete is used for the main walls and laid with natural stones as the final finishing touch.

 B. (9) Hearth

Every fireplace shall be provided with a brick, concrete, stone, or other approved non-combustible hearth slab at  least 300 millimeters wider on each side then the fireplace opening and projecting at least 450 millimiters therefrom. This slab  shall not be less than  100 millimeters  thick and shall be supported by a non-combustible material or reinforced  to carry its own  weight and all imposed loads.

Hearths

The picture above shows hearth made out of concrete lined with bricks.  The opening and projecting of the fireplace is about 450-500 millimeters.  It is important to note that only  non-combustible materials are to be used in hearths and chimneys.

Member's name: Caballes, Wendylle