The Perfect Wall (wonkish)

I've adopted the (wonkish) tag from one of my favorite writers. I'll leave it to you to figure out who it is since he doesn't write about home design and it would be way off track to mention here. A different favorite writer, one who does write about home design although in a very technical way  is Joe Lstiburek of Building Sciences Corporation. I highly recommend that you visit the BSC site if you're interested in technical analysis of building performance issues. Anyway....this is a great article (in Joe's inimitable style) that helps to clarify the complicated interaction of  moisture, air, and heat.

Dam Ice dams

I have had many calls and emails from clients over the past few weeks asking me what to do about the ice dams on their roofs. The most comforting words I have are "you're not alone". Joe Lstiburek at BSC talks about the ice dams and icicles we see everywhere these days (thanks Dave). This articles says about everything there is to be said about the problem. There is no quick fix. Scraping the snow off the roof just damages it, the underlying problem is always lack of air sealing and insulation.

Calvert USA, Attic stairs

Calvert Attic stairs

Pull down attic stairs are a necessary but awkward and badly insulated part of many houses. We often try to seal and insulate old attic stairs. The results are usually unsatisfactory. If you are replacing a pull down stair, the ones they carry at your local big box store are only of one or two sizes, not weatherstripped or insulated, and have a rickety mechanism that verges on dangerous to use. This company produces the best, most versatile attic stairs that I have found. Many sizes, many heights, a robust mechanism, aluminum and steel ladders as well as wood. They fit flush with the ceiling and are easy to trim inconspicously. Best of all, they come with excellent weatherstripping and integral insulation up to R-14. They also have horizontal mounting stairs for hatchways in gable ends. What more could you ask for?

Horizontal mounting stairs

Warning: For Energy Nerds- Wall Energy Rating

All of us in the energy efficiency business know that building assemblies depending on fiberglass for insulating value almost never function at the nominal R value theoretically obtainable by a given thickness of fiberglass. We see a lot of attics with 5-1/2" fiberglass batts bearing a stamp on the label of R-19 that in fact function at R-5 or less. If you've never seen the BPI guidelines for the value of existing insulation, you might be surprised. (At least in an attic you can improve the situation pretty easily with blown-in cellulose.) But how about an existing stud wall? There's no room for any more insulation. Canadian building scientists are trying to develop a new thermal rating system for walls called, appropriately enough, wall energy rating. The purpose of this rating is to more realistically reflect the thermal resistance of wall assemblies subject to air infiltration.