How to install roof flashing

Flashing is used to protect, seal and weatherproof the hips in your roof. The hips are where there is most chance of rain and wear and tear taking its toll and the area of most weakness on a roof so it's worth getting flashing installed. Read this guide on how to install flashing yourself.

Level of difficulty

Level 3: Advanced

What you need

  • Bevel gauge
  • Roof flashings
  • Chisel
  • Hammer
  • Bituminous paint
  • Paint thinner
  • Paint brush
  • Galvanized nails.
  • Steel wire wool
  • Saw
  • Cement
  • Mortar
  • Trowel

The steps to follow

Note:
Roof flashings come in different materials. Most metal roof flashings are made of aluminium, copper, galvanized steel or lead. Galvanized steel roof flashings are most widely used but aluminium and copper flashings are the most durable type of flashing.

  1. Measure the length of the roof you plan to protect with flashing.
  2. If you have existing flashings on the roof, carefully scrape them off with a chisel and hammer.
  3. Cut the flashings to the required measurements and angle. If you need to cut the flashing at a specific angle, use a bevel gauge to measure and transfer the measurement onto the flashings.
  4. Sand the edges of the flashings with steel wire wool to dull the edges.
  5. Brush a coat of flashing primer on the roof's surface and let it dry.
  6. Fold the flashings halfway in the middle, lengthwise.
  7. Tuck the top edge into the roof shingles and brick work.
  8. If your flashing has a self-adhesive backing, simply peel off the backing and stick the flashing to the surface.
  9. Use a wallpaper seam roller to smooth the flashing onto the surface.
  10. If the flashing doesn’t have self-adhesive backing, you’ll need to secure it with nails. Nail the flashings as close to the edge brick work as possible.

Note:

  • When you hit an internal corner while installing the roof flashing, make a small cut at the lower edge and overlap it.
  • For external corners, cut a square patch and place it at the corner. Make a cut at the corner to allow the cut edges to wrap round the corner.

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