Don't do it.


It takes a wise person to ask for advice. It takes a wiser person to take that advice.


Once the floor is down with bolts and some cabinets on top, it will not squeak. Do not spend your effort on gluing it down.


Put some reinforcement under the plywood right around the bolt holes so that the plywood is not compressing only against the XPS. Bolts need some tension to hold and the XPS will compress too much. I used PVC pipe cut in I inch lengths as collars, but you could use plywood.


If you know that you will not be able to get to those B pillar covers, I would take those screws out. However, with 1 inch XPS and 3/4 inch ply I don't think I blocked anything, so check your math.

 

Thanks Thom. Did you glue between the plywood and the XPS? I'm using 1/2" ply not 3/4. I like the idea of sleeves for the bolts and had been thinking about this issue. I'll check again on the B pillar screws. Still hard to believe the squeaking goes away without adhesive but I love the idea of not having to glue it down. One of my issues is the I will be camping in the van throughout the build so if I'm relying on the cabinets for weight it could be a while before they are done and I'd go crazy as Squeaky McSqueakiy until then.

 

Thom is correct - don’t glue it down.

 

No glue.

After my floor went it I went a while with no cabinets. No squeaking.

Even if you get some combination of setup that does give you a squeaky floor, it won't be hard to pull the floor and do something about it. That's very unlikely, but is a good reason to skip it for now. If you are not sure you need something and it is easy to retro fit, leave it for later.

 

I'm going to give the no glue a shot. I have trouble with commitment and this is very attractive to me.

Thanks guys.

 

3/4” Plywood on XPS High Load



Hi Dylan

I used high load XPS 1” on the van floor no glue then 3/4” marine type grade baltic birch (5’ x 10’ & 4’ x 8’ for no visible joints). I stained & clear finished the top of the plywood & bolt using a countersink thru to the underside of the metal van floor 8mm bolts. Had a little squeaking due to my rigid insulation being too tight against the step of the cab. I fixed that & don't have squeaks now

I would not use glue or any adhesive. Thru bolting did the trick for no squeaks (ensure the rigid insulation is not too tight against a vertical surface)

 

additional bolts?

For those that do not use adhesive and only bolts. Did you only use the factory 8mm tie down locations or add some of your own? Would self taping screws work? I've go the 1" XPS and 1/2 " ply down with only the factory 8mm and it is squeaking(no cabinets on top yet) when walking on it. It is not touching the sides of the van. As recommended above I did add plywood shims at the bolt locations as to not compress the XPS and give the bolts something to tighten against.

 

No Existing Tie Downs Used

For those that do not use adhesive and only bolts. Did you only use the factory 8mm tie down locations or add some of your own? Would self taping screws work? I've go the 1" XPS and 1/2 " ply down with only the factory 8mm and it is squeaking(no cabinets on top yet) when walking on it. It is not touching the sides of the van. As recommended above I did add plywood shims at the bolt locations as to not compress the XPS and give the bolts something to tighten against.

Hi Dylan;

I did NOT use the factory tie down locations. I used countersunk heads 8mm 3/4” plywood side & a washer/nut on the underside of the van floor (then zinc rich spray coating to prevent rust)

I drilled up from under the van, thru the metal van floor, thru the xps 1”, thru the 3/4” plywood; then installed a countersunk hex (Allen Key) from the top side (plywood) & a washer/nut on the underside of the van. When drilling up I only drilled thru (high pan flutes) of the van floor

 

My floor has 3 sections, none of the sections are tight to the walls or each other.

I'm guessing where you have the XPS butted up to the next section(s) is rubbing.

Where is it squeaking?

 

Make the plywood shims a little thinner. You do want to compress the XPS just a little.

 

Make sure it's not the ply squeaking but if it is just think of it as a vintage van with old wood flooring. If the foam is squeaking alum foil tape will stop the squeak.

 

... not to hijack this flooring thread, (it's just so relevant here) ... but how do folks determine the tie down positions for drilling hole in the plywood floor when the tie-down nuts are not visible under the van to drill up through (except for the slider position)?

 

... how do folks determine the tie down positions for drilling hole in the plywood floor when the tie-down nuts are not visible under the van to drill up through (except for the slider position)?

Can't remember exactly, but I probably put reference marks on the walls 90deg to each hole and took offset measurements from them. Then put the plywood down and transferred the measurements.

 

I removed the tie downs and put an 8mm hex head bolt all the way down in the hole. Then put the plywood on top and (gently) jumped up and down on that spot. Makes a nice imprint of the hex head on the plywood. If you careful to center the drill, you can get a nice tight tolerance hole.

 

Roughly how many of these would you say you used or what spacing did you use?


Thanks

 

Roughly what was the spacing on the thru bolts?


Thanks

 

Rough count thru bolts



IIRC; 4 rows from front to back @ 8 = 32 thru bolts