Installing Foam Board Insulation In A New Or Existing Structure
Foam boards consist of rigid panels of various types of foam including polystyrene, polyurethane, or polyisocyanurate (polyiso). Many of these materials can be toxic if not handled carefully. The excellent insulation properties of the various foam materials in use today make them a popular choice when Types of foam board insulation include:
• Molded Expanded Polystyrene (MEPS) is described as a closed cell material which is molded in to everyday items like shipping materials and even coffee cups. It is also formed in large sheets used for foam board insulation. It is also known as bead board.
• Extruded Expanded form of Polystyrene Foam Boards (XEPS) is another closed cell type foam material primarily used in insulating buildings. Polystyrene pellets, mixed with various chemicals, turn into a liquid state then are injected into forms where they harden upon drying.
• Polyurethane and Polysocyanuate (polyiso) are another similar material formed from closed type cell foam insulation materials. They all have a high R value (R 5.6 up to R 8) for each inch in thickness. This allows the installer to use thinner boards to achieve the correct amount of thermal resistance when installing foam board insulation.
Unless you have experience with installing this form of insulation, it is best to leave it up to a professional installer. If this is a basement wall insulation installation, you will need to make sure both the exterior and interior walls are free from cracks or holes. Also be sure there is plenty of basement ventilation to avoid mold spores and their accompanying smell.
If installing foam board insulation is to be done in the attic, make sure there is plenty of attic stairs insulation and when insulating an attic be sure the opening, walls, and the stairs are insulated as well.
It is important that all types of insulation foam be protected from direct sunlight. Ultraviolet rays from the sun can, over time, damage the insulation. A coating of acrylic, tar, rubberized paint, or even silicone can protect the foam. Also applying a plastic or rubber membrane or layering of asphalt then applying roofing felt can protect it.
When the air inside a building is warm and it’s cold outside, there will be a build up of water vapor which may penetrate the wall’s finish and enter the insulation. This will then condense giving rise to mold and mold spores building up and the surrounding wood may well begin to rot.
While insects do not eat the foam boards, they may tunnel through easily and enter the house. It is a good idea (and a law in many building jurisdictions) to treat the ground surrounding the structure with an insecticide.
While foam insulation will rarely ignite, exposure to flames will create a dense smoke which contains many toxic gases. Many building codes require a fire barrier, usually consisting of gypsum wall board be used as a fire barrier.
