I’ve been impressed at several recent installations of closed cell SPF foam insulation for residential construction.
During one recent installation our client needed to insulate a basement wall. Their objective was to avoid moisture problems and mold, therefore we recommended that they choose their insulation materials carefully. The majority of homeowners in the past have insulated their interior foundation walls utilizing fiberglass bats. Many times it’s because of cost considerations. Fiberglass insulation is relatively inexpensive, however, when fiberglass bats come in contact with concrete it can lead to moisture problems with the air condensing against the colder concrete, which can potentially result in mold growth and potential rotting of the 2×4’s, especially the plates. Many installers try to leave at least a 1 inch air space between the 2×4 and the concrete, which is the preferred method for construction, however, if you’re thinking long-term, I feel that fiberglass bats belong on the second and third floor and not against the basement walls.
A great solution…insulate the concrete basement walls with closed cell spray foam insulation. The first step would be to look for any existing cracks or any moisture or condensation and take care of that problem first with Waterplug, Thoroseal, or other water sealing products, and make sure the integrity of exterior drains, gutters, and drainage away from the house is in place.
Next frame the interior of the walls with 2x4s approximately 1 inch away from the concrete wall.
Next contract with a professional spray foam contractor who has considerable experience in these types of installations. It’s important to pick a well-educated professional who is completely familiar with the new products being offered in today’s market, and understand the correct way to install the product.
Ask the contractor to spray in approximately 3 inches of closed cell foam between the 2×4 studs and feather it into the concrete wall. This will leave a dead air space between the foam insulation and the sheetrock which will be installed over the 2x4s for finish.
The end result…an installation with lots of integrity done the right way.
Closed cell foam is by far the best product to use for these types of installations for the following reasons:
- Closed cell spray foam provides a higher R-value per inch than less expensive insulation.
- Closed cell spray foam is a vapor retarder and helps stop air transfer and moisture from spreading. Moisture management is critical and closed cell spray foam is classified as an acceptable “flood-resistant material” by FEMA.
- Closed cell spray foam adds to the structural integrity of the supporting members. It creates additional racking strength to walls and joists, and has strong adhesion compared to other forms of insulation. The product literally reinforces the strength of the object it’s sprayed onto.
- Closed cell spray foam will eliminate the majority of air leakage. This is an important consideration to help with moisture problems, insect and rodent penetration, and noise from the exterior. Stopping air leakage will reduce a home’s annual heating and cooling costs.
- Closed cell spray foam will reduce noise and sound vibrations. This product definitely helps minimize sound infiltration through walls.
- Closed cell spray foam will help improve indoor air quality by eliminating considerably mold and mildew growth, condensation, and dust.
- Closed cell spray foam is much easier to use when insulating around the joists where they connect with sills. Thermal bridging is a significant cause of energy loss with gaps like you see in conventional insulation. Spray foam creates a tight seal that literally encapsulates the adjoining materials for complete coverage. Gaps and voids are commonly seen when fiberglass insulation is used. Essentially the product results in a much higher R-value than fiberglass insulation, which translates into lower energy bills.
During a recent installation for a property we sold we hired Marksprayfoam LLC out of Meredith, NH. Mark Perrault and his wife Tammy are a husband and wife team that specializes in closed cell spray foam throughout central NH. They reach down into Massachusetts and the Seacoast as well. They have been in business for 5 years, however, Mark has been specializing in insulating properties since 1992—that’s plenty of experience! He initially got started, like all contractors, installing fiberglass bats, and then got intrigued with spray foam insulation in 2003. You could say he and his wife specialize in crawlspaces, older antique homes, basement finishes, and custom jobs as well. All of their materials come from a spray foam distributor out of Woodstock, NH. I found them quick and responsive. They were out the next day installing the product, and got the job done on time and cleaned up the entire site…a very professional installation. I’ve got to say, the consumer was extremely happy with the installation. A nice clean looking job, air tight, and most importantly, provided the consumer with a feeling of security in terms of future moisture penetration. Their foundation walls were constructed completely with concrete cinderblocks in the 1960’s. The addition of the foam added structural integrity to the cinderblock construction from the inside and helped act as a vapor barrier from future condensation problems in order to eliminate any possible mold growth.
Marksprayfoam LLC can be reached at (603) 677-2497, or at email@example.com.
For many older properties out there, antique homes with stone foundations, etc. closed cell spray foam is an ideal application to install under the floor joists and crawlspaces because it completely encapsulates the wood and helps insulate the source of where you want the heat. It’s also a great deterrent for rodents. If preferred, you can insulate the stone walls or makeshift foundation walls with the foam instead of insulating under the floors. Pay special attention to the vapor barriers that you create so that it is not overdone. You still have to allow the crawlspace to breathe. Additionally, if you were to install fiberglass bats in older antique homes with dirt crawlspaces it often leads to considerable mold growth because of the moisture and condensation and differential between a damp dirt floor and the space heated above. It also provides a warm space for mice and rodents to crawl up into during the winter months and create an absolute mess. Close cell spray foam insulation appears to be an excellent alternative compared to previous conventional methods of insulation.
Post written by Frank Roche, President, Roche Realty Group, Inc.