Sound suppression under tile floor

[ford33]

I am installing ceramic tile flooring in a second story condo. The floor substrate is exterior grade plywood and the existing floor covering is carpet with pad. Although the condo board does not require noise reduction material be used under tile, I want to avoid noise complaints from the first floor resident.

I have seen products offered for under-tile installations but they all seem expensive. Some are as low as $2.50 per sq foot with many much higher.

I am not looking for a decoupling mat as that provides no noise suppression.

Anyone have a recommendation for a suitable noise suppressant underlayment product for use with ceramic tile? Or a supply source for such material in the Chicago area?

Remember this is a tile floor and requires a sturdy firm underlayment or the tile and grout will certainly crack. Waterproof is not a requirement. Tile size is 16X16 if that matters.

 

[JStar4]

So are you going to use 1/2 concrete board under and you also want another layer?

 

[ford33]

Yes, concrete backer board in addition to the noise suppressant layer. The concrete backer board does not provide noise reduction to any extent.

 

[ard]

The physics of this are tough.... Tile want a rigid substrate for tile....but noise abatement demands a compliant layer. If you have a inch and a quarter or more, you could lay a sound board, however I'd then do a mortar bed (which is self supporting, no fasteners to the wood) on top of this. I prefer mortar beds anyway.

 

[ford33]

Ard, not sure what you are suggesting. Are you suggesting putting the sound suppressant underlayment onto the plywood subfloor then tile on top of that?

I found a product from Proflex named MSC 90. It is a 90 mils thick flexible matt that is glued to the subfloor and then mortar applied to the top of the matt then tile. I called Proflex tech support and they stated that using it with backer board is acceptable but not required if the subfloor floor is already 1-1/4" inches thick.

Their matt goes under the backer board. Trouble is that it is expensive and they did not provide information on how the backer board is attached to the matt. I believe if I drive screws through the backer board then into the matt and subfloor that would defeat the sound suppression of the matt. As the screws would transmit impacts directly to the wood subfloor.

Anybody else have knowledge of impact sound reduction for flooring in multistory buildings with wood subfloors?

 

[ard]

something like homaste 4x8 panels:

http://www.homasote.com/products/440-soundbarrier

But then a totally isolated mortar bed over top.

The key is to not have your tile attached to the plywood floor. If you are stuck with pre-cast tile backer boards, ALL of them need to be clamped down to the wood. Defeating the isolation. (as you point out)

A mortar bed can sit on top, isolated. Its not hard. Read, google, youtube.