Installing Foam Board Insulation Over Fiberglass Batts In A Floor

Fiberglass insulation is less than half the price of rigid foam insulation when calculated by r value per square foot.

Installing foam board insulation over fiberglass batts in a floor.

I thought there was insulation in that 8 25 space but there isn t. In general the insulation s method of installation can give you an idea of how it compares to other types of insulation. Batt insulation is that pink fiberglass found in exterior walls attic floors and the crawlspace ceiling. It may not happen right away but gravity is patient.

For example insulating a 10 square foot wall area to r 15 costs about 3 40 to 4 00 with fiberglass insulation while a comparable r value for rigid foam costs roughly 10. Foam board insulation is easy to use and is a great diy way to add some insulation. Blown in or loose fill insulation. Whether using loose fill or batts put the vapor barrier closest to the warm side of your.

Even though it s the weakest of the three fundamental forces of nature it s plenty strong enough to pull those batts down over time. Spray foam can be used almost anywhere in the home including exterior walls ceilings floors attics and basements. Fiberglass batts compressed bottom photo pretty much any crawl space with fiberglass batts in the floor above will have the first problem. Some types of thicker foam board insulation are available but they may need to be special ordered.

Roll or batt insulation. This type of insulation typically fiberglass or cellulose insulation can be added over existing insulation provided it s installed. Rigid foam insulation offers a thermal resistance between r 5 and r 8 roughly twice that offered by traditional batt insulation. It comes in standard size 4 8 sheets and smaller sizes in many different thicknesses from 1 4 inch to 2 inches.

Insulation blankets batts and rolls spray foam insulation. Here are the installation methods from lowest to highest average r value per inch. Learn more about spray foam. Install these panels over wall or ceiling cavities including those filled with existing fiberglass batts to boost the r value and improve home comfort and efficiency.

It is made from fiberglass strands that create a barrier for air flow. Though some batts come with a paper or foil facing that can act as a vapor barrier tom silva prefers to use 6 mil polyethylene sheeting cut to fit between the joists and with seams sealed by foil tape to prevent moisture from seeping into insulation.