How To Use Expanding Foam To Stop Leaks And Seepage

Water leaks and infiltrations which can be worked by flood damage restoration company for example are common in places that have not been properly waterproofed or have begun to age. Expandable polyurethane foam is one of the best ways to stop water leaks because the foam will expand into the cracks and help prevent future leaks.

You don’t have to break the wall, change the roof tiles, or remove all the waterproofing products, as the polyurethane gets into the existing cracks and closes them. The product manages to expand the waterproof foam to any surface and will quickly and definitively solve most water leakage problems.

Expanding Foam To Stop Leaks And Seepage

When we talk about infiltrations with the entrance of water, we can talk about three types of situations: infiltrations in the vertical walls or the ground and infiltrations in the ceiling. Water ingress is the first thing you want to avoid urgently, as it causes considerable damage to your property.

Step 1

Before starting, put on your safety glasses and start cleaning the affected area. Scrub the surface of the cracked area with sandpaper or a wire brush. Removing any loose debris and thoroughly cleaning the area to prepare it for the expanding foam is important. If wet, dry the area with a towel and let the wet surfaces be waterproofed for at least a day before spreading foam into the cracks.

Step 2

Before spraying the expanding foam, put on a mask and goggles. As per the manufacturer’s instructions (they vary by brand), attach the applicator, insert the tube’s other end into the slot, and disperse the foam. Spray until the foam fills the entire hole.

Step 3

Don’t forget to spray a small foam layer on all areas where cracks and cracks appear. Spread the foam evenly and quickly over the surface with the help of a spatula; also, apply where cracks are starting to form. Let the lathered areas dry for at least 24 hours.

Step 4

Remove any excess foam from the waterproofed spot and smooth the edges with sandpaper until the foam is flush with the wall face or any other area where you filled the crack with expandable polyurethane. Finish the surface as needed, such as painting, varnishing, wallpapering, or tiling.

Final Considerations

On some structures, it’s normal to see cracks where water can get in, which could cause damage. The best way to solve this situation is to use polyurethane injections in cracks and crevices.


Whether due to deficiencies in coatings, stress, poor practices in the placement of pipes, water leakage in the wall, or soil movement, these cracks are common in concrete walls, foundation slabs, and reinforced slabs, among other constructions. Now that you’re done, you might also be interested in reading the article on exterior wall waterproofing methods.