Air Sealing Around Chimney In Attic

It s usually the hardest place to air seal because the cramped space underneath the eaves where the roof rafters rest on the outer wall makes it hard to move your hands and head.

Air sealing around chimney in attic.

The opening around a furnace or water heater flue is a major source of warm air into the attic photo 5. Expandable foam spray get several cans of expandable foam spray to seal larger gaps 1 4 inch to 3 inches. Put on work gloves. Because the pipe gets hot building codes require 1 in.

When it comes to air sealing it isn t rocket science just ordinary crack sealing. Sealing an air leak around a chimney in the attic 1. Seal fireplace and furnace holes. Caulk gun you need a caulk gun and know how to use it in order to fill air leaks with caulk.

Either work from the interior as walter suggests or temporarily remove the vinyl siding and j channel and work from the exterior. Measure and cut the flashing for each side of the chimney using sheet metal cutters. From masonry chimneys to any combustible material including insulation. So you should certainly seal the air leaks around the chimney at this location by installing metal flashing with sealed seams around the chimney on the underside of the rafters.

Furnace flues require special sealing techniques. Air sealing the wall plate around the perimeter of your attic blocks air from escaping around the outer edges of your home. Because the pipe gets hot building codes usually require 1 inch of clearance from metal lues 2 inches from masonry chimneys to any combustible. Heat resistant caulk use this type of caulk when sealing air leaks around fireplaces chimney and flues.

As you note the chase on the attic floor is not as much of a problem because your basement and your attic are both inside of your thermal envelope. Access the attic through a crawl space in the ceiling using a stepladder or use or the attic stairs. If there s no wood staple it right to the drywall. Furnace flues require special sealing techniques the opening around a furnace or water heater flue or chimney can be a major source of warm air moving in the attic.

For larger holes filler material may be needed. It s easy to overlook electrical wires ducts pipes and vents in the attic but the openings around these are holes can compromise the air sealing of your attic. Because the pipe gets hot building codes usually require 1 inch of clearance from metal flues 2 inches from masonry chimneys to any combustible material including insulation. To seal these openings use caulk or spray foam.

Air sealing the attic perimeter. Of clearance from class b flues 2 in.