building deck/floor up off the frame

[d_lairson]

I'm thinking of using a HF 4x8 for my 5x8 build. I know I'll have to make room for the tires but would there be any difficulties building the frame/floor/deck up several inches from the trailer frame. I don't know if i'm explaining this right but see if you can follow...

If the floor frame is built on like 2x2's with a 1/2' ply on top bolted to the frame could you build it with 2x4's with a 1/2' ply on top with the 2x4's on the long edge so the deck/floor would be 3.5' (plus a 1/2 for the ply) off the trailer frame instead of only 1.5 (plus ply). This would give me an extra couple of inches to clear the tires and lessen the impact on the sleeping area.

I guess the question is, if I can do it (I mean I know I could do it) would it be safe and could I get bolts long enough to go through the ply-2x4-frame?

Thanks, and Cheers,
David

[Nobody]

Would it be safe & can you find bolts long enough, yep on both counts. I guess a lot depends on how high you want your floor & door sill(s) to be off the ground, & whether your springs sit above or below the axle. The HF 1740# trailer frame sets approx 14" from ground to bottom of chassis & the 5:30x12 tires extend approx an inch above the top of the chassis with springs on top of the axle (normal configuration). Most folks don't want the door to be much higher than would be comfortable to sit in the doorway with feet touching the ground (I'm short so that don't really work for me but then I don't do a lot of sittin' in the doorway either ). I built my floor from 2x2" (actually 1 1/2 x 1 3/4", ripped 2x4's) that are set on the 1 1/2" dimension). Covered with 1/2" plywood that put my floor 2 1/4" above chassis level. I had to construct shallow wheel wells to allow for spring flex. I did a lot of careful measurement & experimentation before deciding on the final design/dimensions of the floor/wheel wells. I actually loaded more'n 1200#'s of junk (concrete blocks, scrap steel, & yeah, even the kitchen sink ) on the bare trailer chassis to determine the amount of flex (depression) of the springs. Turned out it was negligible so I planned the wheel wells to leave around 2" clearance above the tires. The wheel wells then intruded only a little more'n an inch into the cabin. After towing the completed TD more'n 6K miles I was still a little ucomfortable with the clearance I'd allowed. I'd been over some pretty rough roads & the tires never contacted the underside of the wells but I sometimes carry a pretty good load in the cabin & galley so I installed a 1" thick steel spacer on the spring seat between the axle & springs, just for my peace of mind . The bottom of my trailer chassis now sits 15" above ground & my doorway is around 23" above ground level (that's with a 3" 'lip' at bottom of doorway to contain mattress, bedding etc). Here's a few pix with more detailed ones in pages 18-22 of my album -

testing 'flex' of springs on laden trailer


framing up the wheel wells


floor frame w/wheel wells integrated


completed floor showing wheel wells extending above floor level


this pic shows the floor attached to chassis with 10 carriage bolts, & a better perspective of how much the wheel wells intrude into cabin - the galley bulkhead when installed, abutted the rear edge of the wheel wells

[aggie79]

Great discussion and pictures Harvey. I've seen your teardrop and it is very impressive.

I think Harvey's photos show an importent consideration of a deeper floor. That is his use of a skirt to cover the extended height. You'll probably need to do likewise if you are using standard 4x8 plywood. If you just used the plywood to cover the framing, your headroom might be a little snug.

Tom

[Lou Park]

I can only guess that your axle is under your springs. A lot of guys try to lower the entire frame by mounting the axle over the springs therefore lowering the body as well. I'm sure the way your doing is will work just fine.
Lou