Axiom Home Page Forums General Discussion Technical Questions basement HT- cement floor.

Just wondering if someone can give me some ideas for dealing with the cement floor in my new HT room. Any ideas on constructing a wooden subfloor?

You may want to ask this over at the AVS HT Builder Forum (below)

AVS HT Builder Forum

I saw a product at either Lowes or Home Repot last weekend made just for that.

They look like 2'x2' OSB panels (oriented strand board) that have 1/2" diameter x 3/8" tall (maybe 1/2"), round, black, rubber, bumpers all over the bottom of them. The edges of them have tongues and grooves on them. You just set them on the concrete, tap them together with a rubber mallet, and then carpet over the whole works.

I cannot for the life of me remember the name of the product.

why would it be bad to leave cement under the carpet? What are the benefits of adding a wooden sub-floor? Thx.

Hi Althea,

You want surfaces that move somewhat, that are able to flex a bit, like a wood sub-floor, with wallboard on the walls. Concrete is the worst kind of surface for getting good sound, because it doesn't absorb any of the energy modes from standing waves in the bass (concrete is immoveable), so they build up and resonate in the room.

That's a good question. If the cement floor is is good condition, then you should ba able to install carpet (and padding) directly on top of it. Just make sure there the cement is dry and you have no moisture problems.

Wouldn't carpet and carpet padding installed directly over the concrete be enough to absorb the bass energy?

Peter,

I don't know for sure, never having had to deal with this sort of installation personally. However, a fellow editor of an A/V publication in Canada told me his nightmarish story of having a poured concrete home-theater room and only later learning that he should have put down a wood sub-floor and normal studs and wallboard.

Regards,

The primary reason that some homes need it is that moisture can come up through the concrete in some circumstances. I know that when I was reading ceramic tile installation books, they always mentioned taping a 12" square of clear plastic to the center of the floor with duct tape sealing all 4 edges. They said to leave it there for a few days and then peel it up. If there is a damp patch in that spot, they recommend installing some sort of subflooring before tiling. It has to do with the ground water pressure in your area. I'de think this would be more important with a carpet installation to prevent a musty smell.

When I go to HD or Lowes this weekend, I'll get the product name. I'm sure that we can find literature explaining it's useage on the net...

I just ran a Google search on tile +concrete +plastic +moisture.

Here is the very first article that I clicked on

Considering our basement is concrete on one wall, studs against concrete on 2 others, with a thin berber carpet on top of...yep, concrete, i can attest to the rather bright (reflected) sound.
Having moved my speakers into a friend's basement which had a more 'normal' room finish forwalls and floors, any and all brightness i ever experienced with the speakers in our house had disappeared.
I'm very excited about the concept of moving in the future and being able to look for a house that has a more suitable environment for our setup.