I was going to re-roof my garage this summer, replacing the old corrugated bitumen sheets with something better. However, the combination of a dismal summer and an injury have prevented this. Now my garage is leaking more than ever and I need to do something temporarily until next Summer! I have a large heavy duty plastic sheet that will cover the whole roof which I want to secure to the bitumen sheeting so that it stays in place in the Cumbrian weather. Any advice on how I can do this would be appreciated. The roof is pitched in case that matters.