Springy laminate floor because of high-performance underlay?

[tmasa]

Hi

Half finished fitting laminate floor (Kronofix) in our living room and noticed it feels sort of springy/bouncy when walking on it. I used the high-performance underlay from Homebase (http://www.homebase.co.uk/webapp/wc...ay?langId=-1&storeId=20001&partNumber=1630864) to reduce the noise as this is the main walking path in the house.

Having read other topics and flooring FAQs in internet it seems that this sort of problems is normally caused by the sub-floor not being flat or floor expansion. Neither former nor latter applies, as this is a new installation (week old) and the sub-floor seems to be flat enough.

Can it be the underlay (see the picture attached) which hasn't flattened yet ? Will it settle down eventually ?

Untitled

• tmasa
• 5 Aug 2010
• 1

Looking at the picture on Homebase website it seems that this is how it should be laid ..

Thanks!

 

[big-all]

heeelllooo and welcome tmasa

you need a long strait edge to check more than 2mm up or down can cause this problem

you have a 12mm expansion gap all the way round with nothing in it !!
you have undercut the door frames and architaves or left a gap!!
you have used joining strips in door way with 12mm expansion underneath!!
you have no run greater than 4metres without an extra expansion join!!

 

[WoodYouLike]

you have no run greater than 4metres without an extra expansion join!!

Eh, only when you install Solid wood flooring this rule of thumbs apply. Laminated is not even real wood and can - like wood-engineered floors run up to 11 meters wide before needing an extra expansion joint.
You're right on the other points

As for the bouncing, your underlayment - no matter what type of underlayment - needs to lay flat, especially underneath thin laminate flooring that has/can have a lot of flex of its own.

Didn't the Homebase stuff come with instructions of use????

 

[tmasa]

Thanks for your replies.
Please see my comments below.

you need a long strait edge to check more than 2mm up or down can cause this problem
=== nope, measured it this way - seems to be flat

you have a 12mm expansion gap all the way round with nothing in it !! === I have 15 mm all around

you have undercut the door frames and architaves or left a gap!!
=== undercut

you have used joining strips in door way with 12mm expansion underneath!!
=== no strips there yet, gap - just started

you have no run greater than 4metres without an extra expansion join!!
=== it is 3x3 meters so far

Didn't the Homebase stuff come with instructions of use????
=== yes but it is as simple as "put it silver side up and seal together", does not say anything about unevenness in places where it used to bend while packed flat, as on the picture

I used the cheap white one from IKEA in other rooms and it feels much firmer, but it is softer and probably straightens faster under the weight of the floor

 

[WoodYouLike]

Didn't the Homebase stuff come with instructions of use????
=== yes but it is as simple as "put it silver side up and seal together", does not say anything about unevenness in places where it used to bend while packed flat, as on the picture

I used the cheap white one from IKEA in other rooms and it feels much firmer, but it is softer and probably straightens faster under the weight of the floor

The cheap one no doubt come on a roll? And your laminate floor hardly has any weight of its own. Trust the DIY-sheds to explain as much as they did when selling you stuff!

I think the ridges of the underlayment are causing you this bouncing problem. And I hope for you that once the furniture is in place it will start to "flat out".

 

[big-all]

you have no run greater than 4metres without an extra expansion join!!

Eh, only when you install Solid wood flooring this rule of thumbs apply. Laminated is not even real wood and can - like wood-engineered floors run up to 11 meters wide before needing an extra expansion joint.
You're right on the other points

ok being lazy
i normally tell them over 4m you should look at further expansion gaps
over 6m i wont lay without the option off being able to introduce further expansion gaps in doorways iff needed at a later date in case off problems

11m WOW have you laid many that big without comeback!!
not doubting what you say just a new one on me lol

 

[WoodYouLike]

11mm wide with quality wood-engineered floors (and the right expansion gaps every where), to be honest: only twice - but never had to go back to sort things.
Keep the 4 meter warning whenever you have solid floors though

 

[Petest67]

Looking at the photo it seems that there is a peak in the chipboard and a void to either side under the laminate (gap between the laminate and underlay) - if this is the case then it will spring as you walk over it.

 

[mac391]

I think big-all's coment about the use of a straight edge might show you your subflloor is probably uneven, you can't tell if a floor is flat by looking at it, you have to check !! A few mm is enough to cause your laminate to bounce. Also what petest67 mentions about a peak being there sorta proves the point !! Your subfloor is uneven.

 

[tmasa]

I think big-all's coment about the use of a straight edge might show you your subflloor is probably uneven, you can't tell if a floor is flat by looking at it, you have to check !! A few mm is enough to cause your laminate to bounce. Also what petest67 mentions about a peak being there sorta proves the point !! Your subfloor is uneven.

Yep, did more measurements in different areas and directions and it seems to be uneven by up to 5 mm in some places.

Is it too bad ? You can't really feel that it is bouncy while walking, one can only see from the perspective that it is actually waving.

 

[big-all]

other things that can cause problems tack screw nail sitting proud grit or foreign object and folded/trapped underlay
so you need to look for high points in the laminate as well as low points on the floor