floor framing

[Grid Runner Adventures]

ok. i am gearing up to build the camper, the first part i got to make is the floor, it will be a 6ft wide camper on a 4 ft wide trailer. so 1 ft overhang on each side.

im planning on 1/8th inch ply and a 2 inch frame with 2 inch foam board insulation and what thickness of ply over that? 1/4?

should i use 2x2's for the floor frame or could i do 1x2

keep in mind it must span the 1ft on the sides to get up to 6 feet.

going to do the whole frame in lap joints.

[Ageless]

First, 2X2 are not 2", so 1 1/2" foam will work. Therwise you are in the ballpark

[Grid Runner Adventures]

how far of a spread should i do, place the framing over where the framing is on the hf trailer?

also how many stringers are needed. one down the center or should there be two rows of stringers.

[bobhenry]

I have a 5'7" out to out wide teardrop on a modified HF frame and I will give you my spin for what it is worth.

You are asking 3/4 "
(Think of that 1 1/2" x 1 1/2 " "2x2" cut 1/2 way thru for a lap joint)
of white pine to support the entire weight of the sides and roof and anything fastened to them in a 1 foot cantilever situation.

Your effort to save weight is commendable but this just ain't the place to do it.

On a harbor freight trailer the fenders and wheels stand 2 1/2" or more proud of the frame. There are 2 ways to handle this, bump ups or a deeper (and higher) floor. Even a 7/16 floor will require 16" on center support ( yes you can get by with less because you are dispersing the load over a mattress ) MAYBE ?

Mine had bump ups that measured 2 1/4 inches. Even with a serta pillow top mattress I only slept in it one trip with the bump ups under the mattress. They telegraphed thru and were uncomfortable so after the fact I added more weight by adding blue foam to level with the bumpup and a 7/16 sub floor over top. This proved to be a great way to insulate the floor and I do no regret doing it but if I had it to do again......

I would rip 2x4's to 3" and stand them on edge 2' apart. The 1/8 could still go on the bottom except at the wheel wells. Install insulation in all cavities for an insulated floor and top with 1/2" plywood minimum glued and screwed 4" on center. The addition of a rim board at each side will afford a place to fasten the exterior sides to. There are several styles of steel joint reinforements that will help strengthen the connection of your floor joist to the perimeter ribbon.





This is the foundation to your house it recieves the shock of each and every pot hole and lump in the road I would not choose to make this the place to save weight. Build this as a torsion box and black goop the bottom and then install it with 6 to 8 carriage bolts directly thru the 2x3 and into the frame. and double nut the connections for safety.

We are in the snow belt and need an insulated floor to extend our camping season. The folks in Florida and sunny california do not see our need but this works. Take a moment and start at the rear of my album and page forward 3 or 4 pages and see how a bent and damaged $75.00 HF frame can be used for a tear.

From a guy that has been there and done that for what it is worth !

[Grid Runner Adventures]

origionally i was thinking of using 2x4's and notching them down to 2x2 in the middle to fit over the trailer frame. that way when the ends flexed down the notched out portion would be supported by the sides of the frame. would make it a bit harder to skin the bottom side like that though. ie i would have to put a strip of wood on each side of the 2x4 overhangs that is inline with the 2x2 section to fasten the 1/8th inch ply too. its doable still and stronger then the 2x2 alone.

[alffink]

I'm in Sunny CA and I wholly believe in a fully insulated tear, but why try to box in the bottom of the floor, that would just create another place to trap moisture.

Now that you are building out beyound the frame to widen your tear you might want to look at the over hang as eves and build soffets to box in that partticular area, but under your trailer is a pretty well protected area.

Rain falls down not up, I am primarily a desert camper, graded somewhat dirt raods are the norm. I have pulled my tear though, sand, dirt, rain, mud, snow and of course our great highway system, pun intended.

I have well over 3,000 travel miles now, and the underside of the trailer is nearly as clean as when it first hit the road.

[Grid Runner Adventures]

[img]

this is what im building. it will be able to lift off the trailer so i do not loose having a cargo hauler too.

whole outside will be rhinolined

so you guys dont think that 1/8th inc with 2x2 framing stuffed with foamboard and 1/4 inch ply would be strong enough for the floor to span that 1ft on the sides?
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[bobhenry]

I'm in Sunny CA and I wholly believe in a fully insulated tear, but why try to box in the bottom of the floor, that would just create another place to trap moisture.

Now that you are building out beyound the frame to widen your tear you might want to look at the over hang as eves and build soffets to box in that partticular area, but under your trailer is a pretty well protected area.

Rain falls down not up, I am primarily a desert camper, graded somewhat dirt raods are the norm. I have pulled my tear though, sand, dirt, rain, mud, snow and of course our great highway system, pun intended.

I have well over 3,000 travel miles now, and the underside of the trailer is nearly as clean as when it first hit the road.

I reiterate " the folks in Florida and sunny California may not see the need...........

Snow and ice clings everywhere the wheel sling it and it builds up under and around the wheels . 4 weeks ago the ice was built up in the wheel wells of my car to the point the suspension was all but a mute point. You hit a bump and the tire slams into the ice built up in the wheel wells. Yes it made the ride a bit rough.

When I built the tear I went so far as to lay down a layer of lexan over the bare frame and under the floor for protection.



Rain may fall down but the puddles splash up and the road spray is slung off of the tires hence the need for fenders. In a heavy rain storm up here in the snow belt the underside sees far more snow , ice , slop, and water than you may experience. The flat sealed bottom give it all far fewer places for it to hide.

[aggie79]

What you are planning to do will be plenty strong enough.

Actually 1x2s on edge would be strong enough. Just make sure they span the 6' width of your trailer rather than running lengthwise.

I believe Andrew stated somewhere that "ends" of the trailer do more structurally to support the sidewalls than the floor cantilever.