Building A Wood Chimney Chase

For chimney chases built into gable walls we install a partial diverter see image 2 again extending the sloped surface several inches beyond the corner see image 3.

Building a wood chimney chase.

Codes allow a maximum of 90 degf temperature rise above ambient inside the the chimney chase well below the combustion or pyrolysis point for plywood. Chimney chase a fireplace chase is essentially a knock out area of structure that hides a metal fireplace or cement blocks in a fireplace. Nfpa 211 reduces fire hazards by ensuring the safe removal of flue gases the proper installation of solid fuel burning appliances and the correct construction and installation of chimneys fireplaces and venting systems. To build a fire retardant chimney chase one might use fire retardant plywood and sure one could try spraying a fire retardant coating but those are not common practices.

Kickout flashings we always install diverter flashings wherever a roof intersects a wall. Common specifications construction details for a wood framed chimney chase dimensions for a wood framed chimney chase may be as small as 24 deep x 36 wide but are more typically 3ft x 5ft x. One solution is to install an insulated and sealed chase and to vent it to the interior so warm air can circulate. Make the chase enclosure airtight chimneys built on an outside wall whether exposed or boxed with a chase are prone to backdrafting.

Called kickouts these keep water from running behind the cladding below and into the wall assembly see images 1 2. Build chase of fireplace just like any other wall structure by placing its uprights between plates and top plates to create a large box.