Morris County Roofers: Article About Vapor Barriers
A vapor diffusion retarder is an essential component of a high performing roofing system. By helping to control the amount of moisture that is able to get into the attic space, these barriers can help extend the lifespan of the roof's wooden sheathing, shingles and fasteners. They also protect insulation and flooring from moisture damage. Homeowners can work with experienced Morris County roofers to find out what type of moisture barrier would best suit their needs.
Class 1 vapor retarding systems include materials such as rubber membranes, glass, sheet metal and polyurethane sheeting. They have ratings of 0.1 perms or less. The most commonly used out of these choices is the polyurethane. It comes in thicknesses of four to six millimeters. Roofers can staple it to the attic's insulation so that the vapor retarder is facing into the attic rather than attaching it to the rafters or wooden sheathing. This class of diffusion barrier is ideal for homes in humid and wet areas. These options can also be used on houses with shallowly pitched rooftops.
Class 2 systems include unfaced or extruded polystyrene foam, 30 pound asphalt covered kraft paper, plywood and bitumen covered kraft paper.
The roofing experts from Peter W Smith Construction of Morris County NJ would be happy to answer any questions you have about roof repair or siding repair.
With moisture protection levels ranging from greater than 0.1 perms and up to 1.0 perms, these materials allow slightly more moisture to enter the house. Roofers will select one of these options for homes located in moderately humid climates. These are also good options for houses with a moderate slope of 3 to 12 up to 7 to 12.
Class 3 vapor retarders have a permeability of greater than 1.0 and up to 10 perms. Roofers will select this material for homes in drier areas of the country or if the rafters are insulated with an open or closed cell sprayed foam insulation. The options for use as diffusion barriers include 15 pound asphalt coated paper. Other materials in this category are not suitable to be used alongside of insulation, but they may be incorporated into the structural components of the home. These other materials include gypsum board, unfaced fiberglass insulation, cellulose insulation, lumber, concrete blocks, bricks and house wrap.
Most homes will be outfitted with a Class 1 or 2 vapor diffusion barrier. Homeowners will typically see the best results if their homes have also been thoroughly air sealed and insulated. These protective measures prevent outdoor humidity from getting inside. Adequate ventilation is also needed, as mechanical venting systems help to dissipate moisture from indoor activities.