Now in all my years I havent actually run into this so I am looking for advise.


Customer has 2 1/4x3/4 installed over vinyl and underlayment (those 3x3 panels) the ones that get a million staples to put them down. I will be weaving into the flooring to add another room, I know I will have to build the floor up. I dont want to put the same underlayment down, I plan on using 3/8 or 1/4 cdx. I have never put any substate down that was less then 1/2 inch wich I glued and screwed down. It seems to me that glueing and screwing the 1/4 or less that the screws wont hold the same as stapleing it down, or will go right through it.

So my question is, what size & guage staples to use, and how often to staple?







***I have run into plenty of cases where I have taken the V&U out to put a new floor down etc. Just never gone on top of one, or had to weave into a floor where it had been done. Before all the chicago comments start LOL

If you need to use 1/4" plywood to raise up the subfloor height to meet up to the other, the staples I would recommend are 18 gauge with 1" or 1&1/4" legs and a 1/4" crown. These will not blow through as easily as 16 gauge with 7/16" crowns, IMO. You may also wish to use some subfloor adhesive as well. Staple 2" around the perimeter and 4" in the field. If you need 3/8" CDX, you could go up to those 16 gauge 7/16" crown staples. The adhesive is not required but cannot hurt either. On 3/8" CDX with the 7/16" crown staples, staple 4" at the perimeter and 6" in the field. IMO, one cannot use too many staples. Always use enough to have the underlayment solid and noise free.

Thanks gary, and I will be using glue