What does R-19 mean and where should it go?

R-19 is the thermal resistance rating. It fits 2x6 exterior wall cavities and some attic and floor applications. It is too thick for 2x4 walls.

Which way should the kraft facing point?

The facing goes toward the warm, conditioned side of the wall. In cold climates that means the interior; in hot, humid climates check local guidance, since a wrong-facing vapor retarder can trap moisture.

How much area does a pack cover?

Each batt is 15 inches by 93 inches, about 9.7 square feet, and a five-pack covers roughly 77.5 square feet. Measure your stud bays and add a little for waste.

Can I use it in a ceiling or attic?

Yes, in attic floors and knee walls where the depth fits and the facing can be covered. Do not leave bare kraft facing exposed in occupied spaces.

Is it safe to install without protective gear?

No. Wear gloves, goggles, long sleeves and a dust mask, and ventilate the area. Fiberglass irritates skin and eyes and the dust is a respiratory irritant.

How does it compare with spray foam?

It costs far less and is simpler for a DIYer, but it does not air-seal. Spray foam insulates and seals in one step, which matters in leaky or damp assemblies.