Batt Insulation Installation

The three faults we find

Batts perform to label only when they fill the cavity completely, touch the sheathing, and are not compressed. Open up poor batt work and it is nearly always the same three things.

1. Compressed behind wiring instead of split around it. A batt squashed to half its thickness has lost most of its R-value at that point.
2. Gaps at the ends of the bay, top and bottom, where the batt was cut short.
3. Nothing detailed at penetrations — boxes, pipes, the junction with a window frame — so air moves straight past the insulation.

Fixed, batts are an excellent and inexpensive assembly. We friction-fit to the bay, split around services and seal the air barrier at every penetration.

When this is the wrong answer

Not in a closed cavity, which is an injection job, and not directly against masonry in a basement without continuous rigid or closed-cell foam behind them, or you will condense moisture out of sight.

Common questions