Proper Installation of Basement Window Wells to Cement Blocks

Installation Guidelines

• You will need to excavate the holes for the window wells. It’s important that the holes are properly across the window openings. Make the height of the window wells a maximum of 44-inches from the floor of the well. Read the window well instructions for the proper dimensions for the hole. Typically, the holes must be 48 inches wide and six to seven inches below the window sills. The distance from the foundation wall to the front of the well must be at least 36 inches.

  When cutting the foundation, use a concrete demolition. You can rent the saw from a home improvement rental center. Make sure you wear goggles and the appropriate clothing because the saw creates a lot of dust. Once the opening is finish, use pressure-treated 2-by-8-inch lumber to frame the window opening. Use construction adhesive and masonry fasteners to secure the boards to the concrete blocks.

  Drive the fasteners in the mortar between the blocks. This will ensure that you don’t split the blocks. Use 2-1/2 hardened concrete nails or acrylic adhesive anchoring. The adhesive anchoring is simple to use; it entails drilling a hole, dispensing the adhesive and inserting a threaded rod that is ½-inch in diameter and four inches long into the opening.

  Follow the product instructions for installing your window. Use wooden shims as necessary to make sure that the window is straight and level. It’s important that you properly seal around the perimeter of the window with caulk so that it is watertight. It’s best to use a polyurethane sealant.

  Now you can complete the installation of your drain. The most effective drainage method is to tie six-inch pipe into the foundation drainage system. You want to be assured the drainage is sufficient for heavy rainfall. Keep in mind that the floor or the well fill be finishes with about a foot of rocks when you put in the vertical riser for the drain. Determine the finish height of the window well, which is usually three to four inches above the soil.

  Generally, the well will sit 8 to 10 inches lower than the window sill. Refer to your product directions. Now you can fill the well floor with 12-inches of course rocks (1/2-inch diameter) and set the well in place. Put an addition 2 or 3-inches of stone along the foundation wall and slope the rocks 1-inch per foot away from the foundation wall. The well should be a minimum of 2-inches above the well floor. Attach the well to the concrete blocks with the acrylic adhesive anchoring system outlined above.