A Flat Roof is seemingly self explanatory insofar as it is a roof that is not pitched or sloping. In fact a Flat Roof is not completely flat as a slight incline is required for rainwater to run off into the guttering.
For many years flat roofs have been covered with rolls of asphalt covered with waterproofing made of tar and gravel.
Sometimes water can end up accumulating on flat roofs with an insufficient incline and the roof can be compromised.
Felt coverings to flat roofs have limited durability and can require patch repairs at any time. Full stripping and refelting is normally needed at 10-15 year intervals. Modern elastomeric felts or fibreglass roofing are available which have better durability and resistance to splitting than traditional felt and although more expensive, should be specified when seeking estimates for refelting.