Expand/Contract: Glue & screw 7" x 3/4" OSB strips on top of 3/4 plywood subfloor ?

iMisspell · 12-08-2008, 12:32 AM

Im gonna be cutting up some 3/4 OSB to make strips for "on top" radiant 1/2 pex heat.
This will be on top of a 3/4 t&g plywood which sits on 11-7/8 tgi joist (which i did not glue

).
Im thinking to glue and screw the strips so no squeak develops over time, a friend advised against because by gluing will leave no room for expansion and contraction and over time with the pex heat in the floor it will start to buckle.

Your opinions ?

Heres what i planed on doing.
Cutting up some 3/4 OSB (already have) in 7" strips at around a 15 deg angle the length of the cut.
Using 1/2 pex (3/4 O.D.) will space the strips 3/4 from one another and create a dove tail so the pex will "snap" into place (trying to mimmik what ive seen in the past with "over the top" panels) and glue and screw down the strips.
With a jig saw, create the radius for looping back.
Then placing oak hardwood on top.

So the main question is, will screwing & gluing these strips and the use of heated pex between them cause problems with the floor down the line ?

Thanks for any opinions.

_

Marvin Gardens · 12-12-2008, 10:40 PM

It's hard to say what will happen. It is not the orthodox way to do it and when people mention glue and screw there is no backing up. It is pretty much permanent.

iMisspell · 12-13-2008, 12:10 PM

Thanks.
i think im just gonna screw it for most of the floor and then for the bathroom section i will glue and screw being tile will be installed.

Marvin Gardens · 12-13-2008, 01:34 PM

Quote:

Originally Posted by iMisspell

Thanks.
i think im just gonna screw it for most of the floor and then for the bathroom section i will glue and screw being tile will be installed.

It might work but I can't say for sure. I hesitate to take a stand either way. This is why I didn't respond to your post at first because I waited to see if others would respond.

At the very least I would get the plastic supports for bending the pex at the ends of the floor. These have screw holes to secure the pex to the floor. It has a tendency to twist when heated if not secured. I always make sure that I stretch out the pex before I install it to get as much of the twist out of it I can.

angus242 · 01-09-2009, 02:41 AM

I caught up with this thread via the other one you replied in. They were talking about radiant UNDER the floor there. Here you're talking about radiant OVER the floor.
I can tell you I've been searching for radiant panels that I could use over the floor for various differnt finish materials to be installed on top....radiant for the whole house. I started with Infloorboard.

Unfortunately, they won't work as my project begins with a finished tile floor. I went round and round with the Infloorboards. Basically, the TCNA advised against install tile over them. I was left with no other known options. I, too, was going to just make my own. I was going to use 3/4" ply and route out my own channels, install aluminum plates and then use 3/8" pex.

That would have been a HUGE project. However, I have just come across what I believe to be my answer. I really didn't want to raise the floor height that much anyway. I just found a 1/2" panel made for pex. Uponor Quik Trak:
http://www.uponor-usa.com/Header/Ser...tallation.aspx

Uponor installed (pic too big to post):
http://i264.photobucket.com/albums/i...1/100_0690.jpg

I need to get the OK for my project and then order them. I can post back with my results if you'd like (and if I actually contract this job)

iMisspell · 01-09-2009, 03:17 AM

Thanks, Angus.

Ive looked at this (someone posted a link to it some where (i think it was that BuilderBob person)) and for myself it will cost more then i would like to spend, but i would love to hear how you make out.

I think those panels have the alumone strips mended on the bottom of the panels (to create more of a mass heat ?? ).

If i remember; it would have been around $2,300 for the panels, i got the OSB for around $300 and paid $300 for aluminum strips (600 total), so for me it was a financial decision (and i have no time limit being its for myself).

But yes- if you remember, i would like to hear how you make out.

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angus242 · 02-19-2009, 12:29 AM

My bathroom project finally started. I finished laying the radiant subfloor today. Here's a shot of it.
Overall, I thought it was pretty simple. However, there's a part of me that says it should be easy to do this yourself with some aluminum strips and a router. I'm not sure how easy it would be to router out 100's of feet for the pex channel AND make them straight.
I was impressed with the Uponor boards. Aluminum attached beneath was fairly thick. WAAAAAAAAAAYYYYYYYY better than the original Infloorboard that I had. Those were TERRIBLE! MDF lined with a sticky aluminum foil that didn't even line the pex channels. I just don't see the point of manufacturing a subfloor product out of MDF. If I were to make one myself, I'd use 5/8" ply and route out the channels.
How's your project?

iMisspell · 05-11-2009, 04:40 PM

Thanks for posting back angus242 (and sorry for the late response).

Have not done too much with this yet (took a "winter break"), hope to start this part of the project in the next month or so.
A few months back i did rip some 3/4 into strips at a 15-20 degree angle and plan on making a little "jig-form-stamp" to bend the aluminum sheets i have (like in your picture two posts above).

Once i make some head room with this i'll post some pics when the process starts to take form.

Thanks again for sharing.

_

**Gary in WA** · 05-11-2009, 08:09 PM

Might want to check the ingredients of oriented strand board, they used to make it with formaldehyde in the glue, I think. I know, I wouldn't use it next to a heat source. Course it wouldn't get hot enough to burn, but stink. Warm some up in your oven set at heating temperature. Be safe, G