Fixing a draft / fireplace doghouse/kickout

dkizerian · 03-08-2012, 01:20 PM

Hi, I'm having an issue with my new house, and I'm doing some research to make sure the builder isn't just going to put a bandaid on the problem.

During a recent snow storm which included some decent south winds my wife and I noticed a draft in the 2nd floor master bathroom, coming from below the baseboard on the north facing exterior wall. we didn't feel any draft in the master bedroom which shares the same exterior wall. The next morning we also noticed that the tile floor in the master bathroom was SUPER cold, we even compared it to the other two rooms upstairs that have tile, and it was very noticeable.

I have a large doghouse/kick-out on the first floor that houses a gas fireplace, and a TV nook. This is directly below the master bath, and the roof of this structure ends up being just above floor height for the second floor. The soffit on this small roof is vented, which worries me, as there is no top vent

I poked and prodded around that morning, and found that the interior side walls of the TV nook were also ICE cold, as was the small beam over the nook. The bottom, top and back were cool to the touch. All surfaces that are part of the kick-out were cooler than the house's exterior walls. Also noticed some draft coming out of the electrical sockets in the nook and the two a/v wiring boxes as well.

Image of it when just drywalled. Unfortunately it's done now, so work will be harder.

What would be the correct way/s to have this doghouse insulated? Where should there be vapor/moisture barrier? How should the roof of this thing be sealed? and are there any other things I should look for as we dig into getting this repaired?

Here is an interior picture before the drywall or insulation

Thank You
Dave

jklingel · 03-09-2012, 02:24 AM

Your electrical boxes don't look like they are made for air sealing (I don't see any lip on them to goo or gasket; is there one?) so maybe no attention was given to air sealing. All exterior walls should be insulated to code; R value depends on your area, but since I see snow it looks like you need R19 or more. Too, the insulation needs to be installed meticulously, esp w/ all those odd widths you have there. Were your corners insulated? Sometimes those get skipped because it is hard to get into them, and folks don't sometimes insulate them before they are built. Is there any foam on the exterior? Was seal sealer of some kind (gaskets and/or goo) installed under the bottom wall plates, etc? As for a vapor barrier, you likely don't need/want one. You should, however, have good air sealing somehow. Ask your builder what was done in that regard. You also have a God-awful lot of wood in places, which displaces any insulation. Drafts in new homes are inexcusable. Sorry if I can't answer any questions, but maybe you have more questions for the builder now. Good luck.

Windows on Wash · 03-10-2012, 12:11 PM

At least they didn't use a vented soffit on that overhang like they normally do.

Caulk and seal all the exterior joints in the siding, fascia, rake, and soffit connection.

Drop the floor of the box and plan on getting up inside that chase.

Spray foam and seal all the boxes between the drywall and the living space.

Use intumescent sealant between the flue and the exterior wall.

Spray foam and seal all the connections to the home but keep the spray foam away from the flue and the back of the insert.

Back the whole area with Roxul and insulate the entire thing.

Seal up the floor and put the box back up.

**Gary in WA** · 03-10-2012, 11:01 PM

The siding should already be caulked, don't caulk any siding laps. The cavity ceiling should have been fire-blocked behind the horizontal frame making the ceiling in there. And caulked to stop air from entering at the roof soffits and mitigating down the exterior walls, fiberglass insulation will not stop air movement. The wall cavities above the floor level on the exterior walls of rooms above should have been sealed from the soffit vents. The shed roof should have been air-sealed from the house/any other areas, to vent at the side-wall/shed roof joint: http://www.dciproducts.com/html/smartvent.htm This would form it's own little attic, air-sealed from all else, even framing below the roof, and especially that joint of shed/house. I see (in the picture) there is no fire-blocking (required per code) behind the sides of the ceiling framing to stop any fire from below of reaching the shed attic/your wall cavities next to bathroom above.

It's already done.......... wrong.

Gary