Expert: Richard Taylor, AIA - 4/21/2006

Question
Hi!
I'm building a 45'deck along the back of my house and want to add a roof extension to cover it. Kinda like an old fashioned covered porch. The existing roof ends too low to get a good pitch on the deck roof, so I would like to start the extension further up on the roof. How do I attach it and what kind of problems do you think I will have? Or am I crazy? Or do you have other ideas?

Answer
Hi Anna - thanks for your question!

The big "shed" roof you're talking about is going to cause you all sorts of problems (just what you wanted to hear, right?).

First, it's very large, so it's very heavy and very expensive.  You'll be putting a significant load on your existing roof that it probably isn't designed to handle.  You'll also have to tear up the existing roofing to flash the new roof into it.  Messy and expensive!

I'd suggest covering only part of the deck, an area just large enough to protect a table and a couple of chairs.  Then you'll still be able to sit outside in the rain, and you'll still have a large sunny deck when you want it.

If you do that, you can put a "reverse gable" roof over the covered part of the deck and tie it to the existing roof much more easily (and for less $$).

Alternatively, you could move the whole deck structure away from the house a few feet and put a free-standing roof over it - then connect it to the house with a covered walkway.  That completely avoids the problems with attaching the big roof to the house!

Either way, it's a big job and you probably should have a design professional's help.  Check with your local AIA office (look them up at www.AIA.org) for a residential architect in your area.

Hope this helps!

Richard Taylor, AIA
Richard Taylor Architects, LLC
www.rtastudio.com
www.betterhouseplans.com