Flooring T & G or not?

[Jim Eh.]

Time to replace the floor in my build. I have a concern about using straight cut plywood that just butts up to each other. Tongue and groove plywood adds almost another 60% - 70% to the cost of a sheet of 3/4" (if I can even find it - so far only 5/8"). My thought is to use G1S and using a router form a shiplap joint on all mating surfaces. I could go out and buy router bits to form my own T&G joints but will I ever need/use them again - probably not.

Other options?

[TomC]

Use whatever system that is originally in place-it's worked well this long. I would think T&G could create either creaking or board warping without the butted crack. On my cabinets, all joints are mechanically joined by brackets only to allow for flex. Gluing sounds good on paper, but then can cause wood cracking. With bracket only construction, I can take any part of the bus apart if needed. Good Luck, TomC

[eagle19952]

I can take any part of the bus apart if needed.

i can too.
you never know when this will be appreciated.
i would simply overlay the original floor if it is weak just to have a solid floor.
3/4 inch.

[brmax]

Man! I didn't realize that much, not there yet ( big listening here though). I agree if no other outlet can be found cheaper. I have plenty of bits "some where" and will start looking,  dang I had umbrella drinks in mind for the afternoon.

Good Day

[luvrbus]

The Prevost has the best design in sub flooring IMO they use use two layers of 1/2 in plywood with a 1/8 in insulation between the two sheets glued and screwed the Prevost is sure quite with a strong floor but a bitch to remove 

[skihor]

The Prevost has the best design in sub flooring IMO they use use two layers of 1/2 in plywood with a 1/8 in insulation between the two sheets glued and screwed the Prevost is sure quite with a strong floor but a bitch to remove 

Although I've never "re-floored" a bus that sounds like a great way. Being a carpenter I would suggest that the seams be "offset" in both directions. The floor then becomes a solid 1" thick floor. It would probably be strong enough that you could even lay tile directly on the wood floor, although I would recomend 1/4" backer board or "ditra", (the orange sheet stuff) available @ Home Depot.
Don & Sheila

[Jim Eh.]

The Prevost has the best design in sub flooring IMO they use use two layers of 1/2 in plywood with a 1/8 in insulation between the two sheets glued and screwed the Prevost is sure quite with a strong floor but a bitch to remove 

This sounds like a very strong option albeit a little more $$$ than a single 3/4" but you are getting more.

Yes, offsetting in both directions would be a positive thing. I would think if you were to allow any kind of movement would it be best to allow it at the edges, kinda like a slab floor? If that is even possible of feasible.

I am not sure overlaying the original floor with that alum seat rail is possible. I suppose I could router out a channel in the plywood.

As far as a bitch to remove, ah, would I ever really want to? I think at that point a match would work very well. 

So the consensus is to NOT use T&G?

Great input guys, thank you.

[brmax]

I am not sure what its running in the great north but here in the Midwest its showing
35. for bcx standard edge
25. for cdx "            "
32. for t&g sturdi floor that looks every bit bdx or better and all exterior glue they say.
This was on Menards site and 3/4" material, I think they are having an 11% deal going.
I'm sure Lowes down the street is close in price also.
I was looking at pics but haven't a clue as yet the distance between or useable mounting so welcome your findings. thanks

On the subject which I am glad was brought up insulating in, around, under, between.
I would like to hear anymore experiences you all have to contribute in that area if I might without cutting in here (don't mean to) where is it that most use in insulating, the main floor or bay floors , just curious.
Thanks and Good Day to ya

[akroyaleagle]

I would use the "red" paper available at the box stores between the layers.

It is designed to prevent squeaky floors.

I'm not familiar with MCIs, but Eagles have access panels to the tunnel that might have to be gotten into later.
If you don't plan for that, you might have to destroy the floor to gain access.

Any of the discussed ways will work. If you're laying any tile, I would lay it on backerboard.

[Jeremy]

My floor has a layer of plastic-skinned squashable foam on the underneath as insulation - I forget what the material is called but I've seen the same stuff sold by acoustic insulation suppliers. It's a simple but neat system because the foam is obviously applied to the entire surface of the plywood floor before it is placed into position and fastened down, and it simply squashes down where the plywood touches the steel supporting beams and thus becoming a useful gasket between the two surfaces.

My floor panels are butt-jointed together but the floor also has various aluminium-framed access panels in it where there are items underneath that need to be accessed from above. There's no question in my mind that a 'one piece' floor made using the method described as being used by Prevost, (or glued tongue-and-groove) is the ultimate approach - I don't really buy the argument that butt-joints are better because you might sometime want to remove a panel - especially given how much hassle it would be to merely access an entire floor panel once your conversion is complete. And, for the sake of saying it, I also definitely don't subscribe to the concept of not using glue anywhere in the bus interior on the basis that every joint needs to be able to flex.

Jeremy

[sparkplug188]

I used Advantech 23/32" tongue and groove glued down to the steel frame with Sikaflex 221 AND screwed every 3 inches with 1-1/2" deck screws. Press fit pieces of fireproof mineral wool insulation 2" thick were cut and fit before laying the subfloor. Contact cement and 2-3/8" deck screws with fender washers holds the mineral wool insulation in place.

The first person that walked on the new subfloor commented "It sounds and feels like I am walking on concrete.  Every other RV I have been in feels shaky and sounds hollow. This is totally unexpected."

My floor is the definition of overkill and permanent. It is not intended to be removed.  The full length of the tunnel is accessible from the underside.

[Jim Eh.]

Hey Sparky,
I assume the insulation is attached to the underside? Is there any protective barrier or is it not exposed to the basement on that model?

[sparkplug188]

Krank-  I plan to cover the exposed insulation with a layer of painted 1/4" utility ply with rows of 4.5" recessed led lights.  The wheel wells will be lined with corrugated plastic sheathing to protect the insulation from rocks and debris, not water.

Check out this video on mineral wool-- specifically 4:10 http://youtu.be/gLDxhbKfVeo