How To Seal Around Chimney In Attic

Plug the big holes first.

How to seal around chimney in attic.

Sealing an air leak around a chimney in the attic 1. Drop the attic door over the weather. Remove the insulation between the joists where the flue is located to clear an area about 18 inches away from the flue on each side. I installed it upside down with the drop leg pointing up.

Wrap insulation in plastic. 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. Set up a cordless drill with a. Of course you ll still need to seal gaps with fireproof caulk.

Cut a piece of plywood to the size of your attic door. This folded leg strengthens the unsupported edge and created a perfect little trough for firestop caulk. Measure and cut the flashing for each side of the chimney using sheet metal cutters. Install a piece of weather stripping around the access hole in the attic.

Long piece from a batt of unfaced fiberglass insulation and fold it at the bottom of a 13 gallon. 2 many chimney leaks are from cracks in the chimney crown. Apply a thick bead of high temperature caulk the flue on one. You can see that the very purpose of the chimney crown is to keep rain out.

Put on work gloves. Plug open stud cavities. The chimney crown is the cement part on top of the chimney. In places to seal the airspace between the ceiling joists and the chimney as shown in the drawing.

The bricks go up around the tile flue liners but at the top you need something to stop the rain and snow from just falling in around the tiles. The same rules apply to prefabricated metal chimneys. Cut a few pieces of foam board insulation the same size and screw them to the plywood with long 4 screws. Seal around furnace flues.

I used pieces of various widths up to 6 in. Access the attic through a crawl space in the ceiling using a stepladder or use or the attic stairs. The metal and caulk method you describe is one that i typically use in attics but an alternative approach is to frame tightly around the chimney with steel studs then use solid steel channel at the top as a fire block. Finally prepare for adding insulation foam or.