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2 Answers

Is makeup air needed for a propane boiler?

We are building a 2200 s.f. house with closed cell insulation and heated with propane radiant heat. The plumber says I don't need makeup air. He says the HRV will handle it and I just need to put a louvered door in the mechanical room. Please advise. Thanks!

Asked By Peter | Sep 28 15
2 Answers

Air sealing & insulating above Mitsubishi ceiling cassettes

Found this response in a related question but wonder if you can illustrate if anyone has an elegant solution for keeping the ceiling cassettes and their awkwardly placed pipes sealed inside the envelope and still making it possible to service from above should it be necessary.

Asked By Mary Quigley | Oct 7 15
1 Answer

If you install a dedicated recirculation line, can you have it run on demand? Or does it have to run continuously?


I'm trying to figure out the benefits/drawbacks of installing a Dedicated Recirculation Line versus an Demand- Initiated Recirculating System. I've already read Martin Holladay's great article in Fine Home Building.

Clearly, the demand-initiated systems are better suited for retrofits since they use the existing cold water line (at least the D'mand one I'm familiar with). And the Dedicated Recirculation Line is better for new construction due to the cost of installing additional plumbing back to the water heater.

Asked By Whitney | Sep 30 15
3 Answers

Insulating a pole barn

Hi. I am interested in building a small (20'x20') eco friendly pole building as a "tiny house". I like the idea of a pole building because it avoids the use of concrete for the foundation. I plan on using perlite bags beneath an earthen floor as the "sub-slab" insulation. For the walls and ceilings, I would like to use cellulose. I have not been able to find any details online for appropriately insulating and air sealing pole buildings. What resources I have found generally ignore thermal bridging entirely, for instance.

I would like to achieve R-40 walls and an R-60 roof.

Asked By Steven Gubkin | Sep 30 15
2 Answers

I live in Iowa and I want to know if it is necessary to have a vapor burrier on my ceiling if I have roof vents

I'm also considering installing an attic exhaust fan, not sure how to determine the size of fan I need.

Asked By Chris | Sep 28 15
1 Answer

Detailing WRB/Roxul/siding in retrofit

I am putting together a plan for a client to add 2" rigid mineral wool as a continuous exterior insulation upgrade. One-story 1974 ranch house, huge 4' overhangs, zone 5 NW Ohio. Existing walls are 2x4 with fiberglass batts and interior poly vapor barrier. Current siding is vertical pine board-and-batten. Already encapsulated crawlspace and insulated foundation walls, air-sealed in attic and blew in more insulation, so doing the walls is Phase 3.

Asked By Andy Chappell-Dick | Sep 30 15
3 Answers

Crawlspace foundation with wing insulation as well as vertical exterior insulation?

Hi. In northern New York state, climate zone 6. Preparing to build a 20 x 30 second home for a client that will be insulated but not heated for the foreseeable future. Some day it might be used year round.

Crawlspace foundation with footings to frost depth. We are planning to insulate the stem walls on the exterior with 2" XPS. A slab is planned at level of footing. We are contemplating skipping the sub-slab insulation of 2" XPS and adding wing horizontal wing insulation instead--in addition to the vertical stem wall insulation.

Asked By Jon Brown | Oct 1 15
1 Answer

Polyiso along ceiling under truss chords

New build in climate zone 5. My plan is to establish my air barrier on the outside with zip sheathing and liquid flashing, and want to continue the air barrier across my ceiling (below a vented attic with blown cellulose). I thought about continuing the zip panels across the ceiling attached under the truss chords and tape them from the inside. I want to have options for drywall and tongue and groove wood for different rooms. I also thought about running polyiso boards in the same manner, maybe in two layers with staggered and taped seams. Any thoughts on this option?

Asked By Brian W | Oct 1 15
11 Answers

Exterior siding layers?

Hello all, I have a quick siding question.

When we spray foamed my shop with close cell spray foam we sprayed against the tyvek(housewrap). It was only one layer. It seemed like the best option we had at the time as I knew I would down the road drop the T-111 osb finished siding and replace it with plywood siding and housewrap and then a cement overlay (making faux stone work out of the cement)

Asked By Max Anthony | Sep 27 15
1 Answer

Attic kneewall insulation

I have a raised heel truss system. The contractor installed wall sheathing up to the bottom of the truss 2x4 as shown in attachments. My overhang is 2' so I will have ~2' of soffit. I will vent according to the sq. footage of my ridge vent (hip roof). I am wondering if it is best to leave these gaps alone, at 3.5" tall or if I should put scraps up and make them closer to 2" tall, or if I should block the ones that will not line up with the vented soffit locations completely.


Asked By Nicholas | Oct 3 15
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