Cut a piece of new felt to use as a patch big enough to give above a 50mm 2 inch overlap beyond the repaired blister.
How to fix a flat roof with felt.
For older felt roofing a patch of torched on roofing with add an additional layer and fix the damage.
Cover the edges of the roof with strips of felt before laying out the final layer.
Fibreglass flat roof repair.
Step by step guide for felting a flat roof step 1.
Press the patch firmly into place and make sure that the edges are well sealed.
Apply some bitumen adhesive over the repair and beyond to suit the patch and apply it.
Fill the hole with a layer of roofing cement.
You will follow the same process as in step 2 for the last layer.
You can cover the surface of the felt with gravel for added strength.
You must remove any rotted pieces of wood on the roof and replace them with your plywood.
If the old layer of felt roofing is in good enough condition then a liquid system repair can be applied.
Get a can of a waterproof roofing cement from the store.
Please ensure that the user of a torch flame to conduct repair work on felt roofing is insured to work with naked flames and always have a readily available and easily accessible fire extinguisher to hand.