Replies

1. 
   Ragnar17 | Nov 06, 2006 01:23am | #1

   I'm not a flooring expert, but I think there's a real advantage to using a tongue and groove panel product for subflooring.  If you can find that type of product in a 1/2" thickness, I think it would be fine given the fact that you're putting it on top of a subfloor already.

1. 
   Piffin | Nov 06, 2006 02:39am | #3

   He already has a subfloor, this is anunderlayment ply he is putting down. I usually get it in half inch pine AC for something like this, naail and glue it down with ring nails at8"oc field and 6" edges. All those nails and glue make T&G unnessesary. Also, the underlay ply I get omes with a waxed edge whih prevents sqeeks sheet to sheet and helps prevent swelling from moisture. 

    

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1. 
   Ragnar17 | Nov 06, 2006 09:37am | #5

   He already has a subfloor, this is anunderlayment ply he is putting down.

   OK, you're right.  We're talking about underlayment here.

   All those nails and glue make T&G unnessesary. Also, the underlay ply I get omes with a waxed edge whih prevents sqeeks sheet to sheet...

   This part seems contradictory, Piffin.  If all those nails and glue are doing their job, (i.e. stopping relative motion between adjacent sheets of _underlayment_), why would it be necessary to take precautions to stop squeaks?

   I might be wrong, but my concern is that whenever you encounter relative motion between adjacent floorboards, you have a potential for cracks to develop in your finish floor.   That's why I like the T&G.

   Edited 11/6/2006 1:52 am ET by Ragnar17

1. 
   Piffin | Nov 06, 2006 01:32pm | #6

   Naturally, T&G is better, that is right. But I don't think it is available in 1/2" and the other thing is installation - It is easy to sheath an entire floor on framing before walls are up with T&G, but in a smallish chopped up kitchen when notching around things, T&G is difficult at best to fit together and there are places where it is impossible and the T&G edge has to be cut off anyway. 

    

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1. 
   dieselpig | Nov 07, 2006 01:12am | #10

   Spoken like a man who has "been there before".  I agree.... 1/2" AC pine is the perfect choice in this application.  I'd agree with the other guy too......it's worth the time to make sure all the existing planking is properly secured before starting the new layer.  And as always...... lotsa subfloor adhesive.View Image

2. 
   Shep | Nov 06, 2006 01:42am | #2

   are you taking about yellow pine ply, or white pine?

   either way, I'd use fir AC or PTS ply under the vinyl. Both have a smooth face which won't telegraph thru the vinyl.

   3/4" is fine, but 1/2" would be plenty too. Are you trying to match floor heights in other rooms with the 3/4"?

   I'd also suggest screwing down the 1x8 boards before putting down the ply. Since everything is open and exposed, you might as well take the time to minimize any floor squeaks.

1. 
   rick12 | Nov 06, 2006 06:40am | #4

    

   Shep, is it white or yellow pine ply at the So. Plfd big box store? It looked like yellow to me. Will people pay more for fir ply because it is more moisture resistant than pine ply??  And what does PTS stand for? Something sanded?

   Good suggestion about screwing down the 1x8 boards. There was a lot of squeaking and thats one reason I removed two old layers of ply to get at the subfloor. Most all the  boards are slightly cupped up although they each had 2 nails at each joist.  I already hammered the nails down and most of the squeeks are gone. But now I wish i would have removed the raised nails and inserted screws in the holes. There's still time to add some screws. Thanks for your help.

   What do you all think of cement coated coolers compared to ring shank nails?

1. 
   Piffin | Nov 06, 2006 01:34pm | #7

   Fir ply is slighly stronger and lies flatter than pine, but pine often has a smoother surface - less likely to telegraph grain pattern through a thin vinyl floorcovering 

    

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1. 
   dryhter | Nov 06, 2006 04:18pm | #8

   Hey Piffin,

   Here in northern Ohio:

   FIR usually is available in 3/4-1/4, AB and /or BC plugged and sanded,But the core layers have voids, so the veneer layer can punch thru if used as a underlayment. Bummer!

   Ply specifically for underlayment is usually Pine (SYP), 3/4 ,5/8, 1/2in., all have filled core veneers to prevent blow outs, and only the 3/4 is available in T&G.

   It's amazing how different things are across the country.

1. 
   Piffin | Nov 07, 2006 02:01am | #11

   That pretty much agrees with my experience and observations. 

    

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2. 
   Shep | Nov 07, 2006 12:29am | #9

   I really have no idea what the So Plfd HD has, but I'd guess yellow pine.

   I deal with Huston Lumber in Watchung. They have everything HD has and more, along with sales people who know what they're talking about.

   PTS means Plugged, and Touch Sanded. It's basically an underlayment plywood thats a grade below AC ply. It's what I use most of the time over the subfloor.

   Ring shanks probably hold a bit better than CC coolers, but not difference enough to really worry about.