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33 Answers

Spray foam insulating

I have a home that is approx 800 sq ft in size not counting the attic.
I'd like to spray foam it.
It is about 70 years old built with 2x4's.
Crawl space, no bsmt.
A little over 8' walls on main floor ( 100")
I was planning on doing 3" of closed cell 2LB spray foam from a professional.
Also, as well in the rafters since it is a sloped roof but I'd like the attic finished since it is 7ft high, I would have some nice, temp regulated storage and I am planning to install the furnace there too.

I was then made aware of certain concerns.

In GBA Pro help | Asked By mic l | Apr 16 16
19 Answers

What about ducting "make-up" and direct exhaust air through an HRV core/box?

It is clear that an HRV is not for providing "make-up" air, but do any suppliers sell the HRV unit with/out motors so that spot specific venting that I'm planing to direct-vent to the outdoors can be ran through an HRV box with the make-up air coming in to temper that cold air?

In Energy efficiency and durability | Asked By eric Mikkelsen | Apr 15 16
8 Answers

Humidity inspectors

Would anyone know of a company that locates the source of humidity in the home? I have been having so much trouble getting Sears to replace the water heater they installed at the end of last year. They keep demanding statements from inspectors to prove that the humidity in my guest house is actually being caused by the water heater! There was no humidity beforehand. Now there is condensation build-up on the windows, which drips down and causes mold to grow on the window sills.

In General questions | Asked By Lea Eigard | Apr 15 16
8 Answers

Reasons NOT to use Fibertec Windows for your Home

Per a phone call 4/15/15 from Fibertec, they have expressed concerns that my original posting unfairly places them in a negative light. To avoid the potential option of Fibertec taking legal action for perceived damages, I am temporarily removing this post so that I can discuss Fibertec's concerns with them and substantiate my claims in greater detail for their awareness. Once completed (shortly) I will repost my thread with any potential corrections.

In Energy efficiency and durability | Asked By Darin Anderson | Mar 31 15
81 Answers

Bathroom/laundry vents through HRV?

We are building a super insulated house. I've been a carpenter long enough and studied enough that I'm confidant the envelope will be tight.

The thing I am least comfortable designing is the ventilation system. I am planning a balanced, ducted system, with the HRV acting as the air handler. Simple enough to balance if the system includes only fresh and exhaust air, but what about bath and laundry area fans? Do you run those through the HRV as well?

And what about the kitchen range vent? If these DON'T run through the HRV, where does their make up air come from? Passive vents?

In General questions | Asked By jim blodgett | Jul 5 09
2 Answers

I have an ICF foundation with a 1x at ground and below grade that is pulling away from the foam form

I have an ICF foundation with a 1x at ground and below grade that is pulling away from the Foam form. How do I correct?

Debris has gotten between the wood application and the foam form. Is this a problem to the integrity or simply a cosmetic problem? What is the best way to repair or replace?

In General questions | Asked By Al Bedard | Apr 16 16
2 Answers

Material for thin profile wall sheathing air barrier behind tub ?

Looking at a couple of GBA detail files:


New house addition will have tub and shower on exterior wall; there will be no pipe or wire penetrations in the wall. Wall construction outside-> inside is:

fiber cement siding
3/4 strapping (rainscreen)
2" Roxul Comfortboard
#15 asphalt felt
5/8 plywood, all joints taped with Siga Wigluv
2x6 studs
5-1/2" Roxul batt

In Green building techniques | Asked By Michael Tuso | Apr 16 16
9 Answers

How high a percentage of glass (sq. ft.) before radiant floors become a reasonable option?

In 1998, we purchased a house in NY right on the border between climate zone 5 and 6. It was dark.... I mean, really really dark inside and out. The house was 1.5 stories and about 1500sqft with a large room in the front with a high cathedral ceiling. Limited windows, large 2-car garage taking up the southwest corner.

In Energy efficiency and durability | Asked By Nathaniel Hieter | Apr 15 16
16 Answers

Radiant heat design details - Bosch or Navien combi boiler?

I am getting into the details of our radiant and DHW design and was looking for some feedback on the boiler choice. I have been planning on using a combi boiler and so far favored a Bosch model, but have started to wonder whether the Bosch would short cycle in my planned setup.

These are the two Combi Boilers that I am considering:

  1. Bosch Greenstar 100
In Mechanicals | Asked By Torsten Budesheim | Apr 13 16
24 Answers

Is it possible to have too many air intake vents in house?

Is it possible to have too many return Air vents in house? Of course I guess anything is possible.
But I believe it was someone on this site, that responded to an issue I have with a Lennar home.. IT was build as part of their "green' series. I lived in the house for 9 months and after my second trip to the emergency room due to air quality or lack there of in the house... I moved out... And I have been trying for 2 years to fix it.

In Green building techniques | Asked By Barry Ross | Apr 12 16
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