Hi guys,

What would be my options on pre-fab concrete blocks that are not really level, we were thinking about doing 3/4" x 3" sleepers on the concrete and then nailing a 4" solid to the sleepers, however we can't do that now because the sleepers would only be able to run in the length of the room which would mean that the hardwood would have to run the width, which we don't want.

Having said that, what would be the cheapest and most economical way to put a solid 3/4" hardwood down in such a situation?

Can we pour gypcrete, level out the floor and then glue a solid 3/4" x 4" to the gypcrete? or do we have to level it out with gypcrete and still do the sleepers and nail the 4" plank to them.

If we can glue a solid directly to the concrete, which glue would you use?


Thanks

Dont believe everything you hear; you CANNOT glue solid to concrete, except as a patterned floor.
Why must the sleepers run the length of the room? I am trying to envision a circumstance that would make that necessary.

Because the concrete blocks are cupped and are really not even. Imagine a 5" plank thats cupped because of moisture, thats what the concrete looks like all over.

I think your best bet is to level the concrete. Then you can lay the sleepers then the floor in the direction you want.

If the concrete looks like that all over, you really cant use sleepers in any direction.

I would agree with Jeff. Level the concrete, and then go with the sleepers. Be cautious of the moisture readings in the concrete, always, and again after leveling . Before you install sleepers , & hardwood.

As the other guys said, you cant just add sleepers over these irregular slabs of concrete you describe. Flatten the concrete by grinding and using levelling compound as needed until you have acquired a flat base for the installation of the sleepers.
Starting out a project like this by skipping the first important step, will only lead to complications later on during the installation.