Quazi-ultralight the undertaking

[aggie79]

[quote="RogHodge"]My thought is to use the Box store’s “kiln dried studsâ€

[RogHodge]

Good to be back- although I’ve never been gone- I revert to lurking when I don’t have anything done.

I’d like to get some input about my earlier question. I’ll try to make this coherent:
The floor- the plan is torsion box/hollow core door/ whatever you call that-
Thin as reasonable ply on top and bottom- probably 1/8 – the question concerns the skeleton or ribs- what material and orientation-

Basic ‘furring’ strips are ¾ x 1 1/2, as you know, I could use these and stand them up 1.5â€

[bobhenry]

I would consider the purchase of a #1 grade 2x10 or 2x12 in most areas these are southern yellow pine almost 1/2 again as strong as the spruce / pine / fir lumber you are concidering and while slightly heavier the difference is minimal. Look for a board that does not have the curved grain pattern in the cut end. ( these straighter grained boards were cut form material closer to the heart of the tree and are not as prone to cupping and curling) . #1 is graded to be extremely small knots or knot free avoid #2 and the knots if possible.

[RogHodge]

Around here all 2x material is doug fur- sappy and crappy
I might have to go to a real lumber yard like Frost or Lane Stanton Vance and by some poplar then mill my own stuff

[GreatPumpkin]

[quote="RogHodge"]
I’d like to get some input about my earlier question. I’ll try to make this coherent:
The floor- the plan is torsion box/hollow core door/ whatever you call that-
Thin as reasonable ply on top and bottom- probably 1/8 – the question concerns the skeleton or ribs- what material and orientation-

Basic ‘furring’ strips are ¾ x 1 1/2, as you know, I could use these and stand them up 1.5â€

[RogHodge]

Mr. Pumpkin- I checked out your build- nice looking profile. I think the ¼ is a bit much for the top of the floor- and much too much for the bottom- I will not be standing on this floor other than the occasional misstep during construction- Maybe I should get some “no Stepâ€

[GreatPumpkin]

Thank you, I'm pretty happy with how it turned out too.

- Two 1/4" sheets of 4x8, about 50lbs. Two sheets of 1/8", about 25lbs. Not a lot of difference for most builders. But when you're striving for ultra-light, I guess that is a pretty high percentage!
- You're certainly right about the bottom, you should be able to get by with 1/8" there without any issues.
- I'd be too worried about the top layer to go with 1/8". I know that I would invariably put a knee or foot thru it during the construction phase. But beyond that, it would probably be plenty strong also. It works for interior doors! Maybe put down another sheet of 1/2" or whatever, just laid in place thru the build process to protect it.
- I was referring to the finish of the floor, but again it's covered by the mattress, so it won't be seen. (My hardwood ended up costing me less than the alternatives, so it worked out great even thought it will be covered)
- Top of trailer - are you considering aluminum skin over 1/8" ply, or just directly onto the spars? Insulating?

[aggie79]

Rog -

It's time for some updates. How are things going?

[RogHodge]

Tom,
You are so right- I need to get to work. The update is that I’m still alive, I’ve taken up running, money is still tight, and I’ve done nothing on the trailer.
I have been building huge redwood pergolas/patio covers in my mother-in-laws place. Thank you for the encouragement. Your build is looking good by the way.

[dwgriff1]

You asked about the webbing inside the "torsion box".

Mostly that grid is to keep the two skins properly spaced. That hollow core door may well have an egg-crate looking thing inside.

I used a lot of oak because I had it and it does not take all that much. In the end my decision to thickness was determined by the thickness of the foam insulation.

That insulation is never what they say it is!

BTW, my pan is 1" thick with 1/8 on the bottom and double 1/8 on the top. One could get away with less on top, but I probably would not. When you move around the inside without the mattress that extra feels stronger!

Keep in mind that that thin skin will puncture quite easily so inspect it often. Luckily it is easy to repair.

Since you have a frame any affordable fairly light wood would work well.

dave

[RogHodge]

I’m still alive for those who are counting. I constructed three- count them three, pergolas- like a patio cover- I will add a photo some day. Completely ate my weekends for months. But added a few bucks to the trailer fund

I bought a tongue jack from HF and will install that soon. I have decided to add a receiver to the rear of the tear- mainly for a bike rack. Unless someone wants to talk me out of it- I know this will affect tongue weight but I will put in a tongue box and install the battery up front. There you have it- all the news that isn’t.

I miss our little chats…

[RogHodge]

On last question about the torsion box (yea right)

When creating the webbing inside the box I will need to create a span that overlaps the frame. Some of the spacers inside the box will be able to run full length and others will be short ‘filler strips’ if that makes sense- so… should the long pieces run sideways or front to back. I’m considering a half-lap joint at the intersections which may be the best of both worlds. The other option is that I’m seriously over thinking this and I just need to get going.

For what it’s worth I’m settling in on 1/8 bottom- ¾ ‘furring strips- double 1/8 top (double the 1/8 rather than 1/4 to get more plys from cheap wood probably glue the sheets together in place)

[john]

torsion box?

[RogHodge]

Torsion box-

My floor shall be a torsion box- sits on the frame- where I shall sleep- the walls will be fasened to.

Throw me a bone guys -

[bve]

On last question about the torsion box (yea right)

When creating the webbing inside the box I will need to create a span that overlaps the frame. Some of the spacers inside the box will be able to run full length and others will be short ‘filler strips’ if that makes sense- so… should the long pieces run sideways or front to back. I’m considering a half-lap joint at the intersections which may be the best of both worlds. The other option is that I’m seriously over thinking this and I just need to get going.

For what it’s worth I’m settling in on 1/8 bottom- ¾ ‘furring strips- double 1/8 top (double the 1/8 rather than 1/4 to get more plys from cheap wood probably glue the sheets together in place)

Rog good to see you back... I want to see those pergola pictures.

For the 'span' you refer to, it looks like will it overlap on the back? My frame is narrower than the floor is wide, so I will be running the floor framing full width side to side and 'filling in' front to back. I don't think it will matter - either way the floor is part of the larger box, and will gain strength when the walls and roof are attached. On your's with the overhang at the back I would run full length front to back, and fill in side to side.

The other option is that I’m seriously over thinking this and I just need to get going.

Nothing wrong with that, it's better than under thinking it.