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Installing Nail Down Engineered Wood Floor

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Nov 08, 2013, 08:42 PM
Sparkaholic
Installing Nail Down Engineered Wood Floor
hi, i am getting ready to install a nail down engineered wood floor. I read the instructions and it says to leave a 1/2 in expansion gap around the perimeter of the room. I understand the concept of the wood expanding with moisture, etc. But if the engineered wood floor is nailed down every 6-8" into the subfloor how is it going to expand 1/2" without cracking the wood or buckling with the nails in it? I am going to leave the gap I am just curious about this.
Nov 09, 2013, 12:28 PM
nona
remember, the wood wont expand in only one direction but will expand both ways equally, or 1/4 " left and 1/4" right. so leaving the gap is needed. perhaps you could get away with a smaller gap but 1/2" is standard
Nov 09, 2013, 07:12 PM
Jaybee
If the moisture level changes in the flooring enough, it is going to expand or contract. No amount of screws or nails can stop this. In most cases, engineered flooring is very stable and will hardly ever move. Leaving the 1/2" gap is just an easy safeguard to cover all the bases. If you are installing hardwood, you will have a base (5/8" thick) and shoe molding (3/8" thick) so you'll have a minimum coverage or 1".


Jaybee
Nov 11, 2013, 11:46 AM
swschrad
put a nice foam-roll sound deadener underneath the floor, too. no, it's not needed, rosin paper or tar paper is "good enough."

when I'm dumping that kind of money into my own house, "good enough" doesn't cut it. as a result, there is no clickety-click walking across our floor. and the time or two I had to pull some up where the previous cat had not-accidents, it was easier to get up, as there was a little more give for the prybar going underneath.


sig: if this is a new economy, how come they still want my old-fashioned money?
Nov 11, 2013, 04:48 PM
Jaybee
Actually, while a foam underlayment is great for floating floors, you don't want that with a nail down. If you have something with some thickness like foam, then a weight concentrated in one area can compress the floor into the foam. Then, when the weight is gone, the floor will rise back up. Up and down movement in a nail-down floor is a bad thing, leading to loose and squeaky floors.

The purpose of layer between a nail-down hardwood floor and the subfloor is to isolate the two so that any slight movements will not squeak. for this, a thin layer of underlayment works best.


Jaybee
Nov 11, 2013, 05:51 PM
swschrad
haven't seen any issues, Jaybee. this is barely foam, closed-cell, perhaps a 16th of an inch, the blue underlayment. but then, you pay the bills doing this, so if you prefer tar paper, no argument here.


sig: if this is a new economy, how come they still want my old-fashioned money?
Nov 11, 2013, 11:24 PM
Jaybee
It's one of those 'eventually bad things will happen" things. If a nail down floor can be compressed, that means that the nails are moving up and down in relation to the flooring. Loose nails lead to floor squeaks as the nail actually stays in place and the floor rides up and down on it. 1/16" isn't much, but it's enough.


Jaybee
Nov 12, 2013, 12:30 PM
SturdyNail
Jaybee, when you said "a thin layer of underlayment works best", were you referring to Luan, rosin paper, or tar paper?

Thanks.
Nov 12, 2013, 01:29 PM
Jaybee
Rosin paper or 15# felt are most common. There is a newer synthetic roofing underlayment that works well too.

Lauan would add an actual structural element to the floor and would need to be nailed down separately - no reason to use in underneath a nail-down hardwood floor. Lauan would be used to smooth out a rough subfloor to prep it for sheet vinyl.


Jaybee