Waterproof Foundation Walls

If you need to waterproof foundation walls, the best available options are:

  • Sheet Membranes
  • Bentonite
  • Liquid Membranes

All three options provide great value. Since fixing water damage to a foundation can be very expensive, taking preventative action against this problem is a very smart decision. Because each option is the most effective choice for certain applications, it's worth learning more about all three so you'll know which one is the right fit for your project.

Sheet Membranes

This option allows you to waterproof foundation walls by applying a barrier to their exterior. Sheet membranes are generally made from very durable rubber material. There's a very strong adhesive on one side of these sheets. That adhesive ensures that when you apply the membranes, the bond they create with the foundation walls is going to last. While you can use this option for DIY foundation waterproofing, you will want to enlist the help of a friend or family member. Since these sheets' adhesive is so strong, you'll want someone to help you position it so you don't accidentally stick it in the wrong place.

One of the most useful features of these sheets is their consistent thickness. With some waterproofing options, a common problem is being able to apply them in a uniform manner. But with sheets, this is not an issue you'll ever face. Another important feature is the quality of protection they provide. Because these sheets will fully cover your foundation walls, they will keep all water from entering. If you're concerned that sheet membranes won't fit your foundation walls, they can be cut to whatever size is necessary.


While bentonite is a naturally occurring material, its popularity as a foundation wall waterproofer is actually fairly recent. The reason many homeowners are now using bentonite to waterproof their foundations is because it's capable of absorbing so much water. Bentonite's way of waterproofing also deals with another common foundation issue. Voids and cracks are often found in many foundations. Because bentonite actually swells as it absorbs water, it will simultaneously fill these weak points.

For waterproofing, bentonite is commonly applied in panel form. This option makes it easy to apply bentonite, as well as ensures it can fit foundation walls of any size. While this option is very effective, it won't create any pollution. And although most waterproofing options can't be applied when it's cold outside, this one can.

Liquid Membranes

This option for waterproofing foundation walls is applied with a trowel, roller or sprayer. You can actually find specific membrane products that are designed for each type of application. Once the liquid cures on the walls, it creates a coating that is rubbery in texture. Prior to using this option, you will need to take care of any existing issues like holes in the walls. Additionally, many liquid membranes require you to create a cove at the wall-footing joint by using cement. What's nice about this waterproofing option is it’s easy to apply and affordable.




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