How to attach 2x4s on end for raised floor?

[mariannf]

Hi all, I am starting a 5x10 build on an HF 4x8. I have seen folks indicate that one way of doing this to avoid wheel wells is to start by joining 2x4s on end to the trailer frame. My question is how are the 2x4s attached? I can think of two ways. The first start from the top and put a lag bolt through the top edge of the 2x4 and through the pre drilled holes in the frame then secure with nut from inside the frame Chanel. Or starting from bottom and use a self tapping screw from inside the frame Chanel through the pre drilled holes into the 2x4.
Please let me know what you think is the better approach or if there is another way all together.
Thanks you all!

[KCStudly]

I like the way jseyfert3 did his using 1x4's and hurricane ties. http://www.tnttt.com/viewtopic.php?p=1063803#p1063803

[mariannf]

Thanks for this link KC! There is so much in the site! I like how the 1x4 will save weight.

[rowerwet]

I built my first tear with 2x4's on edge. I ran a sheet of 1/4" ply under them glued each beam on then laid the floor over the 2x4's also fully glued.
The biggest problem you will have is weight, 2x4's are way too heavy for a tear. 1x4 Or even plywood vertical members fully glued top and bottom would not give such a weight penalty.
Plus the space could be used as underfloor storage.

[mariannf]

Thanks Rowerwet. How did you attach the ply/2x4 subfloor to the frame of the trailer? Bolts from the top down through or screws in from the trailer on up into the wood?

[rowerwet]

Four bolts through the floor, vertical wood, sub floor and frame. One for each corner. Any more is overkill.

[mariannf]

Four bolts through the floor, vertical wood, sub floor and frame. One for each corner. Any more is overkill.

Thanks that helps.
One mire question do you attach each component of the floor sepeartely (2x4s to trailer, then ply floor on 2x4s) or did you build the floor and then attach the whole thing to the trailer frame?

[KCStudly]

If possible, build the floor on a bench of other flat surface... and IMO, you should build the cabin on the floor before attaching it all to the trailer. The trailer can get in your way while working and may not be flat or square. It is easier to get things tight and square working off of the bench.

Some shop situations may not allow for this, but it's what I would do (am doing) if I could.

[mariannf]

If possible, build the floor on a bench of other flat surface... and IMO, you should build the cabin on the floor before attaching it all to the trailer. The trailer can get in your way while working and may not be flat or square. It is easier to get things tight and square working off of the bench.

Some shop situations may not allow for this, but it's what I would do (am doing) if I could.

Thanks again for this help! i appreciate it.