If you're looking to add more livable space to your home, there may not be a need to build an extension; and if you're having this thought while standing in your kitchen, the extra livable space you're looking for is probably right beneath your feet: in the basement.
According to the National Association of Homebuilders, over 68 percent of homes across the U.S. have a basement, and this space doesn't have to be the dingy, dimly lit, spider-web covered area just used for additional storage. Creating a finished basement opens up the possibility of adding extra living space — a man cave, play room, home theater, or bedroom; not only does this benefit the homeowner, but presents a huge opportunity for contractors to capitalize on.
By simply installing insulation and air sealing solutions in key areas of the basement, a professional or homeowner can easily create a comfortable environment that will increase the home's living space and most likely increase the home's value.
Key areas homeowners and contractors should consider when creating a finished basement include: the interior of the basement wall, rim joist, and crawl space. Let's take a look at solutions for each of these three areas to create a comfortable space in the basement.
Interior basement wall
A major component of creating a livable environment in the basement is to ensure it is properly insulated. Rigid foam insulation over masonry or concrete basement walls, helps increase the energy efficiency of both new and older homes, and provides long-term thermal performance to warm the basement wall while also providing moisture-resistance to help prevent that "damp basement" feeling.
As a quick, easy, and energy efficient solution that satisfies both insulation and aesthetic needs, Dow offers THERMAX White Finish Insulation. THERMAX™ White Finish Insulation has a high insulating value (R-value of 6.5 at one inch thick) and features an embossed white acrylic-coated aluminum facer on its exposed surface for a clean, finished wall appearance that is both durable and washable. THERMAX foil faced sheathing can also be left exposed in areas where a finished look is not critical.
For a fully finished option in areas where drywall will be installed, STYROFOAM™ Brand WALLMATE™ Insulation is designed as a quick, easy-to-install and durable option for insulating interior basement walls and other areas of the home. When butted together, the edges form a slot between the extruded polystyrene foam boards to accommodate a wood nailing strip, which is used for attaching the boards to the basement wall or ceiling rafters. It also provides a nail base for drywall.
The rim joist (where the basement wall meets the underside of the first floor) is a significant source of air infiltration and potential energy loss in the home. There are two ways to air seal and insulate this area. The preferred method is for a professional contractor to apply FROTH-PAK™ Foam Insulation, a Class A spray foam that comes in an easy-to-use portable kit. When using this method, make sure the foam seals all the way from the rim joist to the top of the basement wall.
A quick and easy alternative to using FROTH-PAK™ Foam Insulation, that both experienced DIYers and professionals can do, is to install a piece of rigid foam insulation board in the space and "picture frame" around it using a one component insulating foam sealant such as GREAT STUFF™ or GREAT STUFF PRO™. Just cut a piece of insulation board to fit, then seal around the perimeter to secure it in place and block air infiltration around the edges. Make sure to seal the seam between the sill plate (bottom part of the rim joist) to the basement wall!
Crawl spaces, especially those in the basement, are notorious areas of neglect that often remain unchecked for years. Wet surfaces or high humidity in the crawl space can support mold and mildew, distort wood flooring and affect indoor air quality. A good alternative to vented crawl spaces is unvented, well insulated spaces. Rigid foam insulation on the interior of crawl space walls is an essential component of unvented crawl space systems which can help keep crawl spaces dry and energy efficient. Just be sure take care of any major water leaks first, by improving the drainage system (fix leaks, add a sump pump, etc.) if there is significant moisture on the crawl space floor.
An important point for consideration
When creating a finished basement and turning the area into a living space, homeowners and contractors must take into account the building codes in their area. The International Codes Council's (ICC) 2012 International Residential Code for One- and Two-Family Dwellings mandates emergency egress and rescue openings must be installed if the basement is being used for various forms of living space. Homeowners and contractors should check if local building codes have adapted this resolution from the ICC or have other basement specific codes before beginning work.
Gary Parsons joined Dow Chemical Company in 1982 and has spent 29 years in various Dow divisions including manufacturing and research and development. He is a Fellow in Dow Building Solutions Research and Development. Since 2006 he has been the technical leader of the development team specializing in building enclosure energy management products and systems. He has a B.S. degree in Chemical Engineering from the University of Cincinnati. He is also a LEED Accredited Professional.