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How did you widen your trailer.?

PostPosted: Sat Jun 06, 2020 1:58 am
by 30dayreviews
I have a trailer now that was a popup that had been turned into a flatbed. well now im wondering since the middle rails that go from to back are only 4.6 apart how do you usually combat the issue of it not being 5ft wide with a beam under the edges or what would your suggestions be? thanks for any help given in advance. oh and the back will be stretched as well to be an end trailer of 5x10162178

Re: How did you widen your trailer.?

PostPosted: Sat Jun 06, 2020 3:57 pm
by troubleScottie
Search for "overhang" on the site. Lots of examples and suggestions.

Also look up ideas on attaching the floor to the trailer. You might need more cross bars.

To overhang, the floor needs to be strong. Typically, a "torsion box" which is 1/4" plywood, 1x2 framing around perimeter and cross pieces and 1/4" plywood on top, screwed/glued together. Rigid insulation makes the floor more stable for putting weight on it. Half inch plywood would still be stronger. But most people would consider it overkill if you are not walking on the flooring.

Another thing to remember, the floor might be hitting things eg brush. The advantage of the frame extending to the edge of the cabin is the frame is protecting the cabin.

Assuming your 4.6 is 4' 6", you are looking at a 3" overhang on each side. Not particularly large.

Similarly, you could have overhang aft and stern if you need more length.

Just a point on the width. 5' inside width is a good size. So the floor would be wider ( > 5') to have the walls attached on top of the floor. Make sure you have enough width for placement of anything you might put in the galley eg cooler/refrig/freezer, sink, stove/oven, water containers. Remember any space needed for a roof edge water barrier assuming a galley roof. Adding a few inches is not that hard.

If you are covering the TD in aluminum, confirm the width of the material. That might make the trailer box width limited to 5' including the walls. So a narrower inner floor width.

Re: How did you widen your trailer.?

PostPosted: Sat Jun 06, 2020 5:02 pm
by MickinOz
I built a frame from 70 x 35 mm (about 2.75 x 1.5 inches) treated pine, and screwed and glued the floor sheets to it.
Some see it as over built, but it has to support everything including my fat ass whilst sitting only on the two longitudinal frame rails. Like yours, they are 4' 6" apart.
It's single skinned too, so there is no torsion box effect.

The torsion box is a good way to go. Personally though, I'd look at putting the 2 x 1 on edge, i.e. the 2 inch face would be the vertical face.
I just think that having two inches between the two 1/4 inch sheets should improve the strength over only having them 1 inch apart.
The other thing I'd do differently - I used screws to fix the sheets to the frame. Expensive over kill. Glue and staples next time, I think.

Re: How did you widen your trailer.?

PostPosted: Sat Jun 06, 2020 5:07 pm
by MickinOz
troubleScottie wrote:Adding a few inches is not that hard.

A few inches wider is quite simple, though it causes some wastage of materials. (Can't get 5 x 5 plywood here.)
Anything over 8 feet long is a pain in the butt though.
That's frames and joins and stuff. Still not hard, but very time consuming.

The other thing is, when you extend the width, you generally either have to build in wheel wells, or get a longer axle so your wheels clear the body properly.
Over here in Oz, I got a longer axle that wasn't super expensive, but did add maybe 5% to my costs.

Re: How did you widen your trailer.?

PostPosted: Sun Jun 07, 2020 12:17 am
by 30dayreviews
troubleScottie wrote:Search for "overhang" on the site. Lots of examples and suggestions.

will do!

Also look up ideas on attaching the floor to the trailer. You might need more cross bars.

thinking of having a welder add 6-8 tabs to bolt to

To overhang, the floor needs to be strong. Typically, a "torsion box" which is 1/4" plywood, 1x2 framing around perimeter and cross pieces and 1/4" plywood on top, screwed/glued together. Rigid insulation makes the floor more stable for putting weight on it. Half inch plywood would still be stronger. But most people would consider it overkill if you are not walking on the flooring.

Since I want to insulate and maybe add a storage box under the trailer this is kinda what I was thinking about doing anyway. I was thinkiing 3/4" for teh bottom and 1/2 for the top but I sopose as long as I put in enough joists that would not be needed.

Another thing to remember, the floor might be hitting things eg brush. The advantage of the frame extending to the edge of the cabin is the frame is protecting the cabin.

this is what I was worried about, however as you stated 3 inches on each side really isn't that much. I may also be able to find some mettle to attache somehow to the bottom edges to help protect that.

Assuming your 4.6 is 4' 6", you are looking at a 3" overhang on each side. Not particularly large.

Similarly, you could have overhang aft and stern if you need more length.

Think I only want to go back and The back needs to be redone anyway so figure might as well just have it done right.

Just a point on the width. 5' inside width is a good size. So the floor would be wider ( > 5') to have the walls attached on top of the floor. Make sure you have enough width for placement of anything you might put in the galley eg cooler/refrig/freezer, sink, stove/oven, water containers. Remember any space needed for a roof edge water barrier assuming a galley roof. Adding a few inches is not that hard.

I may have misspoke. I am thinking 5 wide total. this would give me about a 4'8" interior once the 2" (dimensional) walls are in.

If you are covering the TD in aluminum, confirm the width of the material. That might make the trailer box width limited to 5' including the walls. So a narrower inner floor width.


I am thinking about actually trying to get ahold of luane i think its called.

Re: How did you widen your trailer.?

PostPosted: Sun Jun 07, 2020 11:07 am
by GuitarPhotog
It's called Luan. It's a mahogany that is commonly used in 1/8-1/4" thickness so it can be bent.

<Chas>
:beer:

Re: How did you widen your trailer.?

PostPosted: Sun Jun 07, 2020 11:08 am
by OP827
30dayreviews,
For constructive technical argument, I am not convinced that a torsion box is warranted over your frame unless you plan on putting some heavy weight on this floor. This looks like additional weight and time and cost.. and then potentially added height. Your original popup trailer most likely had just 3/4" OSB or plywood for its floor, like my build popup donor trailer had with similar frame and cross members dimensions (photo in my album). I saw people building their trailer using a house sized materials and then are surprised with the build final weight being heavier than expected, but then it is usually too late or very hard to correct. I went with 5/8" SPF construction plywood, two small stiffeners under traffic zone and epoxy coating on both sides (in my album)

As for the overhang for the floor, if you still can get minimum 1-1.5" clearance between your tire and the finished wall without changing the axle and frame then up to couple inch floor overhang should not be a problem. In my build I did 1 inch overhang to have more space inside to sleep across the trailer, but I did not cut any framing from the popup frame and had to build wheel wells. Are you going to cut off all the steel framing outside of 4'-6" frame? Do you have a design sketch of your teardrop? Good luck with the build!

Re: How did you widen your trailer.?

PostPosted: Sun Jun 07, 2020 12:33 pm
by 30dayreviews
GuitarPhotog wrote:It's called Luan. It's a mahogany that is commonly used in 1/8-1/4" thickness so it can be bent.

<Chas>
:beer:

the stuff im looking at is a plastic though and not a wood.

Re: How did you widen your trailer.?

PostPosted: Sun Jun 07, 2020 12:57 pm
by 30dayreviews
OP827 wrote:30dayreviews,
For constructive technical argument, I am not convinced that a torsion box is warranted over your frame unless you plan on putting some heavy weight on this floor. This looks like additional weight and time and cost.. and then potentially added height. Your original popup trailer most likely had just 3/4" OSB or plywood for its floor, like my build popup donor trailer had with similar frame and cross members dimensions (photo in my album). I saw people building their trailer using a house sized materials and then are surprised with the build final weight being heavier than expected, but then it is usually too late or very hard to correct. I went with 5/8" SPF construction plywood, two small stiffeners under traffic zone and epoxy coating on both sides (in my album)

As for the overhang for the floor, if you still can get minimum 1-1.5" clearance between your tire and the finished wall without changing the axle and frame then up to couple inch floor overhang should not be a problem. In my build I did 1 inch overhang to have more space inside to sleep across the trailer, but I did not cut any framing from the popup frame and had to build wheel wells. Are you going to cut off all the steel framing outside of 4'-6" frame? Do you have a design sketch of your teardrop? Good luck with the build!


I dont think I mind the torsion box as I want to insulate it anyway on the floor. I live up here in North Dakota so we have a very short summer and are colder more than not.
I want to get larger tires on it as I would like at least car-sized tires and since I will have to move there location anyway figure I might as well get a new axle and put some springs under it to help with a little extra hight. I have an idea of what I want but until I get the frame specifics figured out I don't want to get into the nitty-gritty details of ideas.