Insulation, Radiant and Vapor Barriers - Insulation Question

What's the difference between roll insulation and batt insulation? I saw an ad in the paper about a roll of insulation (R-13) being about $6.96. It was 40 sq ft. Then I saw a person could buy 11 batts of R-13 - 106 sq ft for about $23.96. I'm just wondering how to compare the two.

Thanks!

The batts come in 8 ft. long pieces. This is good if you have a standard room with 8 ft. high ceilings. The roll comes in one long piece, which means you have to cut the insulation to length. This is good if you have 9, 10, 11 or 12 ft. ceilings.

Thanks for your quick response.

What is the best way to cut insulation?

First measure the length of the wall cavity. To cut the roll insulation, you will need the following.

1. At least a 20 inch by 20 inch piece of plywood to protect the floor.

2. A 2 x 4 at least 20 inches long.

3. Tape measure and utility knife with extra blades.

Lay the plywood on the floor and roll the insulation over the plywood. Measure the length of the insulation you want and move either the plywood or insulation over the plywood to that measurement.

Lay the 2 x 4 over the insulation with the plywood underneath with one edge of the 2 x 4 on the measurement you made. Kneel on the 2 x 4 to compress the insulation and take your utility knife and cut along the edge of the 2 x 4 to cut the insulation. Before you get up from the 2 x 4 make sure the insulation separates. If not, make another pass with your utility knife.

i don't highly recommend using just fibre glass, specially if you have all soffit vents because of wind washing, this is when the air travels through the pink or yellow filter insulation (as we call it) it loses the R-value because the wind makes the top and bottom of the insulation the same temp as outside so your R-13 goes down to about R-5