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Tiny house on a 16' trailer

Wisconsinite's picture

Tiny house on a 16' trailer (post #207577)

Hello,

My sweetheart and I are building tiny house on a 16 foot flatbed trailer. The interior we want would fit a lot better in an 18' house. How far can we safely overhang the floor off the back of the trailer?

If the section behind the wheel wells had its 2x4s running front-back instead of side-side, could they support it?

The whole rig will be in the neighborhood of 6,000lbs.

Thanks for your time!


Two feet isn't that much, so (post #207577, reply #1 of 13)

Two feet isn't that much, so you could probably just stiffen the sides and rim joist to support it.  Or perhaps use a diagonal cable (inverted V) to support the end.  Or steel diagonal strapping similarly oriented.

Another option is getting a welder to extend the frame.


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Contrary to engineer Dans (post #207577, reply #2 of 13)

Contrary to engineer Dans advice you can not cantilever 2 X 4s two feet, They don't have enough bending strength to resist that much force. As long as you don't plan to actually move the trailer much you could probably have some steel tubing welded up that would work. But, it would make more sense to have an18' trailer made or to extend the one you have by two feet.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

I never said anything about (post #207577, reply #4 of 13)

I never said anything about cantilevering (unsupported) 2x4s.


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Welding (post #207577, reply #3 of 13)

We are considering extending the trailer, but it would be nice to solve this with lumber. My go-to welding shop has mysteriously gone out of business.

It will certainly be pulled around, so it needs to be resilient.

What about 4x4s?

Thanks!

4x4s are, at best, twice as (post #207577, reply #7 of 13)

4x4s are, at best, twice as strong as 2x4s, and probably not sufficient.

My suggestions (before being misinterpreted) were:

  1. Use something substantial to stiffen the rim joist.  Heavy-duty steel studs might work, or you can increase the height of the back 8 feet or so of the rim joist to maybe 10" (remember, the floor joists do not need to be flush with the top) and use microlams or whatever.
  2. Apply plywood to the sides of the structure -- probably a 4x8 foot piece, 1/2" thick, running "on its side" from the back corner forward.  The bottom edge of the plywood should lap the rim joist and be firmly attached to it.
  3. Run a cable or strap (on each side) from the back corner diagonally up to the top of a doubled stud and then back down to an anchorage point in the trailer frame.  The cable/strap would need to be firmly anchored at both ends.  A cable might be run through holes drilled in the intervening studs.  The strap would ideally be a T-strap cut into the sides of the studs.
  4. Have a competent welder extend the trailer frame.

In any event, the 2x4 floor joists will need to be well-anchored to the rim joist and whatever other support you devise, using good quality joist hangers or the equivalent.


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Thanks Dan, It seems like (post #207577, reply #5 of 13)

Thanks Dan,

It seems like option 4 is the simplist solution.

I was hoping someone would say "Nothing worry about, double up the 2x4s, you'll be fine".

Oh well, time to find a welder.

Trailer floor frame (post #207577, reply #6 of 13)

Hey there Wisconsinite,

    Here's an idea for your trailer/home floor frame.  Frame the floor in 2 sections.  The hitch end that doesn't need the cantilever is simply an 8' section with joists running the length of the trailer, not across it.  The second section is an 10' section with 2' cantilevering beyond the trailer frame.  You will need to use 2"x8" for all the floor frame or a slightly smaller LVL if height is an issue.  Double up the cantilevered rims if you really want to stiffen it up.  I'm assuming this is a single story home, if not watch out for those low bridges when you hit the road!  I included a quick sketch to show you what I was thinking.  Hope that helps.  

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Thanks for all the helpful (post #207577, reply #8 of 13)

Thanks for all the helpful suggestions.

It seems like there are ways to do this with lumber, but we are going the welding route.

I found a welding shop that quoted me $300 to add 2' of trailer deck. This trailer is the foundation of the house, so it make sense to have enough of it to hold up the whole house. We might add 3', but any more than that will shift the ballance towards the back (and off the hitch).

Hitch issues? (post #207577, reply #9 of 13)

Not being a trailer expert take what I ask or say as you like.  I would be afraid that by adding two feet out the back your hitch uplift might get funky.  Yes?  No?

.

Put your water tank, heavy (post #207577, reply #10 of 13)

Put your water tank, heavy appliances, etc as close to the hitch as possible, bedroon at the back, etc... 

Well, you don't want it (post #207577, reply #11 of 13)

Well, you don't want it hitch-heavy either.  The usual rule is 60% in front, 40% in back, taking into account lever arm. 


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Yes the usual rule is 60% (post #207577, reply #12 of 13)

Yes the usual rule is 60% front and 40 % back but ot also depende on your needs and power of your trailer. I have no experience about trailer home you need a expert for your issue.

 

Solution (post #207577, reply #13 of 13)

I just got the trailer back. We had the deck extended 3 ft, but instead of adding in the back he chopped it just agead of the wheels and spliced in a section there. That gives us the length we want without making it back-heavy.

 

Thanks for all the input!