Hi all,
I've been reading and searching the forum for a while now and can't seem to get a definitive answer to my problem!?

Basically we wanted to replace the old tatty carpet with a nice wood floor in the "playroom". I was planning a DIY install to keep costs down and we got a really good deal on some clearance Kahrs Oak (about half price!) and Tuplex underlay. Anyway I ripped up the carpet and the concrete slab underneath looked pretty good to the eye so I put the underlay down and started laying (about 5 strips). It quickly became obvious that the subfloor wasn't flat because the floor was bouncing quite badly in a few places so I took it up and got my 3ft level out and confirmed that in a few places the dips were as much as 10mm. So I concluded that I needed some self-levelling concrete and thought about doing it myself but instead phoned a "pro" to come and do it, which he did (hard latex type stuff!). He also commented that the Tuplex underlay was a bit rubbish but to give it another go. So this time I did the the whole floor, and again in a few spots the deflection was really bad. One part (near the wall) was so bad that when you stood on it you could hear the "chuffing" of air bellowing out from under the floor. So I got the guy back who spent a while pacing over the floor and he concluded that the minor areas that were bouncing would sort themselves out over time as the floor "settled" but the chuffing area would "probably" be okay once the skirtings were put back on but that if I wasn't happy with that then he would come back and put another load of levelling over these bad areas (which he did at no extra charge). He also suggested I get some better underlay as he had no experience with Kahrs Tuplex but commented that it didn't look up to the job. So I got some Boardwalk Tredaire (I think with the shiny gold foil on one side!?). Incidentally he also pointed out that he was unlikely to be able to get it "perfect" and that sometimes you just have to know when to stop trying to get it flat as you risk making it worse (which seems like a fair point!?). He also said that the areas which bounce and ripple slightly will eventually sort themselves out as the engineered wood settles into the minor depressions.

So the situation now is that the entire floor is down with the "decent" underlay. Some areas are rock solid with no deflection whatsoever, but a lot of it does "give" slightly and I can feel it (only a bit) as I walk over. You can see it more if you are sitting down and someone walks over it that it sinks and ripples in quite a few areas. Will this settle down over time or is this par for the course for a floating floor? My wife is fed up and has moved the stuff back in and thinks its fine, but it is definitely bugging me!

Annoyingly there is another area (near the door this time!!) that deflects a lot (it's the last few strips by the wall) and again you can hear the air chuffing as you step on it. Because it's near the wall I was hoping that when I put the skirtings back on I can push the skirtings down onto the floor to "hold it down" so that it can't deflect back up - would that work?

So is this about as good as its going to get with the floor ie a bit bouncy and ripple-y in a few places or will the floor eventually settle as my floor-levelling-guy has suggested?

What about the "chuffing" area - will my "skirting fix" sort it out?

Sorry for the long post and thanks again for all your help!?

Matt

floating installs will always have some deflection that's just the nature of the beast with that type of installation. Furniture and baseboards will reduce the movement. Khars has a beefy locking system so it can be a bear to fully engage the locking sysytem near the wall and especially on rip cuts.

Matt,

First the Kahrs product has been successfully installed over Tuplex or the product is also branded under the name Kahrs Combo foam on many millions of square feet globally without a problem. The Kahrs brand of wood has since1857 produced products that are documented to be the lowest claims ratio in the industry. With that said speaking of the Tuplex/Kahrs Combo system has been 100% problem free since 2000.

Here are my suggestions:
1 Review the guidelines posted on the Kahrs website detailing proper preparation of subfloor, installation, environmental conditions and use of underpayment.
2 The floor should be flat within 1/8" in 8' (NWFA wants 3/16" in 10' which is the same)
3 Make certain the subfloor was firm to begin with
4 The boards must be staggered 20" between adjacent endjoint for dimensional integrity and to alleviate vertical movement along with adequate expansion provided around the room and any vertical fixed objects such as cabinets, columns, etc.
5 The 1/2 price deal that you received may raise the question of if the product was first quality

Hope that helps - canton
6 The folks at their 800 number have always been helpful. 800-800-5247

Hi and thanks for the replies.

Im wondering if my expectation of a floating floor is too high. The deflections are not too bad but they are noticeable. I think I was hoping that the floor would feel rock solid - and in some places it does but others, not. Is it really possible to get a rock solid all over floating floor installation?

What bugs me is that upstairs we have some v cheap laminate, and while it doesn't look anywhere near as good, it feels about the same!

Is it possible that the subfloor IS flat but somehow there is still slight deflections? I installed it myself and made sure that the boards were staggered enough (at least 50cm) and that they were properly engaged (with a plastic block and mallet).

Matt

That is possible....Like Kevin mentioned about the "beefy locking system" if not fully engaged. In traffic areas..that can sometimes settle in with time. Also...if some of the planks aren't as flat as your subfloor, that can take some time to settle in as well. May sound like a line..but I've witnessed it. Throw a party in the playroom...I'll bet it feels better the next day

I agree with Kevin and Floorologist. I see engineered bowed right out of the box and if your not careful to sort them out (culling) the floor will be bouncy, even may not flatten out. Other causes can be low or to high relative humidity causing the planks to bow. Improper moisture content of various plys during manufacturing.


http://www.tucsonazflooring.com

Pretty much all the planks were slightly bowed in a convex fashion but I have read somewhere that kahrs manufacture them this way but I don't know why.

So is it possible to have a COMPLETELY solid floating floor or will there always be SOME minor deflections here or there?

One other thing - is putting double layers of underlay under the worst areas just a botch or us it common practice?

Cheers,
Matt

Mat, I'll not admit to it but I know people who have shimmed out low spots with paper or cardboard before, but your risking a bump if the floor flattens out.



_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Floor Repairs and Installation in Tucson, Az

http://www.tucsonazflooring.com

Matt,

Once again rather than solicit opinions I would refer to the manufacturer's website at www.kahrs.com. They have made available the complete download library for any product that they produce from MSDS sheets to explicit installation instructions.
The boards do have a natural bow right out of the box and are manufacturered that way intentionally. The environment will have an effect due to the amount of temperature and humidity. Thus movement will happen as it won't be exact to the environment (carton) that it is shipped in. This is one of the reason for the 20" stagger between adjacent end joints. That stagger provides dimesnsional integrity and also forces each board to lie flat. The Kahrs product does not and the instruction clearly state do not acclimate the boards prior to installation as the packaging maintains the wood moisture content to allow for an effortless engagement of the mechanical tongue and groove configuration. The existing floor can be brought into specification by using any non-compressible material but never double foam underlayment. The foam underlayment is compressible and will cause a problem. According to the maunfacturer's instruction there is no reason to use a mallet to install their mechanical Woodloc system so I would again suggest visiting their site for installation methods that they reccomend. As I have read many facts in the comments throughout this forum there are also many that conflict with the manufacturer. I would defer to those that produce and test the products and installation methods under many conditions. Wood flooring is a lifetime investment and I have found that the manufacturer is usually the best source of information since they are the one's writing and backing the warranties based in climate chamber tests and various installation techniques.

Thank you all for taking the time and effort to reply!

I think there may potentially be a few issues here but my gut feeling is that the subfloor isn't quite right.

How easy is it to get it to the recommended flatness? My floor man has basically said this is as good as its going to get!?

Also will I ever get the floor to be rock solid all over or is this the price you pay for a floating floor?

Thanks again!

Matt, how did the installer check the floor flatness to begin with? There's a couple methods out there, one the ole 6ft straight edge, going both directions. Second the string and bucket method. Then there's the best method so far.
embed codes don't wotk here so your going to have to click on it to see the new Bosch laser.
http://youtu.be/2AUWh10LEfI




_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Repairs and Installation in Tucson, Az
http://www.floorsavior.com
http://www.tucsonazflooring.com

Hi! No he didn't use the laser! He used one of my kahrs planks on its side and said it'd be fine!
When I was considering doing it myself my plan had been to get a 6ft straight edge, mark the uneven areas with chalk then dollop some leveller on (I had planned to get the slow-setting compound to give me more time, and scrape the straight edge along concentrating on the dips. However I thought that I'd never done it before and might potentially make it worse so decided to get a pro in.

Matt

Well, I was skimming through the Kahrs site and they claim to deliver at 7% MC. So depending on your sites rh this could have an effect on the intentionally bowed planks. Hmmmm, never heard of a manufacturer intentionally delivering bowed planks but what ever. I didn't find that on their sites literature either. You would think if they did that it would behoove them to notify the consumer or installers.

I do agree a 20 inch stagger will help the stability of the system but it also can create much more waste. Personally I stay within the 6 to 9 inch minimum range which is the norm for the states unless otherwise directed in the manufacturers literature.

The laser is quite new and hardly available in the states so far. And it is quite expensive.

_________________
Stephen Perrera
Top Floor Installation Co.
Tucson, Arizona
Repairs and Installation in Tucson, Az
http://www.floorsavior.com
http://www.tucsonazflooring.com

My bet is the subfloor wasn't flat. I have never found one that is especially concrete. For that reason floating floors will never feel absolutely solid, that is just their nature. But yours sound like it was too far out of whack. If you wanted solid more leveling should have been done then gone with a glue down.

I am definetely curious myself in the reasoning behind the"intentionally bowed planks". The "effortless engagement of the mechanical tongue and groove", doesnt quite jive with the purposely "bowed planks" If you can help us with this Mr. Canton...would surely appreciate it. I'm also trying to figure out why a floor that is intended to lay flat, is manufactured "intentially with bowed planks", and then a specified stagger is requested to "force each board to lie flat"

"Once again rather than solicit opinions I would refer to the manufacturer's website" That's always a very good idea...and always suggested on this Forum, as well as researched by most contributors. I must say though...There are always unanswereed questions that hundreds of years, of combined job site experience, can lend some value


Howard Chorpash
Frazier Mountain Hardwood
Las Vegas, NV
http://www.lasvegaswoodflooring.com