Ways to help insulate during framing

The framers have pretty much finished the first floor walls and will start sheathing the outside walls with OSB tomorrow. Here's a good place to mention a few easy jobs that can be done during framing that will reduce drafts and air leakage. Insulation alone won't solve these problems later on.

Starting at the bottom, or sill plate, where the wood meets the concrete foundation. There is a gap between the wood and concrete which needs to be filled with either caulk or sill sealer. This eliminates any draft from penetrating. The gap is too small for insulation to work. Too many times I see this low cost step omitted in the framing process.

Then there is what I call the T-wall intersection, where an inside wall butts up against an exterior wall. Left alone, this 4" cavity will get sheathed over on the outside and then there is no way to put insulation in this area. So I decided to buy some "Great Stuff" in a can and foam it up before the sheathing goes on.

Finally, my headers are double 2x10s. Typically a 1/2" OSB is sandwiched in between the two boards. This has no added structural value but instead is just used to bring the inside and outside of the header in line with the 2x4 walls. Here's the math: a 2x10 is actually 1-1/2 inches thick. Times two is only 3 inches. That's a half inch shy of a 2x4 wall which is actually 3-1/2 inches thick. Hence the need for the 1/2 OSB spacer. The problem is that this header become a conduit for cold air to migrate through the wall. In other words, there is a cold spot on the wall wherever the headers are used on the outside wall. To make an extremely long story short, you should use 1/2 inch rigid foam insulation in place of the 1/2 OSB material. Minor additional cost.

Floor trusses are delivered tomorrow. These will be open web trusses. They are green in that they use less wood. Short scraps of 2x lumber are used to build the trusses. Plus, my air conditioning ducts, plumbing and electrical can easily be run through them.