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1 Answer

Unfaced XPS vs Foil-faced Polyiso for Rim Joists

Hi all

I'm looking to insulate my basement rim joists in the next few weeks, getting rid of the stuffed in fiberglass batts. I've done some research here and other places, and I'm kind of stuck trying to decide on material to use. Based on cost and material availability, I've narrowed it down to using 2" unfaced XPS or 2" foil-faced polyiso.

In General questions | Asked By Paul Jones | Aug 21 16
5 Answers

Mineral wool roof

We are in the beginning design phase of our new house. The current concept is a 1,600 sqft ranch with a 4/12 pitch shed roof to allow clerestory windows along the south side. We are in the middle of Iowa, on the edge between climate zone 5 and 6.

The single roof plane would be a cathedral roof with both interior and exterior insulation. No valleys, no skylights, no dormers, no can lights, just a single roof plane with fascia mounted vents at the top and bottom.

In Energy efficiency and durability | Asked By Ben Woline | Jun 3 16
3 Answers

Central Fan vs. HRV

Hi all another question.

Background: I live in Minnesota (6B on the climate map) and I have a 3 year old house with bath fan exhaust only. There are 3 bath fans on the second floor that run constantly. House is about 3800 sqft now and will be almost 5000 sqft when basement is finished. We have been running the furnace fan constantly recently to keep the house even in comfort, I'm experimenting with "circulate" vs. always-on. Furnace is high efficiency but with an old school motor, not ECM. I don't see us proactively changing the furnace in the near term.

In Mechanicals | Asked By Ben H | Aug 20 16
1 Answer

Sub slab insulation and radon


I am building a new home in Syracuse NY. The home will potentially will require a radon remediation system. I was also contemplating doing rigid foam insulation underneath the basement slab - there will be living space in the basement.

What, if any impact on radon seepage into the home would subslab insulation have? Might it help prevent that seepage? Or could it make it more difficult to remediate if i do have a problem? Thanks

In General questions | Asked By david schreiber | Aug 21 16
2 Answers

Subfloor insulation at 8,500 feet in Colorado?

I'm building a studio/shed on our property. Using local rock under the beam supports, basic plywood construction. Wondered what the most efficient and simple insulation should be between the joists and under the subfloor?

My research has yielded A LOT of varying opinions and recommendations. Spray on... Polyiso boards... etc.

Love to get some suggestions from folks at GBA.


In General questions | Asked By Eric K | Aug 20 16
6 Answers

Basement insulation questions

I've read through a ton of posts here on GBA and I want to thank the community in advance.

I'm finishing an unfinished basement in Parker, Colorado and I'm performing the following items firs from an insulation standpoint.

My basement is a structural basement floor which is a steel beams based with OSB on top and there no no slab in the basement. It looks very similar to this.


In General questions | Asked By Joseph Brooke | Aug 18 16
8 Answers

How far will a ductless minisplit throw heat/cool?

Assuming an open area with a good line of site, what can you expect a ductless mini split to throw heat/cool. For example, if you have an open, but large floorplan, could you put a mini split on one outside wall and have it throw heat/cool to the other wall which is, say, 40' away? What about 50'?

In Green products and materials | Asked By Clay Whitenack | Aug 15 16
4 Answers

Durability problems: Keeping paint on an historic house?

Our local historical society maintains an 1843 farmhouse as a museum. For the last fifteen years it has been unoccupied, except for occasional guided tours (monthly?) and two big day-long festivals annually.

Exterior paint lasts only a few years, and the society has asked me for suggestions on steps to take that might prevent paint from peeling so quickly. Anybody on this forum ever worked with something like this? I assume there's a vapor problem, or worse.

In Energy efficiency and durability | Asked By Andy Chappell-Dick | Aug 19 16
2 Answers

ERV with dual ECM motors and good controls

Is there anything else besides Zehnder (a bit pricy, but quality supposed to be great) and Recouperator (looks dated and also pricy considering accessories) on the ERV market that would fill below requirements:

1. 2 ECM motors.
2. Economizer or free summer cooling (assuming humidity levels are not crazy)
3. Being able to set it to slight positive pressure (and ramped up speed to get to it while using clothes dryer and wood burning stove)
4. Controls good enough to do #2 and #3, optionally in conjunction with existing 3 zone Prestige IAQ and HZ432 ran system.

In Mechanicals | Asked By Nick Zees | Aug 12 16
2 Answers

Moving from exhaust-only to an HRV - outside venting question

Hi all, appreciate any help you can give.

I live in Minnesota (6B on the climate map) and I have a 3 year old house with bath fan exhaust only. There are 3 bath fans on the second floor that run constantly. House is about 3800 sqft now and will be almost 5000 sqft when basement is finished.

I'm thinking about switching to a HRV while the basement drywall is still open and shutting down the bath fans. In mechanical room HVAC is high efficiency so plumbed intake and exhaust. There is a 6 inch flex fresh air in the mechanical room seemingly just for the water heater.

In Mechanicals | Asked By Ben H | Aug 19 16
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