If the sheet has condensation on the inner surface (next to the wall), the soil around the house may be naturally damp from a high water table or from poor soil drainage. In that case, waterproofing the walls of the basement may be useful. You can waterproof only the interior walls, which can solve the problem. The exterior waterproofing of the basement can solve all these problems.
The basic method is to excavate the soil away from the outer wall of the basement, install the appropriate moisture barrier, fill the surrounding area with gravel, and establish a footer drainage system. A sump pump may or may not be necessary. The basement wall may need some prep work and the moisture barrier may differ; Accurate Basement certified experts will be able to tell you precisely which moisture barrier will work best for your basement. Gravel filling is especially important given the type of soil in our area.
Ground leveling is important when there is water inside basements. If the ground slope runs towards the foundation, runoff can seep into rooms below ground level at times of heavy rain or accidental water problems. A superficial DIY interior repair and an expensive and short-lived exterior waterproofing are not comparable to an interior basement waterproofing system. The best way to waterproof basement walls by hand is to fill the cracks with hydraulic cement (opens in a new tab) and apply a sealant designed to waterproof basement walls, in addition to using silicone masonry putty around the window jambs.
If the foil test showed that water soaks into the basement walls and leaves them damp, seal the inside of the walls with a high-quality waterproof paint, such as DRYLOK White Extreme Waterproof (available from Home Depot). Waterproofing is a factor that should not be neglected even when finishing a basement with a limited budget, but if you suspect that you need to waterproof basement walls in an existing space, take urgent action. Exterior waterproofing requires expensive and complicated procedures compared to internal basement waterproofing.