Repairing Roofing Felt
There are a number of problems that can potentially occur with any felt roof. Use this as a simple guide to what problems you may face, and how you can simply fix them yourself. If you are having any serious troubles then it is always recommended to hire a roof contractor to do the job for you.
Cracks in the Felt
You should inspect your roofing felt to see if there are any cracks or splits in the surface. If you do find some, but the surface is still relatively flat, then this should be simple to fix. Repair the cracks by using a bitumen spread over the area of the crack, or you can choose to use self-adhesive repair tape.
Before making this repair it is important to make sure that the area is cleaned and that there is no debris in the way. If so, it could decrease the effectiveness of your repair and reduce the seal on the surface. Once the repair is in position then you should apply extra material to the surface to seal it completely. You should try to find a material that reflects sunlight in order to protect the felt.
Bubbling in the Felt
If you have found cracks in the roofing felt that are also showing signs of bubbling then there is the risk of water seeping through the surface. In order to rectify this you should cut a hole in each bubble in the shape of a cross to allow them to dry out, as bubbles mean that moisture has built up under the surface.
Once all of the bubbles have dried out you should use a bitumastic compound as a way of getting the felt back in to position. Again, you will need to apply more material to the surface in order to seal the area completely. If you also cover it with a chipping compound that matches the rest of the surface then this will help to strengthen it more.
Dampness
You may not have found cracks or bubbling in your roofing felt, but there could still be signs of dampness showing on the ceiling below the area. If this is the case you should check the flashing. The flashing strip should be completely watertight, but it can sometimes come away from the wall which it what causes the water to seep through.
To repair this problem you should take the flashing strip off, clean the area below and use a ready mixed mortar to fix it back into position. You will then need to re-point the joist.
Conclusion
Most of these common problems with roofing fixed can be fixed with a simple DIY repair. The products required to make the repairs should be easily available in DIY stores. However, if there is more substantial damage then it may be worth seeking professional advice.

