ᐅ Is drainage necessary under the entrance platform?

Created on: 13 Apr 2016 07:42
H
hg6806
Hello everyone,

We want to install a natural stone-covered entrance platform for our single-family house. It is basically just one step, approximately 2.40 x 1.20 m (7 ft 10 in x 3 ft 11 in) in size. For the material, I chose 60 x 60 cm (24 x 24 inches) flamed basalt slabs.

The platform was poured from screed several months ago. It slopes downward away from the house, so rainwater can drain off.

The question now is, do I still need a drainage system for this? The tiler says no, but a civil engineer friend says yes. If the slabs are properly glued, how could they freeze and be damaged? What benefit would a drainage system actually provide? Water would never penetrate that deep anyway.

Best regards
P
Payday
19 Apr 2016 18:27
I also recommended to the original poster to make the platform from a single piece. It is not really more expensive than using pieces sized 50cm x 50cm (20 inches x 20 inches).

Attached is a picture taken during our winter snowstorm.

Black front door in brick facade, vertical wooden strip, stairs, snow; mailbox on the right
S
Sebastian79
19 Apr 2016 18:34
Well, and yet you still have the connection joint – which in your case isn’t covered either.
P
Payday
19 Apr 2016 18:35
This joint is sealed with silicone. It just needs to be redone every few years.

It’s completely different whether you seal this one joint with silicone (which you have to do anyway for elasticity) or if you need to properly waterproof multiple panels (or get rid of the water). The entire job was done by a professional company that apparently knew what they were doing.
S
Sebastian79
19 Apr 2016 18:37
Exactly, you have to do that too – once there is plaster, it gets more complicated...

You can do a lot, as long as you are aware of the potential risks.