Solving those pesky rainwater problems

Q. My 50-year-old house has two problems which arise from the heavy rains: * The garage at the foot of a slopping drive receives water runoff which collects on the slab floor. What is the best way to divert this runoff? Should I make a depression in the front of the driveway or put in a drain of some kind?

* There is a leak in the asphalt-shingle porch roof. I can see no holes or gaps in the shingles. How can I find the leak and stop it? Ben Shulman Los Angeles

A. Either of the two methods you propose might intercept the water or drain it away, depending on a good many facts at the site which cannot be known to me at this distance.

I would suggest you try to deflect the runoff before it migrates to the garage. Can you handily develop a dam or drain so as to keep the water entirely away from the garage? Go that route if possible and practical.

If the project is completely over your head or beyond your interest to do yourself, then ask for help from a good handyman or small local contractor.

* As far as the clandestine leak in the porch roof is concerned, my guess is that the roof of the porch is a lower pitch than the main roof of the house. If that is so, then check the condition of the shingles where the mainroof changes pitch to the lower porch roof. You may then need to install some kind of metal or composition flashing at this vulnerable intersection.

If the porch roof and the main roof are the same pitch, then pick a dry day and squirt some water from a garden hose on the roof until you find the holes or cracks. Replace the damaged shingles or repair any holes with an [*] asphaltic roofing cement.

Sometimes you can slip some thin metal shingles up under the asphalt shingles to stop the leaks.

Short of finding and fixing the leaks yourself, call in a local roofer for help. Roofers are pretty shrewd at stopping leaks.