Laying laminates, expansion slot question

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Tomresearch

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#312329 7-Apr-2024 10:55

Hi,

We are laying down laminate flooring, and according to the instruction manual, we are meant to leave about 12mm expansion gap all around. We have removed the skirting boards (which are 12mm wide). We also will use edge trims between laminate and carpets, and between laminate and sliding door frames which are metal, so we cant undercut.

Now, since laminate will shrink and expand with the weather/humidity, how do I know what state the laminate is currently in? i.e. is it fully expanded or fully shrunk or somewhere in between?

If I don't tuck the laminate deep enough under the skirting or edge trims, when it shrinks, I might suddenly have gaps around the edges.

If I lay it too deep, when it expands, the laminate may rise in places.

Hope you can see my dilemma - and can recommend a solution please?

Thank you

Bung

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#3215276 7-Apr-2024 11:53

How big is the room? The required gap depends on the floor dimensions. Some instruuctions give the gap in mm/m or say smaller rooms 6mm, larger rooms 10-12mm. Your instructions could be to cover the case of a large open plan room that isn’t what you have.

tweake

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#3215281 7-Apr-2024 12:34

Let the planks acclimatize for 48 hours in the unopened packaging at the normal room temperature, in the middle of the room where
the floor is to be installed. The ideal conditions are 15-22°C at a relative humidity of 30-75%. If climate conditions are outside this
30-75% range, we strongly advise to acclimatize for 1 week with opened packages. https://www.flooringxtra.co.nz/content/pdfs/QuickStep_installation_Instructions.pdf

odds are its based around 20c 50% humidity. the problem is nz houses are all over the show. also make sure the floor is dry, especially new concrete which will need a lot of time to dry out (and to test). if its on wooden floor then having moisture barrier under the house will help a lot.

Tomresearch

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#3215319 7-Apr-2024 17:06

Hi @Bung,

Thank you for taking the time to reply. I have included the rough sketch of the area I am laminating

I am laminating the lounge, dining and hall & passage (in the diagram), and all measurements are in meters.

Between the lounge and hallway, I am adding a trim/transition/edge.

What do you think of the expansion gaps for this layout?

Thanks

Tomresearch

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#3215320 7-Apr-2024 17:11

Hi Tweake,

Thank you for the reply, and the link to the install manual.

Cheers

PS. I'm doing all the prep myself - so the laminates have already been in their respective rooms for over a week, and will sit for another week, before the next weekend, when I can start laying the laminates down. Which also gives plenty of time for concrete to set (in a few places I had to grind the high spots, and fill in the low spots).

tweake

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#3215327 7-Apr-2024 17:34

Tomresearch:

Hi Tweake,

Thank you for the reply, and the link to the install manual.

Cheers

PS. I'm doing all the prep myself - so the laminates have already been in their respective rooms for over a week, and will sit for another week, before the next weekend, when I can start laying the laminates down. Which also gives plenty of time for concrete to set (in a few places I had to grind the high spots, and fill in the low spots).

if its new concrete then do the bag test. put plastic sheet over the floor (ie rubbish bag) and tape it to the floor. leave it overnight and see if there is condensation in the bag. i cannot remember how long your meant to leave new concrete. its quite awhile.

there was a case many years ago where a tradie put some expensive flooring down and 6 months later its all bowed/cupped. the floor supplier denied warranty due to being install problem and tradie did a runner. they simply had put the floor down to soon. nz semi damp, unheated houses don't help that.

Tomresearch

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#3215332 7-Apr-2024 18:25

Thank you @tweake, will most certainly try that.

The concrete will be left for 1 week to harden, and its under 3 mm - i first used the Cemix self leveling compound, then in other places the Sika Self leveling compound (Sikafloor level-15).