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0 Answers

Passivhaus Builder certification and BPI Building Analyst certification


I am at the beginning stages of getting my Class A Builder's License in Virginia. Apart from that whole process of getting a contractor's license, I was wondering if getting certified as a Passivhaus Builder or BPI Building Analyst is beneficial not only for expanding my knowledge and creativity, but also from an economic and networking standpoint. Has anyone received new clients or jobs from being listed as Passivhaus or BPI certified? Has anyone gotten hired to a great new job from being certified?

Asked By Jimmy Nguyen | Dec 1 15
13 Answers

Pros and cons of Grace Ice and Water compared to Tyvek Drainwrap

If applying a WRB under rigid foam insulation, what are the pros and cons of using Grace Ice and Water Shield compared to Tyvek Drainwrap, in terms of protecting the sheathing, serving as an air barrier, difficulty of installation, flashing details, and any other reason you might prefer one product over the other to serve as a WRB? Assuming that the Grace product is more expensive, do you believe that it is worth the additional cost on a 2,000 square foot home in Zone 5?

As always, any advice or opinions are greatly appreciated.

Asked By James Timmerberg | Nov 29 15
1 Answer

Do I require a fresh air intake for my fan coil forced air system

I have a Bosch in slab heating system in the basement and the upstairs is heated with a fancoil. Heat is derived from my domestic hot water system which is also heated by the Bosch Boiler. Why would I need, or do I, nedd fresh air to the fan coil?

Asked By Ron Kisko | Dec 1 15
8 Answers

Is there spray-foam insulation without harmful chemicals?

I'm a freelance writer working on an article on insulation, and I was hoping someone might have the most up-to-date info on newer spray foam products that might not pose the chemical concerns of traditional spray insulations (which have reportedly caused many people to develop chemical sensitivities.) Anything out there entirely bio- or mineral-based? (Looks like jury's still out on Airkrete in this forum, and new mushroom-based insulation not readily available. Other suggestions?)

Asked By Susannah Shmurak | Dec 1 15
16 Answers

ZIP R-Sheathing Climate Zone 5?

I am considering ZIP R-sheathing for a home in Climate Zone 5. The wall assembly would be a ventilated rainscreen as follows (exterior to interior)

1. Hardie Panel siding
2. 3/4" furring/airspace
3. ZIP 1.5" R-sheathing (R6.6 total, 12-16 perms for the OSB, <1.0 perm for the polyiso)
4. 2x6 studs
5. Icynene Low Density (5.5" thick R-20, 11 perms)
6. 1/2" gypsum

Asked By Joseph Yount | May 12 15
6 Answers

Heating and finishing a basement in a well-insulated house

Hi Everyone,

3 years ago I built my own house using techniques from this site, and now I need to finish the basement I built for my quadripeligic brother in law who has to move in with us. The basement is a walk out under a gambrel colonial that is highly insulated. The home construction was doing using dual exterior walls and filling the space with a combination of closed cell spray foam and cellulose insulation. I heat my entire 2000sq foot home with two Mitsubishi mini splits.

Asked By Denis | Dec 1 15
7 Answers

Which adhesive for sub-slab vapor barrier seams?

i plan to use 10 mil sheeting on the ground of my lower level, before insulation, radiant, and a new slab.

what kind of tape should i use to tape the seams in the plastic? any recommendations for taping around posts and plumbing is also greatly appreciated.


Asked By Josh | Dec 1 15
1 Answer

Does the underside of fiberglass need to be covered in a flash-and-batt unvented conditioned attic?

I'm renovating my cape cod in Maryland and decided to do an unvented roof assembly since I didn't have good ways of venting the roof valleys and I have ductwork running through the attic, so I wanted a conditioned attic. I should have read the GBA blogs before this project to install rigid foam above the roof sheathing but, in the absence of that wisdom, I'm installing R-15 closed cell spray foam directly to the underside of the roof sheathing and R-30 batts directly under that.

Asked By Mark Stewart | Dec 1 15
5 Answers

Safe to dense-pack cellulose into cathedral ceiling bays and polyiso later when re-roofing?

I have very high and steep cathedral roof in my living room and since that addition was built in '78, it isn't exactly built to some great insulation standards. Rafters are 8" deep and currently I have windswept fiberglass there. Have no idea how bad that kills the insulation value, but looking at how fast temps drop in that room gives me sense it isn't good.

Asked By Apollo | Dec 1 15
4 Answers

New house question

After a lifetime in the Southwest, we are building our first home in a Zone 6 area (Northwest Montana near the Canadian Border). I stumbled across this website accidentally, and have read everything I can regarding insulation/ barrier techniques, but was hoping for some clarification.

Asked By Bill C | Nov 30 15
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