Why not use shorter 1 1/2" staples (or even 1") staples on a 3/4" solid TG hardwood over a 3/4" subfloor?
Seems like 2" is just wasted!
Thanks Frank

1.5" is probably fine. That's what I used. Some things to keep in mind: (1) the staples are going in at a 45 degree angle, so comparing the length of the staple to the thickness of the wood and underlayment is not accurate. (2), the staple typically goes in on the top of the tongue, about 1/4" lower than the surface, so again, looking at just the total thickness is not enough.

So, if you had 3/4" solid and 3/4" ply, the distance from where the staple enters, to the bottom of the ply, at a 45 degree angle is sqrt( 1.25^2 + 1.25^2) = 1.75". I used 1.5" staples because I did not want to poke holes the in the vapor barrier I had below the 3/4 ply (and above a concrete slab).

I really appreciate the solid math answer.
Wish I got better grades in math and geometry
Frank

AMT
sqrt( 1.25^2 + 1.25^2) = 1.75".

Does the 1st 1.25 represent the .75" plank minus .25" for the tongue?
Whats the second 1.25" represent?
Frank

http://en.wikipedia.org/wiki/Pythagorean_theorem

;D

Frank,

I used 2 inch staples because I was tring to hit the floor joists to compensate for a too thin subfloor. I bought my floor from Lumber Liquidaters. I had to buy an extra two boxes because of the high number of rejects. Some way too light (almost white) and some way too dark (almost black. There was also a problem with the width on some of the 12 in and 18 inch boards. I ended up with about 50 feet of rejects left over and plan to put it in the master closet. The floor is very nice and we are happy with the finished floor.

Darryl

I have been trying to figure out the length of staples to buy based on what I read on this site and the answer still does not make sense. I read you don't want them to break through but it is recommended over and over to use 2" staple with 3/4" flooring and 3/4" sub-floor. A two inch staple on a 45 degree angle through 1 1/4" of flooring (3/4" hardwood and 3/4" sub-floor minus the 1/4" depth of the tongue= 1 1/4" ) is going through the sub-floor by almost 5/32". The math has the depth come out at 1.414 which means it has gone through and using that same math a 1 1/2" staple has only gone 1.060 deep which seems a little on the shallow side. So what is the answer, PRETTY PLEASE!

formula I use is 45 degree sin x 2.0 = 1.414
" " " " " 1.5 = 1.060

Greg

This link will show you how deep different staples go into different woods

http://www.powernail.com/home/staples.htm

Thanks for posting that page, it shows what I calculated with math. It does not answer the question about breaking through the sub-floor. I think I will go with 1 3/4" unless someone gives me a reason to use something else that makes more sense. The 1 1/2" just don't seem long enough for good holding power.

Greg

This may not change your mind Been using 1 1/2" for what seams like forever. Plenty of holding power.

2" fasteners are carried on from old 33/32 flooring of days long ago.

When a fastener blows through the panel, it loses ½ of its holding power.

I forget the correct term, but something withdrawal.

My last question on length, would it be better to go long and hit the floor joists with half or more of the staples or go short an rely on the sub-floor thickness for good holding power and not take the extra trouble to hit floor joists every 16".

Greg

A 2 " staple pops through the subfloor only about ¼" That's some real holding power!!

Now, if you were using 3" fasteners at the joist, you might accomplish something.

A waste of time and no benefit.