Alright – I will not lie to you: garage roof repairs should be done just as thoroughly as if you were fixing your grandmother roof. But sometimes you just have to move fast, without rolling out the entire construction circus. Maybe a shingle blows off the roof the day before you go on a two-week vacation. Can you fix that in a hurry? Sure you can – here are a couple of tips to get you through a tight spot.
Lets us say you have an asphalt shingle roof. For some reason one of the ridges are missing from the top of the roof one morning, and the plywood decking, as well as the volatile line where the two fields of roof meet – are exposed to any and all sorts of weather. What to do? Even if you do not have any spare ridges in store (and you should have, so shame on you) you can still do something. Get a piece of heavy duty plastic – like a tarpaulin – and lay it out over the exposed spot. Make sure there is plenty of overlap, as what you want is for any rain water to drain off the plastic with out any chance of creeping under it and soaking the plywood. You will have to decide how to make sure the plastic holds on the roof for as long as it takes you to arrange a proper repair. Nailing it around its perimeter could be a way, but then you will also puncture the undering shingles, ruining their ability to repel water to some degree. Replacing a few shingles is still cheaper than replacing a sheet of rotten plywood, so it may be worth it after all.
What if you have a different kind of roof, like a felt roof? If it is a pitched roof, you could try the trick with the tarpaulin, but be careful how you secure it – if you put holes in the roofing felt, you will only give yourself more work to do. If you have a felt roof repair kit handy, you could actually do a decent repair pretty quickly, especially if the leak is small. The problem is, it can sometimes be difficult finding the leak, as most felt roofs are laid out on plywood decking. This of course means you often will not see the leak until it has soaked the plywood enough to severely damage it. Water may be running downwards from the leak – sometimes even slightly sideways, so if you see rot or mold at the bottom of the decking (looking from the inside) the actual leak may be located higher up on the roof. The problems involved in felt roof repair, means it is usually not just a small job – also the roof may be structurally weakened if the decking is rotten. This could make it potentially dangerous to work on. No wonder it is usually recommended to put on two layers of felt, when doing a roof with this material.
Flat roof repair is potentially tricky to do, since mostly a flat roof is also an asphalt roof / felt roof. Here, you can not just put a tarpaulin on it and come back a week later – not easily at least. I have once had to simply drill a hole at a low point of a flat roof where a leak had sprung. This allowed the rain water to drain through the decking and into a bucket beneath, instead of soaking the whole construction itself. When I had time to fix the roof properly a few days later, the decking was actually drier than before I drilled the hole. Damage control at work, I guess.
This was a short lesson in "guerrilla roof repair". It will not produce any kind of permanent results, but may be used to reduce damage if you are in a hurry. Do not forget safety – never walk on an area of the roof which you know to be rotten or unable to support your weight.