Flat roofs have inherent problems, but if you keep up with their maintenance they can withstand the onslaught of the British weather for a good number of years.
One of the biggest problems with a flat roof is a crack in the roofing felt. It is however easy to do a simple patch repair, you can even do the job yourself.
The first thing to do is check that the damage doesn't extend to the roof deck; you should be able to check this by simply pushing on the deck to feel for any sponginess. Using a sharp knife cut the damaged section away in a uniform shape. A square or rectangular shape is best so making a new patch will be easier. If you have removed more then one layer of felt you will have to make this up with the same number of replacement patches. Use roofing cement to seal the areas around the cut-out felt and then apply this to the deck boards. Using a new roofing felt patch, stick it to the cement and nail this into place with clout nails. When the area has been built up appropriately by adding layers of felt, fit the last patch (which should be 5cm bigger than the repair at each side) over the damaged section. Make sure you apply roofing cement around the edges to form a watertight seal.
