Maintenance important

Press, 27 June 1983, Page 27

Maintenance important

Correcting minor roof failures as they are discovered helps protect against major roof damage. Where the seals along flashings are starting to give way, apply new sealant. Where the guttering and downpipes have collected debris, clear them out. Most leaks begin at vulnerable points, such as flashing seals, cracked tiles, and valleys clogged with debris. To locate a leak, first examine the roof from underneath it, and mark wet spots with chalk marks. Having followed back to the source of the leak, run a piece of wire through the hole to mark the spot for repair from above. When the roof has dried out somewhat, inspect the upper surface and decide then on how best to make a permanent repair. Damp fibreglass batts will still provide effective insulation after being dried in the sun, but loose-fill insulation that has got damp should be replaced. Occasionally, rafters sag as a result of years of exposure to damp and then dry air, or become weak-

ened by rot. Where a rafter has absorbed excessive moisture because of inadequate ventilation or a leak, the ventilation should be improved, or the leak stopped. Once the wood is dry, apply wood preservative to protect it from further damage. Where there is rot, it may be possible to correct the problem with a coat of fungicide. If the wood is more severely damaged, dig out as much as possible of the spongy matter, and fill the hole with a plastic putty compound. A sagging rafter can be strengthened by sandwiching it between two supports. Using well seasoned timber of the same width as the rafter, cut two pieces long enough to extend at least half a metre beyond the damaged area at both ends. Fasten the first “sister” using nails long enough to penetrate the existing rafter as well, nailing it at 25mm intervals. Hammer down the protruding points before attaching the other support piece.