External Wall Waterproofing
We do waterproofing for external walls on both new builds and we do rectification works.
Waterproofing an external wall prevents the ingress of water over time which can weaken mortar and bricks causing structural damage. Water ingress is most noticeable when it begins to cause paint and plaster to peel from the inside wall of the building.
This page is about walls which have lateral water seepage which occurs from failing mortar or very old bricks/blocks which soak up water quickly. The image to the left is a house that has a double brick wall with no cavity and water was passing through 80M² of the wall. The house’s dampcourse was in tact and the house had no rising damp. The internal wall of the house had blistering plaster on the entire interior wall of the house. This job took around 8 days in total including repainting the wall with a standard weathershield paint.
If you only have damage occurring at the bottom of your walls or specific salt lines in your walls then please see these pages: 1. Rising Damp & 2. Efflorescence.
Often inner city houses have Sandstock bricks which are very soft and have become chalky over the years creating the perfect situation for the seepage of water to the internal wall of the building.
There are 2 main ways to waterproof an ABOVE GROUND wall like this.
- Waterproof directly over the existing paint.
This is a cheaper option but can fail. The reason it can fail is that the waterproofing is relying on the adhesion of the old paint to the wall. If the paint peels or deteriorates then it will cause the waterproofing to be “drummy” and could cause a penetration for leaking. We will happily use this method if you so choose although we will not give a warranty. This system uses 1x coat of epoxy primer and 2 (or 3) coats of UV stable waterproofing membrane.
- Remove existing paint and apply an epoxy primer then waterproofing membrane.
This option is more expensive although we will give you a 10 year warranty for this system. Removing the existing paint gives the waterproofing primer a porous substrate to adhere properly similar to the way a key fits into a lock. The primer acts like a solid bridge between the substrate and the waterproofing membrane.
After the primer is applied we apply 2 (or 3) coats of UV stable waterproofing membrane which is paintable and will protect your property for a minimum of 10 years.
If you have bubbling plaster or wet walls inside your house we have extensive experience in solving these kinds of problems.