Floor Question?

[heathnlaura]

So my better half and I decided to put down 1" R tec foam with sheeting on both sides, 1/2" 5 layer plywood secured with 2 3/4" Teks screws, and 1/8" floating floor on top. When I say we decided to, I mean we've done everything but the floating floor so far. We didn't do any framing underneath the plywood. We figured with the plywood and floating floor it would displace enough of our weight so as not to crush the foam.

But before we get too far long we were wondering if anyone else has done their floor this way, without the framing that is. If so, have you noticed any sagging at all? How long did it take to start sagging? I understand framing can add the strength to the floor, but I was wondering if it was just one more thing to do that wasn't really necessary but was done "just to be sure".

Any advice would be much appreciated.

Thanks

[JakeC]

That is almost exactly what I did. Worked awesome and I don't feel anything move. I just quoted the whole post so you can read my description. In the last pic, the 2x2's you see along the edge are on top of the plywood, not the flooring.

Originally Posted by JakeC

Here are some pics of where I am at so far. I have my insulation (3/4") installed and my plywood subfloor. I did use rosin paper under the foam. I tried to keep the plywood as "floating" as possible. I know it needs to be secure, but I don't want more holes in the floor than I need. My solution was to put down 3.5"x3.5" pine squares in the center of every seam, and where ever else I deemed necessary. I did not put any along the sides. Instead, I will have 2x2's running along the perimeter holding the plywood down tight around the edges. Doing it this way, it is secure, allows for expansion/contraction, minimized the number of holes in the floor, and will be fairly simple to remove if I ever need to. I did use liquid nails as well as screws on the blocks. I did have to go through it and put a few extra screws in to make sure my seams were flush. I am very happy with it so far...! One reason I can get away with doing it this way is that I am installing a floating laminate floor from front to back with a nice pad/underlayment that takes up fairly large imperfections. Anyway, here are the pics. More should be posted tomorrow as I hope to get the flooring installed. I'll get a pic of the front, too. I was able to get it all in one piece, not sections.

[Accordion]

This is 3/4 inch stiff styrofoam board that I got at Home Depot. I just cut it to fit tight from one wall to the other.

Notice that the walls were also insulated with the same stuff. I spray glued the stuff on the wall, but just placed the floor insulation without gluing it.




And another piece goes down.




Now, around the dog bed and up to the front. We also drew a center line in order to lay out the flooring boards. Beyond the front line, we used plywood and carpeted it so it would end up the same height of the finished hardwood floor.





3/4 inch tongue and groove flooring boards were used. The insulation underneath has not compressed.

10 boxes of the flooring was enough to do the floor in the front room and the bedroom, as well as the side walls in the front room.

Here, we are installing the center strip in the front room. We are working towards the rear.

How we installed it was: I laid a thick bead of silicone on the bottom of each board. I ran a stripe down the middle. Then we just simply put them into place.

[heathnlaura]

Thanks for the reply guys. Both floors look great. I hope ours comes out looking as good. With the few posts I've seen with pics that had framing, what I was looking for was at least one person who did it like we did with no trouble, so I'm happy.

The big difference is the both of you have the pink insulation and we have the white 4x8 sheets of Insulfoam. It's expanded polystyrene. Is that any more or less rigid than extruded polystyrene?

[opus]

I did the floating floor: https://lh5.googleusercontent.com/-N42f ... 001924.jpg

I put a 2 x 2 between the sheets I think to help support he plywood. No sagging. I do have a squeak over the fuel tank repair hole in the middle of the floor. Nothing drastic.

[ThePimentals]

Wouldn't 1/5" be a little thin for no supports. If you did 3/4" I would think that would be ok

[heathnlaura]

I think you're referring to the plywood thickness. It's actually 1/2" and it's 5 layer. If you look at the layers of the plywood from the side, you can actually count them. The more layers, the better, or stronger anyway. It's also typically more expensive by a bit, which may not make it better in some peoples books.

[ThePimentals]

I meant 1/2 not 1/5. But 1/2 inch is pretty flexible. I was thinking it wasn't enough support. But let me know because its way less money than 3/4.