foamie wall to floor attachment options ?

[rustytoolss]

With in the next few week I should be thinking about attaching my 2" foam walls to my plywood floor base. My plan has been to take 2"x2"s and space them 2" inboard from the outer edge of the plywood. Then glue the foam along the floor surface ,and the vertical surface of the 2x2's.
But I'm open to hear your ideas. Since this is my first Foamie build. I would like to hear from those of you that have built foamies, and know what works the best.
My ttt will be 116"Lx76"Wx72"T. I may use some 2x2's for vertical wall support and roof spars ( as an external frame work skeleton)
I got the idea for the 2x2 wall attachment from a post in the general board index. The post was more about plywood walls. But thought it should work for foam also.

[pchast]

It will work but I question if it is needed If you are planning to glue the foam to the ply and
will wrap your covering under the plywood?

I'd like to hear other's comments.......

[rowerwet]

I just glued the edge of the foam walla to the floor with gorilla glue. Two years and no signs of any loosening.
The fabric sock is wrapped under the floor and this is the only reinforcement I think it needs.
For ease of construction I hammered stainless finish nails up through the floor on the center line of the wall foam every foot or so. This was really only to keep things from sliding around on the glue, but it may also help keep things in place.

[rowerwet]

My tear is a bit larger than a regular one, at 6.6x13 feet

[Don L.]

I think that is an important connecting point and your plan would make it pretty strong. Whether the 2x2 on the inside along the floor helps or hinders the rest of your interior plans I can't say, not knowing your plan and building methods.

[ghcoe]

That is what I did with my build. I added 1"x2" alone the walls and bulkhead as well as the back edge of the hatch. Seemed to work great except for my first glue attempt. I used GS and it pushed the walls up. Before I knew what was happening it was too late. Had to wait for the glue to set up and then cut the walls off and glue again. the next time I did not use as much glue.

Floor

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For my next build I will be using flashing the same way. The flashing will still allow a large wall bonding area but, allow a better wall to floor transition. Then I will add another flashing strip on the exterior along the bottom of the floor and up the outer wall. This will channel the foam and give more glue area. Flashing will be lighter and give nice clean lines to canvas over.

[Don L.]

Another way would be to glue the 2x2 under the bottom of the wall, wrap that with a foot of canvas , some going up each side, then screw the 2x2 to the floor flush with the outside edge. That gives a cleaner inside wall/floor line incase cabinets or boards need to meet up against the wall at the floor. Then your wall canvas can double over that canvas and strengthen the connection. That may not help or it may, I dunno.

[ghcoe]

Another way would be to glue the 2x2 under the bottom of the wall, wrap that with a foot of canvas , some going up each side, then screw the 2x2 to the floor flush with the outside edge. That gives a cleaner inside wall/floor line incase cabinets or boards need to meet up against the wall at the floor. Then your wall canvas can double over that canvas and strengthen the connection. That may not help or it may, I dunno.

The problem I see with that is that the wood and foam have a different expansion/contraction rate. Unless you do not mind seeing a wood/foam joint line telegraphed through the canvas then it will be ok. You will see it though.

[Tempest]

My current thoughts are to screw a 3/4" x 1 1/2" wood key on edge to a plywood base, then notch the bottom edge of the 2" foam wall to go over the wood key. I hope this would provide plenty of gluing surface to hold the wall. Then flash it at the bottom like ghcoe did his foamie and cover with canvas wrapping underneath the plywood floor. I plan on dragging this camper into the backcountry on snow skis so I know for a fact it will get a beating. Just hoping it will TAKE a beating???

[GPW]

“ I hope this would provide plenty of gluing surface to hold the wall. “ JMHO . I don’t that’s going to do a lot .... As we’ve proven over many years now , it’s the outer skin that holds it all together... Gluing foam to wood doesn’t really help much because the foam is still so much weaker than wood ... As tested on Foamie #1 , the foam glued directly to the floor ( GG ) , then skinned inside and out , gave no indication of structural stress, and was Very difficult to remove later ( ask Bonnie ) ...

If you have used a thin plywood as the inside skin well then that’s different ... wood to wood ...

[rustytoolss]

That is what I did with my build. I added 1"x2" alone the walls and bulkhead as well as the back edge of the hatch. Seemed to work great except for my first glue attempt. I used GS and it pushed the walls up. Before I knew what was happening it was too late. Had to wait for the glue to set up and then cut the walls off and glue again. the next time I did not use as much glue.

DSCF2189 small.jpg

For my next build I will be using flashing the same way. The flashing will still allow a large wall bonding area but, allow a better wall to floor transition. Then I will add another flashing strip on the exterior along the bottom of the floor and up the outer wall. This will channel the foam and give more glue area. Flashing will be lighter and give nice clean lines to canvas over.

Your pictures are what I had in mind to do. Make a inner glue point (2x2) around the floor base. And the same 2x2's could also be a point were cabinet structures could be mounted to also.

[lthomas987]

That is what I did with my build. I added 1"x2" alone the walls and bulkhead as well as the back edge of the hatch. Seemed to work great except for my first glue attempt. I used GS and it pushed the walls up. Before I knew what was happening it was too late. Had to wait for the glue to set up and then cut the walls off and glue again. the next time I did not use as much glue.

DSCF2189 small.jpg

For my next build I will be using flashing the same way. The flashing will still allow a large wall bonding area but, allow a better wall to floor transition. Then I will add another flashing strip on the exterior along the bottom of the floor and up the outer wall. This will channel the foam and give more glue area. Flashing will be lighter and give nice clean lines to canvas over.

I remembered your post ( or someone's anyhow) about the glue pushing the walls up and decided to use Gorilla Glue instead. The glue still tried to foam up and push the walls around. I used the curved off cuts of the foam from my front to help square my walls vertically (screwed to the floor and later removed) then a ratchet strap (with rope for length) all the way around the wall on the second one (this required help) but kept my wall mated to the floor during gluing.

I used bias cut linen reinforcing strips and glued them down with TB2 to the foam just like the outer covering but a strip inside and out, about 6" wide before I put my main fabric layer on.

[rustytoolss]

So is walls moving / pushing around a common problem ? I will be using GG also. And if anyone can post pictures of how you supported your walls to keep them vertical (90*)/square. That information would be very helpful

[ghcoe]

So is walls moving / pushing around a common problem ? I will be using GG also. And if anyone can post pictures of how you supported your walls to keep them vertical (90*)/square. That information would be very helpful

I just used the front section that I cut off of the sides, makes a nice right angle.

Support

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GS can have a strong hydraulic lift when it foams up so it can cause problems. It also can set up fast, not giving you much time to get things clamped down before it is too late.

GG sets up a lot slower, giving you time to clamp things down.

I have found GG adhesive in caulk form. So far with my testing it seems to work quite well with foam and steel. Have not tried foam to wood yet, but I am sure it would work good for that too. It is a bit more expensive, but for some applications I think it would be the best solution, such as walls to floor attachments.

GG Caulk

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[rustytoolss]

Your wall support looks simple enough. Thanks