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10 Answers

High humidity in between floor space in 2-story home in Zone 3A

Our home has a "crawl" space in between the first floor and second floor, all of our AC duct which is insulated is in this area. It appear to be well insulated, and is the same temperature as the house most of this time, within 1 degree or 2.

The issue is the humidity in this area is 30% higher than inside the house most of the time. The humidity in the house can be as high 58% in this humid season right now, but in the crawl space it is as high 89-90%. It seems like it should not be this different?

Asked By Momndad | Aug 18 17
2 Answers

Crawlspace with Cellulose Insulation - Go or No Go ?

Greetings GBA folks,

From Columbia SC. Please help determine whether blown in Cellulose between the floor joists is recommended.

Here are the parameters measured in the 20 year old crawlspace:

1. Current moisture content of the joists is at 18 %
2. Relative humidity is at 72%
3. Foundation is drained professionally well down to the footers - no current issue with water, or termites
3. Crawlspace is awaiting contractor to install 20mil vapor barrier to 1400 sqft dirt floor area

Asked By FusionHome | Aug 20 17
10 Answers

Surface-mounted LEDs

I understand how recessed lights are a problem with air sealing, so I want to go with surface mounted LEDs wherever I can. So, how are these mounted and wired? Is a 4" box sealed with foam and then the box sealed to the ceiling, followed by the surface mount?

Also, are there any smart LED fixtures that work with Google Home?



Asked By Norman Bunn | Aug 16 17
0 Answers

Ductless Mini - Dehumidification Mode - Power usage?

On a Mitsubishi ductless mini split, when in dehumidification mode, how much power does it draw? Would it draw less or more power than when in cooling mode?

Asked By Peter L | Aug 20 17
1 Answer

Why does GBA promote PHIUS a opposed to the Passivhaus Institut?

You say the PassivHaus Institute is in Germany. No such organization exists. The least you could do is accurately spell the name of the organization you reference. The Passivhaus Institut who coined the term "Passivhaus" and established the global "passive house" standard in or around 1990 exists in Germany. You then draw a direct comparison by falsely stating that "we have a branch here in North America called..."PHIUS." Who is "we?" What authority associated with the Passivhaus Institut gives you authority to claim that you have a branch here in North America????

Asked By Michael R Conners | Aug 20 17
6 Answers

3/12 pitch roof insulation

Hi all.
I sent a question and got a reply on a 2/12 pitch roof.

I have an architect working on my plans now. It is a single-slope roof at the widest part (of 32 or so feet).

I originally was going with 3/12 pitch, but he thought 2/12 would be a lower roof at the tall end, so I said fine!

Now, looking at the problems with 2/12, I asked to go back to the 3/12 pitch. So: If I go 3/12, would I (or should I) use R-60 fiberglass? It will have 24 in. parallel trusses.

Would I still need a cupola? (Zone 6, lower Michigan.)

This is TMI for my small brain...


Asked By Robertsoave | Aug 19 17
1 Answer

flat roof membrane types

Hi All,

I'm looking for advice on the best type of flat roof membrane. I'm currently getting estimates to have a new one put on, with estimates for TPO, EPDM, and fibertite. The roof has ponding issues so I'm also going to have that corrected with tapered foam insulation. I live in zone 6A. Thanks for your insights!

Asked By Tina D | Aug 20 17
5 Answers

Wall Assembly

Below is a wall assembly of one builder we've looked for the purpose of doing the framing, windows/door installation and the various barriers (WRB, Vapor and Air). I wanted to know everyone's thought are for my climate in Ottawa, Canada.

My opinion is I don't think this is a good wall assembly for the following reason:

Asked By Arnold K | Aug 19 17
0 Answers

I would appreciate a review of an air-source heat pump quote

zone 7 Kenora Ontario, Canada.

I asked for a quote for an ASHP unit that would work for the time being as well as in the near future when the house is expanded...

Some background....

1-short term.. (with the building as is)

-to heat and cool my existing home, 850 sq ft 2x6 framed 20 yr old bungalow on conditioned 5 ft insulated crawlspace...

I completed an online manual J about a year ago and determined as best I could a heat load of about 25000 btu.


Asked By Tim Brown | Aug 19 17
14 Answers

Renovation to address heat gain (summer), heat loss (winter) and ice dams

We have a home at about 6000 feet elevation in Utah. It’s dry, and the temperatures can vary from below zero F in winter to over 100 F in summer. Our house was built in 1994 with some attic space and lots of cathedral ceilings. From what I have observed, the roof/attic was not insulated well when built. This has been partly remedied by blowing in extra insulation into the attic, but most of the cathedral ceilings where framed with 2”x12” with probably 8” or 9” thick batts of fiberglass. In short, the roof has lots of heat gain during the summer and lots of heat loss in winter.

Asked By Chris Butson | Aug 13 17
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