Foam Insulation - Especially As A Best Practice!

Something I don't see often on new construction is foam insulation - especially as a Best Practice!

In contrast to yesterday's post, where new construction had entire exterior wall gaps that would not have received insulation, this house has its rim joist sealed against air passage, with insulation put on top of that.

This is so good to see!

I am hoping that this is the new wave in home construction around here.

Our area is one that experiences very low AND very high seasonal temperatures.

Rim joists are an area through which huge amounts of air, hot and cold, can pass.

This affects every aspect of the environment inside of a house.

Yes, a house needs to breathe, it is true.

But such respiration must be done properly and controlled so that it does not contribute to moisture build up or microbial growth.

Notice what is being done here.

All exterior wood material, called the rim joist or frieze board, is coated with an open-cell foam, probably some form of Icynene.

It surrounds the bathroom vent tubing as well as the lines from the AC compressor.

It can be seen puffing out.

The top photo shows that the rim joist along an entire exterior wall is coated with the foam also, in dramatic contrast to yesterday's post.

On top of the foam everywhere is regular fiberglass insulation.

The foam provides an R-value of about 3 per inch.  But the real benefit is that it completely controls air flow.  This is a real advantage when fiberglass is used in addition.

The fiberglass is there to add a bit of additional thermal barrier.  More insulation is almost never a bad thing.

The other green color seen is a copper solution sprayed here on exterior wood in lower levels, especially when there are basements.  It acts as an insect and moisture repellent, as well as a fungistat.

All in all I consider this to be

Best Practice

And it was very nice to see!  And I expressed my enjoyment many times to my client and his agent, AR's Karen Kruschka.

My recommendation:  when you see something that looks different or outside the normal, bring it up with the construction supervisor or home inspector.  See what the house is offering!  You might be pleasantly surprised!