Floating engineered Oak - 3mm in 3m??

[GotWood]

More advice required please.

What is meant by 3mm variation over 3m?

Does this refer to dips/bumps, or to a change of level (i.e. one side of the room higher than the other)?

For example, I have a room which is flat (no dips/bumps) but of a consistent gradient making a 22mm drop over 3.5m - would this therefore be inside the 3mm/3m rule?



GW

 

[WoodYouLike]

What is meant by 3mm variation over 3m?

For example, I have a room which is flat (no dips/bumps) but of a consistent gradient making a 22mm drop over 3.5m - would this therefore be inside the 3mm/3m rule?

It means a gentle sloop of maximum 3mm over 3 meter long/wide (sloop in one direction, and no hills and dips in it)

Hope you mean your sloop is 2.2mm over 3.5m and not 22mm (2.2 cm)?

 

[GotWood]

WYL,

Thanks for your response. Sadly you read my post correctly, my floor slopes 22mm over 3.5m.

Is floating impossible then? Would glueing/nailing be better?



GW

 

[IJWS15]

As i unsderstand it the 3mm in 3m is the degree of flatness

nothing to do with it being horizontal.

If it is flat but sloped it should not be a problem, except that things will roll across the floor.

 

[WoodYouLike]

If it is flat but sloped it should not be a problem, except that things will roll across the floor.

It's not carpet we're talking about here, but rigid wooden flooring - see subject of post: Floating engineered Oak
This sloop is too steep, planks will not follow the "curve" and end up high above the deepest point of the sloop.

You have to flatten out the sloop to maximum 3mm over 3 meter if you want to install your wooden floor - no matter which installation method you plan to use.

 

[tall_tone]

If it is flat but sloped it should not be a problem, except that things will roll across the floor.

It's not carpet we're talking about here, but rigid wooden flooring - see subject of post: Floating engineered Oak
This sloop is too steep, planks will not follow the "curve" and end up high above the deepest point of the sloop.

You have to flatten out the sloop to maximum 3mm over 3 meter if you want to install your wooden floor - no matter which installation method you plan to use.

I would agree with IJWS15 here only if this room is a single entity. Then it could be any slope, 45 degrees for all the wood cares.
If you are flowing from one flat room into this room with a slope then I would agree with Wood You Like.

That said 22mm is well within levelling capabilities and it would stop people feeling the lack of level under foot (or stumbling) if it is sorted.

British Standard 8201 - 1987 states +/- 3mm over 3 meters, this is levelness for installation purposes and is quoted by most wood manufacturers. It is not a requirement for flatness of a floor.

TT

 

[GotWood]

This sloop is too steep, planks will not follow the "curve" and end up high above the deepest point of the sloop.

WYL: Can I be cheeky and correct your english?! It is 'slope' not 'sloop'

The floor is not curved; it is flat but not level: Imagine you lift one end of a table, for example. The new floor will be completely in contact with the old floor. Does this change your opinion on floating it? I really appreciate your input.

IJWS15 and tall_tone - Many thanks for clarifying my understanding of this

GW

 

[mack4]

This sloop is too steep, planks will not follow the "curve" and end up high above the deepest point of the sloop.

WYL: Can I be cheeky and correct your english?! It is 'slope' not 'sloop'

Well you must be brave, and you are correct the 3mm / 3m referred to is regarding undulations.If, as the OP states the floor is flat, but subject to a 22mm "run" then there should be no problem.I am in no doubt however that Karin will have the last word on this though.
mack

 

[tall_tone]

Sorry, missed the point of the original question. Can you float it?

My thought here would be that the floor will try and work it's way to the lowest point, thus you could end up with no expansion gap at the lowest point and double the expansion gap at the top.

My vote would go with some form of fixing.

Over to you WYL for the final say.
TT

 

[mac391]

Easy now tall tone,, do you really think that a 100 kilos of wood flooring is going to float away to one end of a room that is 2.2 cm lower than the other end, with a sofa, an armchair, coffee table, tv, skirting, expensive chinese rug, fish tank, 3 pairs of slippers, several empty coffee mugs, a henry hoover, 3 tons of junk mail, discarded news of the world and a pair of half eaten edible undies (under sofa).... on it ??

This floor is a typical "british built" slightly uneven and perfectly nomal sub-flloor !!

The (3mm in 3m rule) is the same as (1mm in 1m) or (6mm in 6m) and regards undulation (high and low spots) not floor level.

If anyone can achieve this on concrete with a steel float, you've got a job for life !!

I wonder if the white collar worker who devised this rule can ?

It's been a while since i read BS8201 but unless it's been revised, this rule regards laying plank/block flooring on a concrete sub-floor with trowel spread adhesive!!

Oh yeah, just lay your floor gotwood, it's fine...

 

[WoodYouLike]

This sloop is too steep, planks will not follow the "curve" and end up high above the deepest point of the sloop.

WYL: Can I be cheeky and correct your english?! It is 'slope' not 'sloop'

You can and you must, still learning the Queen's English

Not sure if this counts as the last word Mack, but we have never seen a concrete floor with a gentle slope starting at one straight wall and really flat gradually sloping in one fluent direction to the other wall not causing any problems.
If this is indeed that case in your situation GW then I stand correctly and you can install your wood floor floating or fully bonded - but as soon as the total 22mm slope is not spread gradually over the 3.5 meter you have to level out one way or the other and then your best bet IMHO is to install floating instead of trying to fully bond the floor to the concrete/screed. (With fully bonding 85% of the boards should be in contact with the adhesive - without additional help of weighing the board down that is)

 

[JohnD]

Sloop:

 

[WoodYouLike]

Sloop:

Nah, that's a sloep

 

[GotWood]

You beautiful wonderful magical DIYnot members - you have taken me from the pit of despair to the lush green meadows of potentially-having-a-floor-land. Thank you one and all

Floating is best for sound insulation, right?

 

[WoodYouLike]

Yes (and no - but that's a completely different story we won't go into now - involves test reports etc on design parquet and mosaic subfloors, rare in the UK).
Depending on the type of underfloor (don't think you mentioned this yet, or am I turning blind/old/you name it ) you have which type of underlayment is best for you:
concrete: Timbermate Excel (includes a DPM)
existing floorboards/plywood/chipboard: Timbermate Duractex (without DPM)