ᐅ Manufacturer KMB, Wet Layer Thickness, Floor Moisture

Created on: 8 Jul 2012 15:48
W
wadi1982
W
wadi1982
8 Jul 2012 15:48
Hello.

We want to waterproof the precast concrete basement of our new build.

According to the soil survey, in case a drainage system is installed, waterproofing against ground moisture / non-pressing drainage water is sufficient.

Our plan is as follows:

- Roughen the basement surface, break the edge of the floor slab and sweep clean
- Brush on a slurry seal at the joint between the floor slab and walls, then immediately create a fillet with cement mortar while still wet (fresh-in-fresh)
- Once the fillet has dried, prime with a bituminous primer and let it dry

For the actual waterproofing, we plan to apply two layers of single-component liquid waterproofing membrane (KMB) with reinforcing fleece in between.

Until yesterday, I thought I understood everything clearly.

The manufacturer of the liquid waterproofing recommends a wet coat thickness of 3.7 mm (about 1/6 inch). So, we simply rounded up to 4 mm (around 5/32 inch).

The plan is to apply 2 mm (about 1/12 inch), press the fleece into the still wet layer, let it tack off, then apply another 2 mm on top—making a total wet thickness of 4 mm.

Yesterday, however, I came across an article about liquid waterproofing which stated that for our exposure condition, a wet coat thickness of 4 mm per layer is required.

How should this be interpreted? Do we really need to apply 2 x 4 mm (a total of 8 mm, or about 5/16 inch) if we use two layers with fleece in between? Intuitively, that seems quite thick.

What should the total thickness of the liquid waterproofing be?

For completeness: After the liquid waterproofing has fully dried, 100 mm (about 4 inches) polystyrene insulation boards will be adhered with two-component liquid waterproofing. Then the four window wells will be installed, followed by a dimpled waterproofing membrane as backfill protection.

Thanks in advance.