[butlerbach]

I am in the planning stages of building a deck with a screened porch. The deck will be free-standing, so my question is this: Can I tie the roof of the screened porch into the existing roof of a cantilevered section of the house? Anyone??? I'm lost here.

 

[Just Bill]

If the deck is not attached to the house, nothing else attached to the deck can be attached to the house. Did you get a permit for the deck?? Decks are carefully regulated for good reason. A deck without a roof is one thing, but with a roof it becomes a room and all the rules change.

 

[butlerbach]

Thanks for the reply. No I haven't obtained a permit for this yet....I'm still in the planning phase (trying to get all the kinks worked out before I start.....learned this the hard way in the past). I was fearing that I would get the answer you provided. This means I will have to find an "approved" method to attach the deck to the ijoists in the cantilevered section of the house. I'm not sure what the county's take on this will be, but maybe they will cut me a little slack since its only a 2' cantilever sitting on the foundation. But in the meantime, if you happen to have any good ideas for a non-leaking, non-attached roof that could sit on top of the catilevered section's shed-style roof.......(is that permitted?). Anyway, greatly appreciate your response.....even though it's not the answer I "want to hear", it pushes me in the direction I need to go. Thanks.

 

[Scuba_Dave]

The most common roof I have seen over unattched decks is a rubber gasket between the roofs. Not attached to both, but seals the gap. Attaching to a cantilever on the house adds to the strees on that cantilever. Many were not designed for added weight of a deck. Why not just support it at the house & attach to the house?

A pic of the area on the house would help

 

[butlerbach]

Do you have any photos of the rubber gaskets used for connecting unattached roofs? I don't have any photos of the area at the moment, but I made a quick diagram of the basic setup. If there is a way to use rubber gaskets that will basically seal everything off so that no water comes down the existing roof and into porch area, that would be great (I have never seen this anything like this before).

 

[Scuba_Dave]

I would be inclined to put a concerete footing under the cantilever
Then put a 4x4 post supporting the cantilever
If the catilever is close to the ground you could pour cement right up to the canti-lever
---making sure that there is PT between the concrete & cantilever wood
Then attach the porch to the house

 

[butlerbach]

Do you think the county would accept the concrete footing idea as a solution to the cantilever dilemna? It would have to be an entire beam underneath.....the cantilevered section is almost 19' long. Unfortunately, it is nowhere near the ground, the beam will have to be about 8' tall.....while that might not entirely rule out the idea of pouring cement right up to the cantilever, I'm thinking there are at least a few less expensive options. Where can I find information on the non-attached roofing process that you mentioned?....if the county doesn't approve of me tieing into the IJoists, I might need to use the non-attached rubber gasket method. At the very least, it sounds interesting.....would like to learn more about it.

 

[Scuba_Dave]

I'm sure you could pour cement at ground level & then put in support posts & a beam
I guess you can't tell how long the joists are that support the cantilever?
Properly supported NEAR the house the deck should not put any significant load on the cantilever
I would suggest talking to your building inspector & running the ideas past them

 

[butlerbach]

The Ijoists sit on the foundation wall, spaced about 24" oc, extend approximately 2' into the 2'-cantilever, and at least 16' in the other direction to rest on another foundation wall......(at least this is what it looks like in the basement). I guess I could always add new floor joists over both foundation walls and extend them out to a beam at the end of the cantilever.......but I'm still not sure if they would consider this sufficient for attaching the deck.....not to mention it sounds like a bit of over-kill.

 

[VaViaCo]

From the drawing, the roof you want to tie into is short. Could the porch roof extend over top of that roof and tie directly to the house?

 

[Gary in WA]

Run some of this by your local Building Department.

A new foundation to support the cantilever would almost certainly have to be engineered. Especially with a basement 2' away. Most Departments will not let you attach a deck to a cantilever.

You may even have to hold the bearing beam back and cantilever your deck joists.

As Just Bill said, a detached deck with a roof is complex. Cannot attach to house.

Only your Building Department knows for sure, soil conditions, frost depth, etc. Be safe, G