I'm about to lay a lamintae floor in a long room - almost 8m by 3m.

The room was created by adding a partial house extension about 6 years ago
and has a floating chipboard floor. The floor is sound in that there are no
'steps' between the boards and therefore appears flat. However, close
inspection reveals a 'crest' hlafway down the room. One half of the room
appears to be slightly higher than the other. The chipborad the falls away
before leveling towarsds the other end. In short it appears that the orignal
room is slightly lower than the extension part. I would guess the difference
in height between the two rooms is about 15 - 20 mm, the transition taking
place over 2 to 3 metres in distance.

This appears to be beyond the recomended tolerance of what is considered a
'flat' floor.

Question is what do I do about it?

What appeared tobe a relatively simple job of laying the laminate is now
looking not quite so simple. I have perchased some accoustic deadening
underlay from Quickstep (2 mm thick). Would the 7mm fibre board underlay
compensate better?

If I go ahead and lay on this floor what sort of problems will it create? My
main worry is if the gaps between the laminate 'open' as a result of the
uneven floor and then then laminate begins the chip away at the edge.

Is there is straight forward way of leveling the floor without ripping the
whole thing up and starting again. To my knowledge the chipborad is laid
straightonto polystyrene insulating blocks about 2 inches think which in
turn lay on the a comcrete floor.

Any thought/suggestions would be most helpful.
Thanks

Geoff

Geoff wrote:
I'm about to lay a lamintae floor in a long room - almost 8m by 3m.

The room was created by adding a partial house extension about 6 years ago
and has a floating chipboard floor. The floor is sound in that there are no
'steps' between the boards and therefore appears flat. However, close
inspection reveals a 'crest' hlafway down the room. One half of the room
appears to be slightly higher than the other. The chipborad the falls away
before leveling towarsds the other end. In short it appears that the orignal
room is slightly lower than the extension part. I would guess the difference
in height between the two rooms is about 15 - 20 mm, the transition taking
place over 2 to 3 metres in distance.

This appears to be beyond the recomended tolerance of what is considered a
'flat' floor.

Question is what do I do about it?

What appeared tobe a relatively simple job of laying the laminate is now
looking not quite so simple. I have perchased some accoustic deadening
underlay from Quickstep (2 mm thick). Would the 7mm fibre board underlay
compensate better?

If I go ahead and lay on this floor what sort of problems will it create? My
main worry is if the gaps between the laminate 'open' as a result of the
uneven floor and then then laminate begins the chip away at the edge.

Is there is straight forward way of leveling the floor without ripping the
whole thing up and starting again. To my knowledge the chipborad is laid
straightonto polystyrene insulating blocks about 2 inches think which in
turn lay on the a comcrete floor.

Any thought/suggestions would be most helpful.
Thanks

Geoff





I'd use a straightedge (about 2.4 m should be long enough) to get an
idea of where the high/low spots are and how gradual the fall is etc.
You could try a self levelling screed to even things out. Chipboard is
not the ideal surface for it but, sealed with pva, it should take ok.
You can't alter the fall but you can make it smoother and get rid of
obvious ridges. 20mm over 3 metres doesn't sound like too much of a problem

Stuart Noble wrote:
Geoff wrote:
I'm about to lay a lamintae floor in a long room - almost 8m by 3m.

The room was created by adding a partial house extension about 6 years
ago and has a floating chipboard floor. The floor is sound in that
there are no 'steps' between the boards and therefore appears flat.
However, close inspection reveals a 'crest' hlafway down the room. One
half of the room appears to be slightly higher than the other. The
chipborad the falls away before leveling towarsds the other end. In
short it appears that the orignal room is slightly lower than the
extension part. I would guess the difference in height between the two
rooms is about 15 - 20 mm, the transition taking place over 2 to 3
metres in distance.

This appears to be beyond the recomended tolerance of what is
considered a 'flat' floor.

Question is what do I do about it?

What appeared tobe a relatively simple job of laying the laminate is
now looking not quite so simple. I have perchased some accoustic
deadening underlay from Quickstep (2 mm thick). Would the 7mm fibre
board underlay compensate better?

If I go ahead and lay on this floor what sort of problems will it
create? My main worry is if the gaps between the laminate 'open' as a
result of the uneven floor and then then laminate begins the chip away
at the edge.

Is there is straight forward way of leveling the floor without ripping
the whole thing up and starting again. To my knowledge the chipborad
is laid straightonto polystyrene insulating blocks about 2 inches
think which in turn lay on the a comcrete floor.

Any thought/suggestions would be most helpful.
Thanks

Geoff





I'd use a straightedge (about 2.4 m should be long enough) to get an
idea of where the high/low spots are and how gradual the fall is etc.
You could try a self levelling screed to even things out. Chipboard is
not the ideal surface for it but, sealed with pva, it should take ok.
You can't alter the fall but you can make it smoother and get rid of
obvious ridges. 20mm over 3 metres doesn't sound like too much of a problem


Id actually use very thin battens, to lay out a dead level grid, and
fill the rest with levelling compound.

Ive used Kahrs here, and you DO notice even minor slopes and bumps. The
good news is that waht goes under it doesn't get a lot of stress.

Geoff wrote:

Any thought/suggestions would be most helpful.
Thanks

Our lounge/kitchen/diner was knocked about to make an open plan affai.
12m x 4m
There are 3 distinct "steps" to the floor each step being perfetly flat
across the joists. the steps occur on a joist basis so 1 third was
level, next third was at least 8 to 10 mm higher from there it was
level until the next step.

All I could do was chipboard over the lot and hope the laminated wood
floor would make up for what the chipboard left behind.

the wood floor I used is engineered wood "khars" which locks together
the same as mdf laminate.

The chipboard and flooring (no underlay worth mentioning) have evened
out the steps almost completely you might need to chase a marble across
the floor, but that's the only way you'd know.

I think you'll find as long as the hump has been evened out by the
chipboard your laminate will cover without any problem.

On ours I did lay the boards 90 degrees to the chip board, so parallel
to the offending joists below. This was for aesthetic purposes more than
anything, but may well have helped having a joint every 8" in the same
plane as the problem. If that makes sense.

Pete

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