Installing Bellawood ¾” Solid Wood Over Concrete?


Many homes are on a concrete slab and a big question we often get is how to install over concrete.  So I asked our great guys over at Tech & Install to give us some ideas on how to install 3/4" solid Bellawood over concrete.

1st method: Floating plywood subfloor system:

Concrete should be clean and level up to 1/8″? over 6′. Apply a 6mil mil poly sheeting over the concrete overlapping the seams 6 inches and tape with duct tape.  Install a layer of 1/2″? plywood over the poly sheeting. Next install a second layer of 1/2″? plywood at a 45 degree angle to the first layer. Screw the top layer of plywood to the bottom layer. Be sure not to penetrate the poly sheeting with the screws.  Allow for a ½”? expansion space between the plywood and any walls and 1/8″? gap between square edge plywood panels. Last install 15lb black roofing paper over the plywood and install the flooring over the roofing paper. When installing the flooring use 1 ½”? fasteners to prevent nails from going through the plywood.


2nd method: Elastilon underlayment:

Elastilon is a 1/8″? thick underlayment with a self adhesive system.  To use this product over concrete you will have to apply a 6 mil poly sheeting over the concrete first, overlapping the seam 6″? and tape with duct tape. Roll out the Elastilon perpendicular to the direction of your floor installation. Butt the seams of the Elastion together (do not overlap). Next begin your installation of the flooring following Elastilons’ installation instructions. When using Elastilon cull out badly bowed or twisted board and add 15% more wood for waste.

ELASTILON underlayment installation



  1. Hey Raven, In order to install a wood floor properly over the Elastilon underlayment the instructions should be followed carefully and proper expansion break is a must for big rooms. If you were to install the 50ft section going with the long length of the floor boards and not the width, you can go 50ft without adding a transition break. When dealing with a 5″? wide plank I like to put transitions in all doorways. This will allow extra room for the floor to expand. In any case the instructions should be followed. The following paragraph is from the Elastilon installation instructions: "Expansion joints will also need to be installed in doorways, long hallways, and larger areas more than 33 ft (10 m) in length following the direction of the small width (eg. 3.5" width) of the floor boards. Additional Expansion joints are NOT necessary in the direction of the long length of the floor boards (and expanses longer than 33 ft are permitted). A small amount of white carpenters glue (PVA) must be applied to all adjoining ends (small ends of the boards). I hope this helps. If you need more instruction, just let us know. Thanks for your inquiry!

  2. The flooring industry always needs advice. I’m in a different area of flooring and when new technology and processes come out we need info like these blogs to help us navigate. Thanks Lumber Liquidators for keeping us up to speed. Very clean instructions.

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