Any building materials in contact with the ground must be properly rated and designed for ground contact. Termites, water damage, and other factors can cause deterioration over time and lead to serious damage. Choosing effective systems for protecting your foundation walls saves you money and headaches while making your walls stronger and longer lasting.
Why is Protection Necessary?
Critters and nature can wreak havoc on materials in contact with the ground. Carpenter ants, termites, and other insects will nest in anything they can find, including many types of building materials. Pests and rodents will take advantage of routes into the wall if they can find or make them. Water is also a concern any time building materials have ground contact. Water can cause deterioration and rot over time and can be sucked into the wall due to capillary forces.
The Most Effective Protection for Foundation Walls
Many systems and methods exist for protecting foundation walls. Choosing the best for your home depends on your specific situation. Some of the most effective methods are listed below:
Clearance to Grade
The International Residential Code (IRC) recommends a 6-inch distance between grade and any untreated wood. Some states go further and require 8 inches, so it’s important to check your local building codes. Prevent mulch, pavers, plants, or other features that raise the grade from getting too close to your home’s foundation walls. Keeping water away from your home’s foundation walls is critical to keeping your walls healthy. When relying on clearance to grade as your main form of protection, maintenance is key.
External Protection
Adding an external coating can help give your home’s foundation walls an extra layer of protection. Most approaches involve applying a stucco-like finish with a surface-bonding cement. Some of these finishes are thin enough to be painted on while others are similar to a thick acrylic-modified mortar. Hardware cloth or fiberglass lath is sometimes used as a back layer to give the protective surface more strength. These surfaces work as long as the surface stays in good condition, but unfortunately these types of protective surfaces can be prone to chipping and must be repaired regularly.
Water Routing
Keeping water away from the foundation is critical for the health of the foundation’s walls. Make sure that water will properly shed away from the home and can drain easily. Gutters are a great way to control and route the flow of water away from the home. Gutters should flow into downspouts which direct water at least ten feet away from the home’s foundation.
Waterproofing Membranes
Waterproofing membranes work by giving waterproof characteristics to materials that typically cannot stand up to much water exposure. Available as spray-on, brush-on, or roll-on types of membranes, they are typically applied during construction. Once buried, the membrane protects the wall from moisture. These systems can work well when properly applied, but leave a great deal of room for human error.
Dimple Mats and Drain Boards
Part of the issue with waterproofing below grade walls can be moving the water that does get in, away from the walls. Typically made from high-density polyethylene sheets with dimples along the surface, the dimple sheet is installed so the dimples face the foundation wall. The dimples create an air gap between the sheet and the foundation wall. Any water that gets through the membrane is then able to drain away from the wall.
Below Grade Safe Materials
While most organic materials will not do well below grade for the long-term, some products work just fine. Closed cell foams like those used in Rmax polyiso foam boards resist water absorption and are of no interest to insects and other pests. Additionally, polyiso boards resist compression from soil loads while retaining exceptional thermal performances. The other benefit of using polyiso on a below grade wall is the added insulation benefits that keep the walls warm and reduce the potential for condensation on the inside surface of the wall.
Rmax Polyiso: The Superior Solution
Rmax polyiso insulation boards are built to withstand the challenges faced by below grade foundation walls. Backed with a water shedding facer, Rmax polyiso properly sheds water keeping the foundation walls safe and in good condition. Combined with the other mentioned best practices, Rmax polyiso is hard to beat!
To learn more about Rmax polyiso’s exceptional below grade performance, reach out to our insulation experts today.