Delta-FL "The Warm & Dry Floor Systm
I recently installed a floating floor over a Delta FL membrane without plywood. And I’ll try to describe my experience. Of course it works but certain rules should be followed…
1. The concrete subfloor should be well prepared, this is true for all installations method but it’s more important if you don’t use a plywood or OSB because their rigidity dampens the concrete imperfections. So take a 3 feet level or something straight and level with cement any differences that exceed ¼ inch. In my case I only levelled the major imperfections and I regret this time economy.
2. I wanted to be sure the floating floor was to be silent so I installed a geotextile membrane (The kind of thick membrane used in landscape) between the concrete and the FL membrane with a nice success, not very costly and no click sound when walking over the floor.
3. Tape the joints to improve the air tightness.
4. If there is a slight gap in the concrete floor add a small part of Delta FL to level it (Doubling the FL membrane).
5. A common mistake is to use a plank with a broken snap on the side or even on the lengths. The floor contracts and dilate about ½ inch from winter to summer, If many planks are snapped and holds strongly together the contraction will necessarily takes place on the broken snap and the resulting gap will be displeasing.
6. The planks are sometimes made to be installed from left to right and the good side should face the wall, I started the wrong way and found it very difficult to insert the planks so read well the manufacturer instructions. You won’t have to start again.
Saves time and money. It gives a medium to good result.
The concrete sub floor has to be levelled more.
There is more swing in the finished floor without the plywood or OSB.
Why to use this membrane? Gives a protection against little water infiltration, like a leaking water heater, it will go under the wood floor without destroying it. The membrane is resistant to pressure, in fact it’s more resistant than the planks, so the planks will break before the Delta FL crush.
Between the planks and FL I used laminated foam, it’s good but not resilient and easy to flatten, it doesn’t come back to its position after flattening. I have grand piano, about 500 pounds, it’s supported on three legs, that’s 165 pounds on each legs so to limit the pressure on the planks I bought three 8x8 inch iron plate. Otherwise it was too much for the planks. If you have heavy furniture’s think about putting something under it.