I spoke to two different Kahrs tech reps today who said that the Quiet Stride underlayment (which we had decided on) was to be used when you are trying to decrease the sound transmission to a floor below you.

They said that they recommended their combo underlayment when installing on a concrete slab (no one on a floor below) because there was no difference (except the higher cost) if you used the Quiet Stride instead of the combo underlay in terms of reducing the "clickiness" or the solidity of the floor. Any comments?

With whom did you speak?

I think the gentleman's name was John. I also spoke with a woman, but I did not write the names down. I called 1-800-ASK-KAHRS and spoke to their technical rep assistants.

Over concrete, you need the moisture barrier, wether it is separate or part of the cushion combo.

You want to reduce sound resonance? Cut out cushion and use contact cement to attach the cushion to the back of each plank, before you install it!!!

Grace,
I was just curious. They told you right. Quiet Stride shines on the IIC side, but is identical to the combo on the STC side. The combo is a 2-n-1, whereas Quiet Stride must go over polyethylene. The combo stuff is awesome.

Which do you recommend, considering price? We are installing on an above ground concrete slab. I noticed that Chuck had mentioned in previous posts that the Quiet Stride felt much more solid when walked upon. Is it worth the extra price? We realize we need a moisture barrier in either case, and are interested in as quiet a sound and solid feel as we can get. Thanks.

The only time I have heard a sound difference was when the cushion is attached to the planks. It is a very dramatic difference in resonance.

The solid feel is going to come from the floor prep you do or don't do, to get the concrete flat to specifications and requirements What is it, 1/6" in 6 feet or 3/16" in 10 feet. Pretty flat. Looks flat to me ain't going to cut it.

Floorguy, it's funny you said that. Two different prospective installers said EXACTLY that....."looks flat to me," and said the underlayment would take care of any irregularities, as well as "It doesn't look like you have a moisture problem" when we asked what moisture meter they used......

Chuck, do you recommend one over the other given the price difference? Thanks!

To tell the truth, I think Quiet Stride makes for a quieter install, but the numbers suggest that the difference is minimal.

I would trust the numbers. There is an awful lot of subjective stuff associated with floating floors. I am guilty of being biased in favor of quiet stride, but I cannot offer an objective reason for using it outside of multi-family applications.

I supppose I am destined to have an installer's outlook forever.