Basements and crawlspace walls are best insulated with rigid foam board insulation. Unlike fiberglass batts, it creates an air and vapor barrier as well as a high R-value.
After the attic, insulating the crawlspace or basement is the next best way to improve comfort and save on your utility bills. Masonry walls have very little ability to resist the flow of heat (R-value). In addition, many basements and crawlspaces are full of air leaks, especially at windows, doors, vents, and around the rim joists and sills that rest upon foundation walls. In an otherwise well-insulated home, heat transfer to the basement can account for up to 30 percent of the home’s energy loss in winter. In summer, a crawlspace or basement that is not air sealed and insulated can raise the humidity levels of your home, making your air conditioning system less effective.
There are two ways to insulate a crawlspace or basement. Insulation can be installed at the exterior foundation walls; or it can be installed under your first level floors, between the joists. But which is the correct way to insulate under your floors?
Dr. Energy Saver Central Virginia can help with these questions. No single solution is correct for every situation. We work with a variety of insulation types, including rigid foam board, spray foam, and cellulose.
There are many options when it comes to underfloor insulation. Dr. Energy Saver Central Virginia can help you choose the best insulation for your home's needs. Contact us today to schedule a free estimate for floor insulation in Central VA. We work in Charlottesville, Fredericksburg, Spotsylvania, Jeffersonton, Earlysville and nearby areas throughout Virginia.
Although fiberglass batts have been stuffed and stapled under the first-level floor in many homes during the past 50 years, its value is questionable. Here are some reasons to avoid it:
Perhaps an even more important reason for not insulating under the floor is that doing so makes the basement a non-conditioned space, often making the basement cold and damp. If you use the basement as a laundry, workshop, or play space, insulating the walls, not the floor overhead, will make it a more comfortable place to be.
Regardless of whether you’re insulating a crawlspace or basement, it’s critical to insulate and air seal the perimeter rim joist cavities with a combination of rigid foam and spray foam.
Crawl spaces may look like short basements, but they are very different. They are awkward to access and difficult to use for anything except storage. Crawl spaces often have dirt floors instead of concrete slabs and rarely have windows; nor are they typically used to house HVAC equipment.
Under-the-floor insulation is common in crawlspaces but subject to the same problems listed above. A better approach is to insulate the crawl space with spray foam or rigid foam insulation.
Spray foam or foam board insulation can be applied to the crawl space walls, and the crawl space floor can be insulated with special foam insulation that's covered with a moisture barrier. Perimeter rim joists are sealed. Airtight hatchways, vent covers, and high-capacity SaniDry dehumidifiers are also available.
There are instances when underfloor insulation makes sense. In cold climates, for example, insulating the floor above the crawlspace is often more energy efficient than insulating foundation walls. Insulating under floors, however, is not always feasible, especially with existing homes. Plumbing, ducts, bridging, and electrical get in the way. Furthermore, the insulation must be able to resist the degrading effects of moisture. You can’t simply stuff the joist bays with fiberglass batts and expect long-term performance.
Sometimes the underside of a floor is open to the outside. A porch or three-season room may have been enclosed but not adequately insulated below. The underside of a cantilevered section of a house is also open to the outside. Or perhaps the uninsulated/underinsulated floor is over an unheated garage. In such cases, there is no choice other than to use underfloor insulation.
We offer insulation solutions for every situation. Whether you are looking to add floor insulation or improve the insulation in your basement, crawl space or garage, Dr. Energy Saver Central Virginia can help! Give us a call at 1-888-370-6924 or get an online quote for underfloor insulation and any of our other energy-saving services.