Finishing Basement Walls with a Vapor Barrier

To make a basement into a livable space, finishing basement walls is a necessity. Concrete is not insulated, let alone waterproof. Finishing basement walls with a vapor barrier will help make them waterproof. When you put up framing, insulation and drywall, you can be secure in the notion that your basement will remain dry. Finishing basement walls using a vapor barrier is easy, and the article below will show you how.

Step 1 – Remove the Damage

If your basement wall is brand new, then you can skip this step. Over time, your concrete basement walls can become damaged due to many factors. The concrete may not have cured correctly, or the mortar was applied incorrectly in the case of individual blocks of concrete. There may have been excessive dampness or water present in the concrete. The most common reason for damage is the settling of a house. Finishing basement walls with a vapor barrier is not hard, but it can be a tedious job. Inspect every inch of the walls. Look for any holes, cracks or pieces of loose concrete. Use yellow spray paint to mark the areas. Grab a wire brush, and begin scraping at the damaged areas you marked. You want to be gentle and only remove loose bits of concrete. When finished, vacuum up the debris.

Step 2 – Clean the Walls

Finishing basement walls requires that you have a surface free of oils and other naturally occurring substances. Choose a cleanser that is pH-neutral. Use a soft-bristled scrub brush to begin scrubbing the walls with it. Rinse the walls down with clean water, and allow them to dry. If you are in a hurry, you can run a dehumidifier, which will leach water vapor from the air.

Step 3 – Repair

All of those cracks and holes you discovered and cleaned now have to be repaired. Fill the cracks and small holes using joint sealant. Apply the sealant with a putty knife by spreading it evenly over the area. Make sure you feather it so that it is flush with the wall. For large holes, you need to prep them by applying epoxy gel around the edges. You will then fill the area with shrink-resistant mortar. Level the mortar using a trowel. Allow the mortar to dry according to the directions.

Step 4 – The Vapor Barrier

Spread the mastic over the wall using the flat side of a trowel. Spread it out evenly. Go over the mastic using the notched side of the trowel in order to create grooves. The mastic needs to set for 30-minutes. Place the vapor barrier evenly on top of the mastic, and press it into the mastic. Overlap new sheets by 4 inches. Trim the sheets around electrical boxes, pipes, ducts and the like using the utility knife. Trim away excess lengths of plastic. Use spray adhesive to seal the vapor barrier around the edges.