What are waterproofing membranes? A waterproofing membrane is a thin layer of water-tight material generally used in construction that prevents water from passing through it.
They are often laid on surfaces such as flat terraces, foundations, basements, roofs, and walls protecting your structure. For the best results, the membranes can be laid above the structural slab as well as below the finish tiles.
A waterproofing membrane should be flexible and elastic. In this manner, workers can easily stretch it to properly cover the whole surface. At the same time, the membrane can adapt to the building’s configuration and take any shape required.
It is worth mentioning that waterproofing membranes that will be exposed to direct sun light need to be UV-resistant. Otherwise, the sun light will damage the material quickly reducing its waterproofing capabilities.
Why do waterproofing membranes fail? The most common cause of waterproofing membrane failure is poor work, namely the membranes were not laid properly and the joints were not done perfectly.
Other factors include:
- The surface the membranes were applied on was not completely dry
- Moisture prevented the membranes from properly adhering to the surface
- The surface was not primed beforehand.
Can you patch waterproofing membranes? If your waterproofing membranes got damaged, you can patch the affected area by applying an additional layer of waterproofing membrane or by spraying a new layer of liquid applied membrane.
However, this is only a temporary solution. The best approach is to replace the damaged membrane and apply a completely new layer.
Types of waterproofing membranes
There are two main types of waterproofing membranes: sheet based membranes (pre-formed sheets) and liquid applied membranes.
Sheet based membranes usually come in the form of bituminous, PVC or composite rolls. Workers then unfurl and lay them on the surface they need to waterproof.
The membrane is stuck to the surface with the help of a hot tar adhesive and blowtorches that heat the bottom of the membrane. The same adhesive is then used for the joints.
Obviously, the joints must be done perfectly otherwise water can seep through.
Liquid applied membranes are simply sprayed on the surface or applied with the help of a brush.
One major advantage is that workers can control the thickness of the membrane by simply applying more liquid on a specific area.
Workers need to make sure they apply the right thickness. If the membrane is too thin, it will break or will adhere poorly to the surface.
When applying liquid applied membranes, try to avoid cold joints. Finish waterproofing the area in a single day.
If that’s not possible, you can overlap the new membrane over the old one — just make sure to spray more liquid over cold joints.
As you can see, liquid applied membranes tend to be better than sheet based membranes because they are joint-free.
Choosing the Right Waterproofing Membranes For Your Needs
There are two main questions you should ask yourself when deciding what type of waterproofing membranes to buy:
- What surface you’re going to apply the membranes on
- What chemicals they need to withstand.
Here’s what properties waterproofing membranes should have:
- UV stability — purchase a UV stable waterproofing membrane if it’s going to be exposed to direct sun light to slow down degradation.
- Flexibility and tear resistance — make sure the membrane is flexible and you can easily stretch it, especially if you’re going to apply it on surfaces that move such as steel (which expands under high temperatures).
- Breathability — choose membranes that allow water vapor to pass through.
- Abrasion resistance — your membranes need to be strong enough to withstand wear and tear. Low abrasion resistance membranes get damaged easily.
- Chemical stability — the membranes should not cause any chemical reactions with its environment (they should be chemically inert).
Work With Specialists Only
The best approach is to work with specialists only. Applying waterproofing membranes costs quite a lot of money. If the workers can’t get the job done properly the first time, repair works can be even more expensive.