What does "Level flat to 3/16 per 10 foot radius" mean?

Question

I am looking at USFLOORS CoreTec Plus installation instructions (http://www.usfloorsllc.com/wp-content/uploads/2014/07/USF-COREtec-Plus-Angle-Tap-Installation-Instructions.pdf) and it says

Level: flat to 3/16" per 10-foot radius".

What strictly does that mean?

For example, If I have a circle room 10 ft radius, and it is perfectly flat everywhere except one 2 ft wide 2/16" deep dip, does that satisfy "3/16 per 10 foot radius" requirement?

That seems like an overly narrow tolerance to limit warranty liability. :) — DA01, Nov 02 '15 at 16:49
I had LVP installed by a contractor and floor moves noticeably. In order to force the installer to correct the defects I need to measurably demonstrate that installation has not been done up to manufacturer's specs. — THX-1138, Nov 02 '15 at 22:54

score 3 · Accepted Answer · answered Nov 02 '15 at 15:34

No that doesn't satisfy the requirements necessarily. 3/16" over 10' is the allowed variance in slope. That means you are allowed 3/160" every foot, not the 10/160" that you are stating.

The abruptness of your use case is what would worry me the most. For instance if someone had a flat room and then it went up by 1/8" over a two feet span and then continued flat after, I wouldn't be overly concerned about that (althought I would probably throw a few feet of leveler down the day before install). A lot of installers would just shim some underlayment or shingles here.

Having a dip is a different story because where does the pressure go? Every time that you walk on that section the wood will "bounce". Depending on the install method and wood it could eventually fail. At best it is an odd spot on the floor. For an area like this I would DEFINITELY fill it with leveler. This is just $20-50 to make you feel a lot more confident in your install.

The document states 10' radius. Does it mean that acceptable slope shall be less than 3/16" over 20', not 3/16" over 10'? — THX-1138, Nov 02 '15 at 17:44
3/16 for 10' - which DA01 correctly comments that this is a very rigid allowance for a flooring install. You do want to patch your dip though. Your floor being flat is the key (not slope), the variance isn't such a big deal unless you have ridges - which it seems you do. — DMoore, Nov 02 '15 at 20:57

score 0 · Answer 2 · answered Nov 02 '15 at 14:48

0

It means exactly what it says. So long as 2 < 3 a 2/16 dip is less than 3/16, so spec is met.

When 2>3, you can try to run for the hills, but they might be valleys at that point, or oceans, or black holes into the void...

answered Nov 02 '15 at 14:48

Ecnerwal

213,340
10
261
571

2

So, if my room will have 1/8" variation across the floor every 7" (the width of the plank), the installation will still be correct? Even though every plank will be moving 1/8" when you step on it? – THX-1138 Nov 02 '15 at 14:54

What does "Level flat to 3/16 per 10 foot radius" mean?

2 Answers2