10 Common Questions about Waterproofing concrete foundations

waterproofing concrete foundations

10 Common Questions about Waterproofing concrete foundations

waterproofing concrete foundations

We have been in this concrete game for a while now and believe us, there’s always a new question. -but what about the old questions? What about the ones we are always asked? And what about waterproofing concrete foundations? Well, we’ve researched the most searched and asked questions on Google and attempted to answer them here. Because in 2022 everyone want’s their space to start and STAY waterproof.

1. Waterproof and Damp proofing

If you’ve recently embarked on a concrete and construction related build or project, you would have come across a few confusing terms when waterproofing concrete foundations. Not only are there several ways to waterproof there are other terms for similar processes. So, what is damp proofing? -And is it a swap for waterproofing? See the table of definitions below.


  • The intention with waterproofing concrete foundations is to keep out both moisture and liquid water.
  • Can be applied pre or post pour.
  • May require 1 product or a waterproofing system.
  • Usually an engineering requirement.
  • More popular than damp proofing.

Damp proofing

  • The intention with damp proofing is to keep out soil moisture. AKA ‘dampness’.
  • For areas that are not required to be waterproof but are below grade foundation walls.
  • Typically done during original construction process, for areas without high soil hydrostatic pressure.
  • Used in conjunction with appropriate lawn drainage and other efforts to keep dampness out of the structure long-term.

2. What is a ‘Waterproof Membrane’?

A waterproofing membrane is a collective term for a layer of water-tight material that is applied to a surface to prevent water leaks or damage. The ‘Waterproofing membrane’ generally consists of a liquid applied waterproofing agent or pre-formed sheet membranes.

At Danterr we supply many different components that fall into the waterproofing membrane category, including liquid, tape or sheets and other products. We can also work with you to create a waterproofing system that will work for your build.

waterproofing concrete foundations

3. Bituminous Vs Cementitious Vs Water based waterproofing membranes

There are three basic types of liquid membranes used when waterproofing concrete foundations. We have listed the differences in the below table. For your convenience we have also listed the product that we sell that is akin to the type of liquid membrane. So, if you see something you need, don’t hesitate to get a free quote by clicking on this link.

Rubberised Asphalt

  • Used underground for foundation protection.
  • Usually feature a non-woven reinforcing fabric layer as well as the liquid.
  • Very tough, durable and flexible.

Water Based

  • Highly flexible.
  • Usually a liquid membrane.
  • Good for under tile, underground and immersed waterproofing.
  • Useful for retaining walls, ponds, slabs and other everyday structures.


  • Usually, a powder that consists of sand, organic and inorganic chemicals, and silica-based substances.
  • Mix to combine.Can incorporate an acrylic additive.
  • Easy to apply but lacks flexibility.

4. Torch-applied Bituminous Membranes – What are they?

Torch-on membranes are used for both commercial and residential construction sites in areas prone to water POOLING. This type of membrane is made from bitumen and varied polymers. There are two types of torch-on membrane APP and SBS.

APP – Atactic Polypropylene Plastic, is a plastic modified asphalt that melts quickly and flows like liquid wax.

SBS – Styrene Butadiene Styrene is a rubber modified asphalt. SBS takes longer to install than APP because it does not torch as easily however it is more pliable and therefore can be used for areas that need flexibility. SBS does tend to last longer than APP.

Typically, a torch-on membrane is used for flat concrete roofs, foundation and retaining walls, flashings, expansion joints or any specified area where a stronger membrane is required as it has high resistance to mechanical damage, extreme weather, and puncturing.

5. Does waterproofing membrane stick to silicone?

We noticed this question gets searched a lot and although it pertains more to the residential sector, we reached out to some experts anyway.
Silicone sealants will NOT stick to a polyurethane waterproofing membrane. They do NOT cure correctly, and you are best to use a water-based waterproofing membrane in your bathrooms, kitchens and wet areas when building, constructing and renovating. For a deeper look at silicone vs polyurethane see this blog.

So, what about in commercial use?

Polyurethane sealants WILL stick to polyurethane membranes, be it in a liquid or tape form. A polyurethane sealant is most used in a total waterproofing system (See Q7), when completing joins that require comprehensive waterproofing. Example: culverts

6. Is waterproofing membrane necessary?

A ‘waterproofing membrane’ is simply the name for any layer of watertight material that is placed on a join where waterproofing is necessary. These materials may differ in application style and usually feature either a liquid or tape like medium that adheres to surface after priming or cleaning.

7. What is a waterproofing system?

A ‘waterproofing system’ is the language used for a series of waterproofing products used in conjunction to seal joins and surfaces. For example, SILCOR® LM PU Sealant, Bituthene® primer and Bituthene® 5000 or 3000 membrane tapes.

8. Why do waterproofing membranes fail?

Waterproofing membranes fail due to poor application, expired materials like sealants and primers, poor surface preparation and incorrect selection of materials. In other cases, a lack of coverage or adhesion is often the cause. Combat this by working with engineers and product specialists like us.

9. What is the difference between a waterstop and a waterproofing membrane?

A waterstop is an in-situ product that is used to stop leakage and moisture damaging a joint by being incorporated in to the joint before the slab is poured.

A waterproofing membrane is applied to the concrete join after the concrete has been poured. It can be placed not only to the join but all over the surface to protect from moisture on all sides of the slab.

10. What waterproofing products can Danterr supply?

From waterproofing membranes to waterstops, we can service your civil or residential project with quality, excellence, and great product knowledge.
Below we have compiled a slideshow of some of our most popular waterproofing accessories.

waterproofing concrete foundations

We will always do our best to provide you with the correct and highest quality product when quoting your enquiries.

Contact sales@danterr.com or call 1800 262 383 with your enquiries.