“What’s Your BuildIQ?” Column : Water Management for Foundations

An elastomeric asphalt coating or a sheet of polyethylene between the footing and the wall, as well as under the slab, creates a capillary break that keeps water from traveling through the footings to the slab or wall.

In the past, homeowners assumed that their home’s foundation would get wet. A little moisture in the basement was to be expected, so homeowners devised strategies for keeping valuables off the floor. But as homeowners demand better performing homes, good water management for foundations is critical to ensuring a dry, durable foundation. Water management strategies should promote water drainage to prevent mold growth and other water damage to the home.

Do you and your team know the best practices for managing water for foundations? The following questions will test your BuildIQ. Stumped, or want to learn more? Visit http://hz.buildiquniversity.com.

1. Which of the following is true?
A. Dampproofing is very similar to waterproofing.

A is incorrect. Dampproofing consists of a thin asphalt coating. A waterproofing system must have two components: an elastomeric asphalt coating to protect the wall surface, and a drainage component to relieve hydrostatic pressure.

B. When the foundation wall cracks, a dampproofing skin can crack with it.

B is correct. Dampproofing provides only a thin coating, so if a crack opens up in the concrete, the dampproofing skin can crack with it, creating a possible leak.

C. Typically, the elastomeric asphalt coating should extend only to grade.

C is incorrect. Typically, the elastomeric asphalt coating should extend 4 inches above grade.

2. Which of the following defines a capillary break?
A. The force by which a liquid, when it's in contact with a solid, is raised or lowered by the attraction of the liquid's molecules to each other and to the molecules of the solid

A is incorrect. That's the definition of capillary action. A capillary break is a material or space that's inserted between two solids to keep liquid from moving from one solid to the other. You can create a capillary break between the footings and the foundation wall by spraying an elastomeric asphalt coating on the footings.

B. A material that's used to minimize water vapor movement from an area of high concentration to an area of low concentration

B is incorrect. That's the definition of a vapor retarder. A capillary break is a material or space that's inserted between two solids to keep liquid from moving from one solid to the other. You can create a capillary break between the footings and the foundation wall by spraying an elastomeric asphalt coating on the footings.

C. A material or space that's inserted between two solids to keep liquid from moving from one solid to the other

C is correct. You can create a capillary break between the footings and the foundation wall by spraying an elastomeric asphalt coating on the footings.

3. You're checking the elastomeric asphalt coating on the foundation walls. Which of the following is true?
A. The coating should extend from the footings to 4 inches above grade.

A is correct. Make sure that the application extends to all foundation walls, the footings, the joint between the walls and footings.

B. The footings shouldn't be coated.

B is incorrect. The elastomeric asphalt coating should extend to 4 inches above grade. Make sure that the application extends to all foundation walls, the footings, the joint between the walls and footings.

C. The joint between the wall and the footing shouldn't be coated.

C is incorrect. The elastomeric asphalt coating should extend to 4 inches above grade. Make sure that the application extends to all foundation walls, the footings, the joint between the walls and footings.