This has largely been superseded by electronic testing as a means of establishing the waterproofing integrity of a roof or other installation.
Flood test roof.
In many parts of the country roof design live loads are 20 psf which for large tributary areas can be reduced to 12 psf.
However most roofs when properly constructed are positively sloped to drains.
It can still be useful however where finishes are in place and electronic testing is impractical.
If you contemplate flooding your roof please check with your structural engineer.
Water height is maintained so as not to exceed a minimum level of 2 inches below the edge of flashings.
Manufacturers should specify a minimum time period for materials to cure prior to performing flood test however no testing should be performed during the first 24 h following installation of system materials 48 h min if materials are installed at a time when ambient temperatures are below 10 c 50 f.
A membrane integrity test conducted by temporarily plugging or otherwise closing any drains and erecting temporary dams where required to retain water on the surface of a waterproofing membrane and then flooding the surface to a maximum depth of 2 inches at the high point.
The drainage path of test water on lower areas of roof or walls must be tested to be certain they do not contain the leak location.
Leak detection using flood testing.
Flood testing to detect leaks and verify the quality of newly installed assemblies has a long history in the roofing industry.
Testing is performed for a minimum of 24 hours and maximum of 72 hours when rainfall is not forecasted to occur.
It is commonly referenced as the standard for flood testing roof systems.
It is possible you will have to pick him up off of the floor.
Plug and drain to check for leaks around the plug and drain installation before proceeding with the full test.
Water weighs 1000 kg m3 62 4 lb ft.
20psf corresponds to just under 4 inches of water.
Test area is flooded with water to achieve a minimum cover of 1 inch but not exceed a maximum depth of 4 inches at the lowest point.
Flood testing is the oldest simplest and basic method of testing a roofs integrity.
Flood the area being tested with potable water to a minimum depth of 1 25mm to a maximum depth of 4 100mm at the low point of the test area.
Astm d5957 standard guide for flood testing horizontal waterproofing installations is a guide for conducting flood testing of horizontal surfaces with slopes no greater than 1 4 in.
If a flood test calls for a depth of 50 mm 2 in it would add 50 kg m 10 lb ft to the dead load.
Typically a roofing contractor will have a technician on the roof performing the water test itself and also a technician on the inside of the building to radio in when the water starts showing up as a leak.
Flood testing can cause irreparable damage to the roofing system or even the supporting structure.