How to Repair a Flat Roof

By eHow Home & Garden Editor

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Water runs right off of sloped roofs, but flat ones must maintain a watertight seal to prevent leaking. When you have a crack or blister in the shingles, water can get underneath and wreak all sorts of havoc.

Instructions

Difficulty: Moderately challenging

Things You’ll Need:

Treating a Cracked or Peeled Area

Step1
Sweep the roof to get any dust or dirt away from your work area. The roofing cement you'll be using won't stick if the surface is dirty.
Step2
Cut out around any cracked or peeling areas with a razor knife and remove each bad section. Make it a uniform shape such as a square or rectangle.
Step3
Use the cutout piece as a pattern and cut a replacement piece of shingle in the same size and shape. If you cut out more than one bad layer, you'll need to cut enough pieces to bring the new section up to the same level as the area around it.
Step4
Cut another patch of shingle about 2 inches larger all the way around.
Step5
Slip a putty knife under the edges around the cutout area. Apply roofing cement under the edges.
Step6
Put a layer of roofing cement down in the entire cutout area with the putty knife.
Step7
Press the new shingle into the hole.
Step8
Tack down the shingle(s) with roofing nails. You should cement only the bottom one; the other layers can just be nailed down.
Step9
Lay the larger patch over the one you just applied and nail it down.
Step10
Go around the edges of this top patch with cement to form a seal.

Treating a Bubble or a Split Shingle

Step1
Treat a bubble by cutting a line in just that layer with a razor knife.
Step2
Pry the cut open and force roofing cement in both sides of the cut. This is also what to do with a split in the shingle.
Step3
Tack down both sides of the cut or split with roofing nails, and cover it with a patch as described in "Treating a Cracked or Peeled Area."

Tips & Warnings

  • Use a straightedge when cutting the shingles. This will make it easier to match the size and shape.
  • Be careful when walking on the roof.
  • Step lightly. You can do a lot of damage stomping around in work boots.

Comments

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Anonymous

Anonymous said

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on 1/12/2007 Flat roofs are far less likely to leak if ponding areas (where water sits for more than 24 hours) are filled. There are several asphalt, lightweight cement and acrylic-based products available to fill ponding areas.

Fiberglass seam tape, which is available in rolls usually about 4 inches wide, should be used to reinforce the edges of areas where patches have been applied. This keeps the asphalt cement from cracking as it dries and shrinks.

Rudd said

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on 4/16/2008 First of all, shingles dont belong on a flat roof. Secondly, the article forgets to mention rubber or single-ply roofing which compromises about 80% of flat roofs.

In that case i would consider using a peal&seal type product such as these: http://www.bendtek.com/Roof_Repair_Products.htm

This also applies for metal roofs as well.

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eHow Article:  How to Repair a Flat Roof

eHow Home & Garden Editor

eHow Home & Garden Editor

Category: Home & Garden

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