Tips on the Roofing Repair of Leaky Flashing
The first thing you need to do is to find the flashing which is leaking, this can be done by raising a few shingles to see if the nails holding it are loose or missing. If this is the case, simply re-anchor the material, but using new nails is not something we, at APEX Roofing & Construction in Santa Fe, TX, recommend. A better choice will be to screw the flashing down – try to match the screws to the same material your roofing flashing is made from. Then, cover the screws using a waterproof substance like silicon.
Roof flashing can develop holes, over time, usually due to severe hailstorms. If you locate a hole, cut out a patch from any extra flashing you have, and thoroughly clean and smooth the area that is around the hole. Always make sure the patch you cut is slightly bigger than the hole, and then glue it with roofing cement. Once this has cured, it is advisable to apply another layer of roof cement on the patch. Regarding roofs, there is no such thing as overkill when performing a roof repair job.
Flashing which is around chimneys and vents, however, is another story altogether. When these pieces have broken off, it is mostly because the seals holding them in place have rotted or been damaged. Remove the old seals, thoroughly clean and remove any debris, and use either caulk or roofing cement. Reinstall the flashing to the original position, and hold or clamp it until the seal has completely cured.
If none of the above work and you are still experiencing a leaky roof, then your problem is not with your flashing. In such cases, it is likely you have worn or damaged shingles. Your options then will be to seal your entire roof with roof tar or cement, or failing that, you will need a completely new roof.