Extending Floor in Mobile Home

[AC]

I have a 30 year old mobile home with a bay window. The bay window is sagging now and we're going to yank it out. What I would like to do is actually extend the floor the 22 inches out to gain a bit of space.

The floor joists in the mobile home run vertically down the length of the trailer, so what I was thinking was just to take 8 foot 2x6s and sister them on to the existing floor joists, with six feet joined to the existing joists and then about 2 feet (well, 22 inches) hanging suspended.

What I want to know is whether this is a viable solution. Some people I've talked to say that I should really be pouring a proper concrete footing if I want to extend out past the frame of the trailer, while others think that what I've come up with, if using proper hangers and bolts, should be more than enough to support the floor above.

[Joseph Meehan]

I agree with those who say put in a foundation. What you are suggesting is likely to twist the frame and that could be the end of that 30 year old mobile home.

[spamTHISbrp]

22" wouldn't put much of a moment-arm on the frame, but how strong the frame is, is the real question. 2" C- section? 4"? 6"? Supported at the wheels and the hitch, or jacked-up around the perimeter in various spots?

I'd say 22" doesn't seem like much of a gain, and if putting a footing in IS an option, can you make it a lot bigger than 22"? Build as big as you can get away with, and can afford.

-Dave

[SQLit]

22" sounds do-able. Real question is what is going to be supported by the extended support. Have you considered the amount of space your going to loose in the 22" for the new wall? ( at least 5 inches )

You do not mention the spacing of the 2x6's. When I built my patio cover I went with 2x8's cause I could extend farther and wider spacing. 18" spacing instead of 12", in my application.

[Red Neckerson]

all yew need is some cinder blocks and some plywood. Yew can git them at any construction site....

[AC]

Well, I know for certain that there's going to be vinyl windows, and maybe a chair or something like that. We're not going to put a weight lifting kit there or anything :-)

The spacing is 16". I couldn't use 2x8s because the metal frame sits below. So I'm limited to 2x6s.

[Colbyt]

How wide is the center section of the bay?

I agree you can do it without a foundation and get away with it. I am not convinced that teeing off your existing joists is going to be enough support. Generally a canter-levered floor must have a lot of joist behind the extended portion.

Colbyt

[spamTHISbrp]

6' is the overlap he's anticipating! Quite a bit. D

[AC]

It will be 12 feet wide.

[AC]

One of the biggest reasons I was trying to stay away from footings was if I ever wanted to move or sell the mobile home. If I make modifications that require sticking something in the dirt, then the mobility goes away, or at least means tearing out or finding some alternate means of support for the extended floor.

[Colbyt]

I really don't think that is going to work using just hangers and such. More than likely you can manage to do it without sticking anything in the dirt but anytime you add on to a MH you lose the ability to move it. The cost of moving anything over a few years old generally exceeds the value of the home anyway.

If you want some advice on how you might add on in a non-code compliant manner just respond to this post. My grandparents lived in an old MH in a county without building inspection. I learned a lot of cheats over the years keeping a roof (literally) over their heads.

Colbyt

[AC]

Will 22 inches and windows put that much strain on the frame?

[Joseph Meehan]

On a 30 year old mobile home? It would be a concern to me. Especially when there is an alternative.

[AC]

I'm not too sure what the measurements on the frame are. I know towards the back where the wheels go (there are no wheels now) it is double framed. The frame itself seems pretty darn hefty and is in good shape. The trailer is supported by eight piers (cinder blocks) on concrete pads, so it's pretty firmly placed.