Flooring Question

Laminate on uneven floor

Hi there

I have a room that is both floorboards and concrete. About 2/3 of the room is floorboard, and 1/3 is concrete (on the edge). Now the concrete is slightly higher than the floorboards, creating a slight dip as you walk over it.

I am going to install laminate using fibreboard underlay.

I realise there may be slight dip and I am ok with this, but in your experiences, would the laminate crack or break in future? I am hoping it does not, especially after using fibreboard underneath.

Thanks in advance

9 Answers

Best Answer

Could you not lay hardboard on the existing floor boards to raise the floor to the same as the concrete floor that will solve the dip but it all depends on the hight difference. laminate wont snap or crack as its rather robust unless it's the less expensive and very thin stuff. But it might be a bit bouncy in the area of the dip.

Answered 6th Jan 2012

Smiths Property Services

Member since 4 Jan 2012

It is very likely to creak, my advise would be to gun out the concrete and lay some leveling compound over the top

Answered 8th Jan 2012

House Doctors

Member since 13 Jul 2011

Hi Amrit.
If the differential in levels is more than 3mm you will generally find that flooring manufacturers recommend leveling. Although the laminate will most likely not crack you will end up with a horrible bounce in the floor.
As it is the timber floor that is lower you will need to use a flexible floor leveling compound, there is a product on the market called Green bag. Using a straight edge of about 6ft you would be able to feather out the step until almost unnoticeable.
Hope this is useful to you.

Answered 7th Jan 2012

First Choice Construction

Member since 22 Feb 2011

No feedback

Hi amrit,

Depending on how slight the dip is??? It is probably best, to try and flattern it out. Laminate has a habit of cracking along the joints, if the floor is uneven. It might take a few years though. Fibre board undelay isn't any good on screed (concrete), it will be ok on the timber part of your floor. Maybe try a slightly thinner moisture barrier underlay for the concrete... and try to level it that way, or try a floor leveling compoud or hardboard before fitting your underlay.

Kind regards


Answered 6th Jan 2012

Rebel Carpenter

Member since 24 Sep 2008


I have layed many a laminate floor and yes if your subfloor is not sound and level, you can expect laminate to part at the joints. You could be lucky but why risk it. Find something to bring up floorboard level to concrete then comence.

Answered 7th Jan 2012

L B Services

Member since 29 Dec 2011

try fitting ply or hardboard to the floor boards first to bring the hight up

Answered 7th Jan 2012

Max Barnard

Member since 4 Nov 2011

I wouldn't say the laminate would'nt break as its made of Stearn stuff, why don't you lay some hardboard on the wooden floor to bring it up slightly??,,if you do it needs to be fixed every 6 inches in all directions. If by doing this the hardboard is slightly higher than the concrete you could always use floor levelling compound on top of the concrete to make up the difference....

Answered 8th Jan 2012

ABM plastering

Member since 21 Feb 2011

yes it would crack after a few months, you should not lay over the dip, why don't you try raising the floorboards depending on how much the differance is by use 3, 6, 9mm plywood sheets as long as you secure these to the floorboards it will give you a level floor.

Answered 6th Jan 2012

BuildIt Construction

Member since 4 Jan 2012

it possibly could, to be safe lay hardboard (3 to 5mm)or osb (6 to 9mm) over the lower area to level them off a bit and then lay the laminate over the top on the fiberboard underlay.

Answered 6th Jan 2012


Member since 21 Nov 2011

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