IS YOUR felt shed roof leaking? If only a small area of the felt is damaged you can patch it up. If water has been getting under the felt for some time you might need to replace it and some of the roof boarding below it.

1. Check over the surface of the felt looking for damaged areas. If you find a holethen a new patch of bituminous felt, a tin of cold roofing felt adhesive and a tin of wood preserver are what you need. If there is a lot of damage or you can't see any holes then it is time to replace all the felt and check the boarding below it.

2 Wait for a dry day. Use a craft knife to cut away the damaged roofing felt - try to take off about 7cm around the area that was damaged. Check the timber roof boarding below for damage - it may have started to rot. If it's OK, saturate the exposed area with preservative and leave to dry. If it is damaged, judge if it is time to replace all the felt and repair the boarding as number 4 below.

3. For the patch, cut out a piece of felt which will cover the trimmed area and overlap it by 10cm all round. Lay the patch over the hole and mark around the edge with chalk. Take away the patch and coat the marked out area with adhesive. Once it is time ( check the instructions on the adhesive) press the patch firmly onto the adhesive. Try to smooth outwards from the centre to prevent trapped air bubbles.

4. If you need to replace the roof covering, first tear off the old felt and remove any nails with a claw hammer. If any of the boarding below is rotten or damaged use replacement timber which has been cut to size, saturated in preservative and left to dry. Fix the new board in place with galvanised screws. Treatany undamaged original timber with preservative also.

5. Cut the new felt from the roll with a sharp knife. Measure off strips of felt long enough to run parallel with the ridge and lap over the edges by about 5cm. Start with the lowest edge of the roof and work upwards. Use galvanised roofing nails to fix the felt along the top edge and to hold down the overlaps at the bottom and sides. Brush adhesive along the top edge of the felt ready for the next piece to overlap 15cm onto it. Press the bottom edge of the next strip of felt onto it and so on. When you reach the top, trim a strip of felt to the width you will need. If you have a single slope roof lap the felt over the top edge and nail it down.For a pitched roof, felt both slopes first then fold the last piece over the ridge. Use adhesive to fix both sides.

Jeff Howell