Crawl Space Foundations Are

Return air leaks cause negative crawl space pressure, increasing the rate of soil moisture evaporation and soil gas migration.5. Seal the CleanSpace to the foundation wall by using construction adhesive. Downspouts should empty 8 to 10 feet from the foundation2. Install gutters and slope grade away from the foundation at least 5 %( 6 inches per 10 feet) to direct rain and surface water away from the house. Extend the outside edge of the CleanSpace up the foundation wall to a few inches below the top plate. However, extensive field experience indicates that it does provide exceptional environmental control for a safe and healthy crawl space environment. rain water, underground springs) must be eliminated. Cover the crawl space with a 20 mil polyethylene vapor barrier called CleanSpace. Because this foundation technique is utilized in a relatively small number of new homes, it is prudent to talk to your local county or city code official before construction. Outside foundation walls are insulated using code approved rigid insulation with flame spread less than 25. Rainwater is controlled by gutters and downspouts, as well as a 5% grade sloping away from building. CleanSpace crawl space access doors can also be used. Overlap all seams and seal with CleanSpace vapour bond tape tape. The durable CleanSpace vapor barrier covers the foundation wall and terminates under the sill plate (or lower if retro fitting). These foundation types are equipped with operable vents designed to provide ventilation for moisture control. Because outside ventilation has been eliminated, under no circumstances should combustion products, such a lawnmowers, gasoline, paints or solvents be stored in the crawl space. A dampered duct attached to the forced air heating/air conditioning system or a small exhaust fan transferring air from the house provides conditioned/ house air to the crawl space. The code also allows for the installation of an exhaust fan to exhaust crawl space air to the outside.6. This technique is not in full compliance with local and national building codes and should not be specified for new construction. Outlined below are techniques for unvented and conditioned crawlspace construction. Before any efforts are made to control ground or air born moisture, all bulk moisture entering the crawlspace (i. Close and seal all foundation vents with CleanSpace vent covers or spray foam cavity to eliminate warm, moist outdoor air from entering the crawl space. If outside grade is higher than inside grade, a damp proof coating on the exterior foundation wall is recommended. Additionally, high humidity provides an ideal environment for insect growth.3. In either case, the band joist is insulated using either rigid or batt insulation. Unfortunately, venting a crawl space during air conditioning season allows for the migration of hot, humid outside air into the cooler environment inside the crawl space. Outdoor air is controlled by sealing all penetrations to the exterior and installing gaskets around access doors. Temperature stability makes crawlspaces an excellent location for air conditioning equipment, ductwork and plumbing, however; high crawl space humidity during summer months may lead to condensation on ductwork and equipment damage.Unvented Crawl SpaceUnvented crawl space retrofits are usually.