This story shows you how to install a flat roof with modified-bitumen roofing.
Flat roofs were once exclusively the province of professionals, but new materials enable do-it-yourselfers to install flat roofs. If your flat roof is covered with gravel, you will likely need to hire a professional to reroof it. If the surface is smooth you may be able to reroof using sheets of modified bitumen or EPDM (rubber) roofing.
Consult with your inspector to see whether you need to tear off the old roofing or if you can reroof over the existing roofing. Use flashings approved by your building department. Modified-bitumen roofing may have a granular surface as shown here or it may be smooth. If you install the smooth product, cover it with aluminum coating.
These steps show a "torch-down" method, which looks a bit scary but actually is not difficult. Renting a large propane torch is inexpensive. You can also set the sheets in adhesive; this sounds easier but is actually messier and more time-consuming.
One or two days, working with a helper, to lay insulation and modified-bitumen roofing for a 500-square-foot roof
Tape measure, hammer, chalkline, large propane torch, utility knife with hook blade, spark igniter
Measuring, cutting, using a torch
Measure and make a drawing of the roof and consult with a dealer.
Roof insulation, heavy roofing felt, modified-bitumen roofing, drip-edge and other flashings, spray primer, cap nails, roofing nails, roofing cement
Remove all obstructions and sweep the roof clean of debris. You may need to remove old flashings.
If your roof is not already insulated, it is usually worth the time and expense to lay sheets of rigid insulation made for a flat roof. Cut them to fit fairly tightly and make sure that you will support the flashing pieces at the ends. Attach the insulation with fasteners as recommended by the manufacturer -- in this case hold-down plates and specially-coated screws long enough to penetrate the decking.