There are 3 types of rigid foam board insulation they are; polystyrene, polyisocyanurate and polyurethane. Each has uses they are better suited for than the others. I will talk about different type's uses and safety measures you should take when installing attic insulation. The first is polystyrene. This type of insulation uses deep heat and pressure to mold into shape. It is best used in walls and installing attic insulation. Although it is more expensive than the other two its characteristics makes it a lot stronger and more durable than the others. The second type of rigid foam insulation is bead board. It is made in such a way that bead expand to fit, producing a better insulated area. This type of insulation is often found in every day products.
Because of the bead spacing moisture is allowed to be absorbed. The third is polyisocyanurate and polyiso foam boards. Because of its strength and durability to withstand extreme temperatures it is ideal when installing attic insulation. It has a wonderful moisture barrier when it's applied with aluminum foil facing. There are some things that you need to know before using rigid foam insulation. First we will discuss flame retarder. This product takes a lot to ignite but once it does it will burn steady. It will also smolder for some time. Safety regulations require you to use flame resistant material like panel, dry wall, or gypsum wall board over the insulation.
It also deteriorates in direct sunlight so if you are installing attic insulation it needs protected with acrylic silicone, rubberized paint asphalt, roofing felt, or tar. Bugs like to make nests in the insulation so if you are insulating basement or floors it is wise to use insecticide treated insulation. Also by placing the insulation on the inside you will discourage bugs. Rigid foam insulation soaks in and traps moisture.
This could easily cause mold and wood damage. To prevent this you should use a vapor diffusion retarder especially when installing attic insulation. Of the three types of insulation; loose fill, batt and blanket and rigid foam board insulation this type has the cheapest initial start up cost. Although it can be used for many things, this product will be counter productive if installed wrong or safety precautions are not correctly taken. Before you begin installing attic insulation please read safety precautions carefully check with local building code regulations.