Q&A OF THE WEEK: "How can I keep rain from coming through a second-floor deck?"

Updated on April 10th, 2021

By: Steve Maxwell

Q: How can I keep rain from dripping through a second-floor deck? I want to use the area underneath the deck for weatherproof storage of outdoor equipment.

A: That’s a worthwhile goal you have in mind and you’ve got a couple of options. My favourite involves building a verandah roof over your deck. Besides providing protection for items stored under the deck, the roof also makes your deck much more useful.

Covering a deck makes the structure much more useful. You still enjoy outdoor air, smells and refreshment, but you don’t need to worry about rainy days or too much sun.

If you want to spend less money or you don’t want to change the look of your house that much, sheet metal roofing fastened to the underside of deck joists makes a great, weatherproof ceiling for applications like yours. You can order it in whatever lengths you need to extend from the house wall out to a few inches beyond the edge of the deck. Fasten the metal with special roofing screws that have neoprene washers underneath the heads, with the factory-painted surface of the roofing facing down. For best results you’ll need to install this metal on tapered strips of wood that ensure a consistent slope away from the house for good drainage. You can direct the water to run towards the front or sides of the deck, whichever is more convenient. The only thing is that you need a deck that’s sufficiently high off the ground to work on underneath and to store and retrieve items conveniently from below.

30″ is about the minimum space you need underneath a deck to make it worthwhile creating a weatherproof “under-roof”.

Either way, overlap the seams one notch further than you would if the metal was installed in the usual way, just to make sure there are no leaks. You might also consider installing eavestrough around the perimeter to stop water from splashing onto things stored below. You should also consider blocking the area around the perimeter of the deck ceiling to keep out nesting birds and other animals.

Since you’re working on your deck you might find a video on outdoor project details useful. If you want to make your outdoor projects look better (in some cases even after they’re built), this video will interest you. Click below and see for yourself.