Community: Energy efficiency and durability

Much of the value of this site is the pooled experience of members and their willingness to share it. This page offers a Community area formatted for Questions & Answers dedicated to Energy efficiency and durability. Other topics appear to the right.

Anyone may ask a question and anyone may answer. Sometimes one of our 15 Advisors may chime in; in other cases, you'll get the wisdom of some of our members who have some experience in this area. We encourage everyone to give us the benefit of both their questions and answers. The usual rules of courtesy apply.

1 Answer

8 foot basement walls with 16" above grade

Asked By chris marks | Mar 17 10
12 Answers

Does the big white fluffy stuff have the same R Value as the pink, blown in fiberglass insulation? I have heard it is less affective than R2.8.

Asked By Kellye Markowski | Mar 16 10
4 Answers

I'm interested in ICFs primarily to build foundations for new residential homes. I don't know about using them for the walls of an entire house, but it seems good to use them in foundations, especially as I get more convinced that crawlspace ventilation does not seem necessary in most climates. Building footings with protruding rebar, then stacking ICFs for the rest of the foundation seems so much easier than wood or plywood forming. Then clean and cover the interior earth with ground barrier.....frame without the need for floor insulation, etc.

Asked By Ed Welch | Mar 15 10
8 Answers

After much debate, I've decided that spray foam is not an option I'm willing to explore. Too much room for error. Can I use cellulose on cathedral ceilings? What are my options? I will be making venting channels from the eaves to the ridge and putting something on top of that.

Thanks.

Asked By eggman | Mar 14 10
4 Answers

I have had a silver fish problem in my attic forever and have attempted to rid the problem through use of boric acid to no avail. We are getting ready to do energy efficiency measures in the attic. We are going to air seal and insulate and I was thinking about using blown in cellulose which is laced with boric acid. However, since the boric acid has not worked thus far, am I going to exacerbate the silver fish problem by providing a food source? Does anyone know how to get rid of the pesky creatures? Should I use fiberglass blown in instead?

Asked By Kellye Markowski | Mar 16 10
41 Answers

Many insulation companies in our area have begun to sell hybrid insulation systems. In a standard 2x6 wall, they will spray 1" of closed foam inside the wall cavity and then fill the rest with cellulose. The idea is to get all the benefit of the air sealing, but then to get the rest of the R-value from the much less expensive cellulose. I can foresee many potential building science issues with this, but it's hard to compare to anything out there.

Does anyone have experience with these systems? How do they perform? How is their durability?

Thanks.

Asked By Adam Stenftenagel | Mar 2 09
1 Answer

A mechanical contractor suggests heating a 1,000 sq. ft. 3-bedroom condo with a wall furnace installed in the main room. The heat will be transferred to other rooms by the installation of through-the-wall fans. There will be one thermostat on the furnace. Will this meet any kind of energy code? This is in Massachusetts.

Asked By joe | Mar 13 10
7 Answers

As part of a bathroom remodel I asked the contractor to install a radiant barrier inside the wall behind a radiator. I had envisioned the use of the foil type material, but instead he used a sheet of aluminum flashing. I haven't yet determined whether he left an air gap behind the flashing, but if he did, will the flashing be at all effective? I assume that without the air gap it would be ineffective.

Asked By John Sullivan | Mar 12 10
13 Answers

I am huge advocate of building tight homes. Air leaks, to me, represent poor workmanship that wastes a huge amount of energy. But, just for a minute, I want to be the devil's advocate, primarily because I hear this argument all the time. Tight homes need good, dependable ventilation systems or the occupants will suffer and the durability of the building will suffer......whole house ventilation systems, exhaust fans in bathrooms, hoods, sealed combustion gas appliances, etc.

Asked By Ed Welch | Mar 9 10
4 Answers

We've posted a new video -- an interview with Al Rossetto -- here:
http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/do-it...

In the video, Al discusses walls without thermal bridging, dry foundations, ERV ventilation systems, and radon.

Asked By Martin Holladay | Mar 9 10