Leaf guards and gravel excluders are required for circular roof outlets to preventthe hdpe drainpipe becoming blocked over time, leading to flooding. The leaf guard is inserted into the top of the hole. The serrated edges will grip onto the inside of the drain connector or outlet.
All concrete will retain an element of moisture within its mass after the construction process, and it is important that once the roof is waterproofed, there is still a way for water vapour to escape from theconcrete slab. If not, there is a risk that this retained moisture can build up pressure points beneath the waterproofing membrane causing the waterproof seal to bubble, blister or even burst. Therefore, vents are an essential part of a waterproofed concrete deck. Vents should be placed at least every 25m2.