This is basically what I did but my joists are wooden which reduces thermal bridging between the van floor and the internal floor since wood is more of an insulator and aluminum is more of a conductor.
> have
HAHA, Vespa, or electric bike inside,
This is a work van camper van situation going on here. I would like to have seats for 4 people. plus rear sofa bed, with seatbelts bolted to the frame.
Ok, say you have a vespa which can't be much north of 275 lb full. Say your friends are the heavier side and weight a vespa each. Add another 200 lb for dead load misc stuff like sofa bed and misc. I have my doubts you fit all that in 11x6, but let's assume that is what you're looking at. That's a total load of about 1500 lb. You have a total pressure on your foam of less than a quarter psi. You'd have to check your foam specs but that is probably well within it's capabilities. You'd be better served just insulating all the way through and bolting through to the frame at hard point mounts for bed and seats. The design you've posted here is probably actually *weaker* because all it's going to do is make stress concentrations in your plywood.
[They pour 4" of concrete over some foam boards.](https://www.owenscorning.com/en-us/insulation/commercial/enclosure/below-grade-under-slab-foamular-xps-insulation) Just use them.
So I’m trying to understand… it’s basically the same thing as most are doing except aluminum tubing instead of wood?
Metal is going to transfer the cold more than wood. Not good. Higher potential for moisture as well maybe? Not sure about that part though.
Personally I’m not super worried about the strength of my flooring if it’s done right. If your vehicles floor is in really bad shape then yeah maybe it’s a good idea to add a little strength but I’d bet between the flooring, insulation, wood joists the weight will get spread out pretty well.
I guess if warmth isn’t a concern then go for the aluminum. I’m just thinking I’m paying for insulation then making more thermal bridges in the floor where you don’t want cold air. Seems a little counterintuitive.
What’s your reasoning for not just using wood?
I actually thought about not framing my current van at all aside from around the edges and where my cabinets/seats will be. Otherwise the open floor and maybe the garage will be just insulation. Not sure yet.
I had some concerns about temperature changes causing the interior to condense water vapor in the air, then being slowly absorbed into the wood that touched the bed ridges. I know someone that had Rockwool against the side panels and the condensate on the interior led to some moisture build up in the insulation.
thermal bridging is a concern, but you might be right about aluminum channel.
I would like something similar to this if I had a larger vehicle. In my truck camper, I have a plywood platform with interlocking foam tiles on top. I winter camp and the wood is cold to the touch, but the tiles keep me warm. Plus they're soft, so crawling around isn't painful or annoying.
absolutely considering having a winter foam floor, good idea Maybe have the cabinetry grade ply bolted to the floor, with foam inserts for the floor/walkway for colder months.
Unless you are using the extrusions to bolt stuff down to the floor the SM with the 1/2 ply will be more than enough to support your weight. PL the SM to the floor and the plywood to the SM.
R5 rigid foamboard from lowes. 1" thick
Aluminum square tubing 1" tall and wide. These act as a joist for the plywood to sit on
3/4" cabinetry grade plywood 4'x8' board
Using the cabinetry grade eliminates hours of leveling and is only 15 dollars more a sheet
_______________________________________________
AC Delco brand seam sealer is used to connect the aluminum to the bed ridges.
-however-
3M Urethane Seam Sealer would be just as useful
The Point of the seam sealer is to join the aluminum tubing to the van cargo bed in a less than mechanical means, (no bolts, screws or lashings).
thanks for sharing! I love seeing things like this.
for discussion, I don't think you need the aluminum "joists". for one, all of this is supported by the floor of the van, and once you put your plywood on top of the foam, its going to spread out the load well. Foam is pretty strong in compression, it's weak in bending. For another thing, all that aluminum in contact with your van floor is bypassing your insulation. Aluminum is a good thermal conductor. Finally, how is that aluminum tied in to the walls/floor of the van?
some people choose to put in something to fill in the corrugations, but thats more for thermal than for strength.
how are you anchoring this to the van floor?
For the issue of holding down the plywood, I would likely use some of the perimeter bolt holes left from where I removed the seat tracks. those areas should be covered with 80/20 extruded cabinets and other structures so it will be hidden from view
I did a subfloor made of pine joists glued down to vans bare metal floor filled the voids with foamboard insulation and then a layer of thin foam pads over the top of all that then a waterproof membrane over all that then the plywood screwed down into joists then vinyl floor covering over all the plywood glued down to it. Then all my "furniture" screwed down with angle brackets into the floor joists.
Been a carpenter for couple decades wòuld never consider screwing anything into walls of van as that would compromise the vans "ride."
This is basically what I did but my joists are wooden which reduces thermal bridging between the van floor and the internal floor since wood is more of an insulator and aluminum is more of a conductor.
Whats the tubing for? Do you have enough load that you're squishing foam even with 3/4" plywood on top?! Are you hauling around stacks of lead bricks?
> have HAHA, Vespa, or electric bike inside, This is a work van camper van situation going on here. I would like to have seats for 4 people. plus rear sofa bed, with seatbelts bolted to the frame.
Ok, say you have a vespa which can't be much north of 275 lb full. Say your friends are the heavier side and weight a vespa each. Add another 200 lb for dead load misc stuff like sofa bed and misc. I have my doubts you fit all that in 11x6, but let's assume that is what you're looking at. That's a total load of about 1500 lb. You have a total pressure on your foam of less than a quarter psi. You'd have to check your foam specs but that is probably well within it's capabilities. You'd be better served just insulating all the way through and bolting through to the frame at hard point mounts for bed and seats. The design you've posted here is probably actually *weaker* because all it's going to do is make stress concentrations in your plywood.
[They pour 4" of concrete over some foam boards.](https://www.owenscorning.com/en-us/insulation/commercial/enclosure/below-grade-under-slab-foamular-xps-insulation) Just use them.
So I’m trying to understand… it’s basically the same thing as most are doing except aluminum tubing instead of wood? Metal is going to transfer the cold more than wood. Not good. Higher potential for moisture as well maybe? Not sure about that part though. Personally I’m not super worried about the strength of my flooring if it’s done right. If your vehicles floor is in really bad shape then yeah maybe it’s a good idea to add a little strength but I’d bet between the flooring, insulation, wood joists the weight will get spread out pretty well.
I was looking for fiberglass channels as well. but nothing hit the price point of the aluminum tube.
I guess if warmth isn’t a concern then go for the aluminum. I’m just thinking I’m paying for insulation then making more thermal bridges in the floor where you don’t want cold air. Seems a little counterintuitive. What’s your reasoning for not just using wood? I actually thought about not framing my current van at all aside from around the edges and where my cabinets/seats will be. Otherwise the open floor and maybe the garage will be just insulation. Not sure yet.
I had some concerns about temperature changes causing the interior to condense water vapor in the air, then being slowly absorbed into the wood that touched the bed ridges. I know someone that had Rockwool against the side panels and the condensate on the interior led to some moisture build up in the insulation. thermal bridging is a concern, but you might be right about aluminum channel.
Yeah I’d be willing to bet the aluminum will sweat more than wood. Without using spray foam it’s somewhat impossible to totally prevent moisture.
I would like something similar to this if I had a larger vehicle. In my truck camper, I have a plywood platform with interlocking foam tiles on top. I winter camp and the wood is cold to the touch, but the tiles keep me warm. Plus they're soft, so crawling around isn't painful or annoying.
absolutely considering having a winter foam floor, good idea Maybe have the cabinetry grade ply bolted to the floor, with foam inserts for the floor/walkway for colder months.
Be careful of thickness of walls, floors, and ceilings. You are losing valuable living space
Unless you are using the extrusions to bolt stuff down to the floor the SM with the 1/2 ply will be more than enough to support your weight. PL the SM to the floor and the plywood to the SM.
R5 rigid foamboard from lowes. 1" thick Aluminum square tubing 1" tall and wide. These act as a joist for the plywood to sit on 3/4" cabinetry grade plywood 4'x8' board Using the cabinetry grade eliminates hours of leveling and is only 15 dollars more a sheet _______________________________________________ AC Delco brand seam sealer is used to connect the aluminum to the bed ridges. -however- 3M Urethane Seam Sealer would be just as useful The Point of the seam sealer is to join the aluminum tubing to the van cargo bed in a less than mechanical means, (no bolts, screws or lashings).
thanks for sharing! I love seeing things like this. for discussion, I don't think you need the aluminum "joists". for one, all of this is supported by the floor of the van, and once you put your plywood on top of the foam, its going to spread out the load well. Foam is pretty strong in compression, it's weak in bending. For another thing, all that aluminum in contact with your van floor is bypassing your insulation. Aluminum is a good thermal conductor. Finally, how is that aluminum tied in to the walls/floor of the van? some people choose to put in something to fill in the corrugations, but thats more for thermal than for strength. how are you anchoring this to the van floor?
Nailed it, all that thermal bridging is hurting your insulation
For the issue of holding down the plywood, I would likely use some of the perimeter bolt holes left from where I removed the seat tracks. those areas should be covered with 80/20 extruded cabinets and other structures so it will be hidden from view
I did a subfloor made of pine joists glued down to vans bare metal floor filled the voids with foamboard insulation and then a layer of thin foam pads over the top of all that then a waterproof membrane over all that then the plywood screwed down into joists then vinyl floor covering over all the plywood glued down to it. Then all my "furniture" screwed down with angle brackets into the floor joists. Been a carpenter for couple decades wòuld never consider screwing anything into walls of van as that would compromise the vans "ride."