Exterior Chimney Chase Construction

Frame the chase so the bottom of the vent is.

Exterior chimney chase construction.

Typically uses 2x4 structural members sheathed with osb or plywood exterior building sheathing. Fire stop at attic and roof deck. Right since the chimney chase carries an insulated metal flue rated for zero clearance possibly actually requiring an inch or more of airspace and because the chase is outside the building it s not normally insulated. But a rot problem would better be blamed on construction or flashing errors that allowed leaks into the chase.

The exterior of the chimney may require tuckpointing or replacement of siding materials to provide the best protection against moisture intrusion into the roof and interior structural materials. Framing the chimney chase. Crickets are more reliable particularly in climates where snow can accumulate and lead to ice dams. Wood siding on chimneys wood shingles are often used as siding material for chimneys continuing from the roof area.

If your home has a wood chimney chase with wood lap siding you need to pay special attention to it. There are a disproportionate number of wood chimneys with rotted siding and wall sheathing when compared to other types of siding and other locations. Keep minimum clearance from pipe to combustibles. Frame the walls on the roof assemble 2 together then stand each set and nail off corners of last two joints.

Chimney chase a fireplace chase is essentially a knock out area of structure that hides a metal fireplace or cement blocks in a fireplace. Build chase of fireplace just like any other wall structure by placing its uprights between plates and top plates to create a large box.