How To Seal Chimney In Attic

After the air sealing work was complete including wiring vent and plumbing penetrations throughout the attic the attic received an r 60 blanket of blown cellulose insulation.

How to seal chimney in attic. In places to seal the airspace between the ceiling joists and the chimney as shown in the drawing. Access the attic through a crawl space in the ceiling using a stepladder or use or the attic stairs. Set up a cordless drill with a. 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.

Then finish up by sealing the access hatch with self sticking foam weatherstrip photos 10 and 11. I used pieces of various widths up to 6 in. Measure and cut the flashing for each side of the chimney using sheet metal cutters. Sealing an air leak around a chimney in the attic 1.

Now pour the water repellent sealer into the low pressure sprayer and spray it evenly all over the chimney. I installed it upside down with the drop leg pointing up. You have to start from the bottom and spray the sealant on the bricks evenly. Some of the repellents will drip down.

That material is not allowed to contact the masonry chimney so after blocking the bypass jerome fit pieces of 2 inch roxul mineral wool insulation around the chimney to isolate the masonry from the cellulose. Remember that all chimney flashings need to be masked off prior to applying the sealer. Put on work gloves. When you re done sealing your attic bypasses push the insulation back into place with an old broom handle or stick as you back out of the attic.