Reversing the direction of fall Post your questions and get answers regarding all areas of drives, pathways and patios

[Tommy]

I have a concrete shed approx.10 ft. by 10 ft.,with a reinforced concrete roof approx.6 inches thick one end and 5 inches the other end to let the water run off.
I want to reverse the slope so that the water will run off the opposite end to what it is now.
Also I want to know what preperation I need to make it waterproof and also the mix.

[bg]

To reverse the fall in concrete you would need to add a minimum of 75mm at the high end going up to 125mm at the other. This would be a huge weight but 75mm of concrete is the minimum suggested for construction water tightness. It would be better to fix timber firring pieces (Timbers cut to a lope) to the concrete and put ply decking on. The ply could then be covered in felt, fibreglass or rubber. See the flat roofingf project on the website via www.diydoctor.org.uk/projects.htm