Because it has no slope and water therefore has more of a tendency to pool, the flat shed roof is more vulnerable to leaking than a pitched roof. To keep this type of roof from leaking into your shed, you will need to perform periodic maintenance. This is particularly true where you find shingles with cracks, bubbles, or blisters that are more likely to allow water to find its way beneath these shingles. Here are a few tips to prevent these leaks.
Tip 1 – Clean Your Roof before Applying Roofing Cement
Because most shed roof repairs will involve applying roofing cement, you must always remove dust or dirt from the roof's upper surface that is to be repaired. Use an efficient broom and sweep any dirt, dust, or debris away from the area you'll be repairing. Otherwise, your roofing cement will fail to stick to the roof surface.
Tip 2 – Remove Roofing that is Damaged
Don't try to seal shed roofing that is cracked or peeling. You're far better off removing this damaged roofing and replacing it with new material. To efficiently remove these damaged areas, use a utility knife or razor knife and a straightedge to cut around the damaged area. You'll find that cutting a uniform shape such as a square or rectangle, one with straight, clean edges, will give you a better seal. If you have multiple damaged areas of approximately the same size, use your first replacement piece as a pattern to cut and remove other damaged areas.
Tip 3 – Removing More than One Roofing Layer
Where it is necessary to remove more than a single layer of roofing, you'll need to cut enough material to bring your roof surface up to the same level at the roofing surface adjacent to it. Failure to do this will most likely result in pooled water on the replaced roofing.
Tip 4 – Applying Roofing Cement to New Replacement Pieces
In gluing down your replacement pieces, be sure to adhere the edges of roofing surrounding the replacement piece. You can do this by using a putty knife to lift the edges of the older roofing around the new piece. When you have the edges raised, apply and spread the cement evenly on all surfaces to be sure it is properly sealed. Apply the cement to the entire surface, spreading it evenly with the putty knife.
Tip 5 – Attaching the New Shingle (Replacement Piece)
Press the replacement piece firmly down into the space left by the removal of the damaged piece. Lay other layers of shingles where necessary to create an even surface. The top piece should be about 2 inches larger in area than those tile pieces beneath it. Then, tack down all these shingle pieces with roofing nails, and seal all holes and edges.
Tip 6 – Repairing Roofing Bubbles or Splits
To repair roofing bubbles, use your knife to cut a slit in the roofing bubble to allow any air in the bubble to escape. Lift the edges of the split or bubble, and apply roofing cement under all surfaces of the shingle around the bubble or split. Then cover the area with a patch as in Tip 5.