If you find that weather or accidents have damaged your fiber cement roofing, then you will need to perform some quick repairs before the next bout of rain. Fiber cement roofing is a complex material made up from a mixture of cement and fibrous material such as cardboard, cloth, or fiberglass. If you need to repair a wide area, then you might be better off calling in professional help, but if it is only a little bit of damage, then you will be able to manage this yourself. Fixing fiber cement roofing is not a difficult job, but it can be time consuming, so allow a full day to complete this task.
Step 1 - Clean the Roofing
The first step in any type of repair on your fiber cement roofing is to clean it thoroughly. This will ensure that you don't get any dirt or debris wrapped up with the paint and tar that you will be applying later. It is a good idea to scrub down the roof using a hand brush and some liquid soap, but you can use a pressure washer if your roof is still water-tight.
Step 2 - Inspect the Damage
Now all of the debris has been removed, inspect the roof for damage. Look at the broken tiles, and decide whether they need to be discarded or patched over. Small holes can easily be patched without the need to replace, but cracks and breaks will have to be replaced.
Step 3 - Add Patches
Cut out some fiberglass cement shingles to the right size, plus about an inch extra. Using some roofing tar, spread this over the surface of the tile to be mended, and then place the patch onto the hole. Press down around the edge to fix the patch into place, and then add more roofing tar over the top, plus a little caulk around the sides to ensure that there are no leaks.
Step 4 - Replace a Shingle
Take off the broken shingle by removing the nails, or lifting up the strip of roofing that it is connected to. Add either a separate tile, or a new strip by laying it down in the area you have just removed. You should be able to nail this back down, and then add some caulk or roofing tar around the nails to prevent water penetration.
Step 5 - Finishing Off
When the tiles have been fixed, it is a good idea to paint over the surface. This will disguise the fact that you have a new shingle or patch on your roof, and will also help to protect your fiber cement roofing from water penetration, particularly when the roofing tar has just been added. Use a paintbrush to add the paint, and then allow it to dry thoroughly.