Underlay for laminate flooring.

Mach Two

I have 6 mm laminate flooring and need to lay it. It clicks together and is approximately 7.5 inches wide. I have two types of underlay. One with gold coloured foil on it and approximately 5 mm thick and the other is just 2 mm white foam with no foil. It is being laid on concrete. The area involved is approximately 6' by 6'.

Which underlay should I use?

Stoner

What's the question?

Outkast_IRE

Stoner wrote: »

What's the question?

The white foam one is a heap of s**te do not use it. Use the gold one

This may sound silly, but i never realised there was a choice of underlay. i thought the 2mm stuff was all there was.

Does 5mm not leave a bit of 'bounce' in the floor (in a bad way, i mean).

bloodless_coup

[Deleted User] wrote: »

This may sound silly, but i never realised there was a choice of underlay. i thought the 2mm stuff was all there was.

Does 5mm not leave a bit of 'bounce' in the floor (in a bad way, i mean).

No, assuming the laminate is thick enough.

g1983d

Mach Two wrote: »

I have 6 mm laminate flooring and need to lay it. It clicks together and is approximately 7.5 inches wide. I have two types of underlay. One with gold coloured foil on it and approximately 5 mm thick and the other is just 2 mm white foam with no foil. It is being laid on concrete. The area involved is approximately 6' by 6'.

Which underlay should I use?

Do you have underfloor heating? If so you need underlay with a low tog value, other than that the one with the foil back

Outkast_IRE

Deleted User wrote: »

This may sound silly, but i never realised there was a choice of underlay. i thought the 2mm stuff was all there was.

Does 5mm not leave a bit of 'bounce' in the floor (in a bad way, i mean).

Your first mistake was going with a 6mm board.

I would consider 10mm the or 12mm the thicknesses i would use in my own house, as when layed on good insulation they feel solid.

With a 6mm board i find if they are layed on the white 2mm foam it can sound hollow and light underfoot.

Mach Two

Outkast_IRE wrote: »

Your first mistake was going with a 6mm board.

I would consider 10mm the or 12mm the thicknesses i would use in my own house, as when layed on good insulation they feel solid.

With a 6mm board i find if they are layed on the white 2mm foam it can sound hollow and light underfoot.

The 6mm flooring was for another job. I am putting it in a small room 8' by 6'. It is a home office so I expect very little traffic on it. If I use the 5 mm underlay under the 6 mm laminate flooring would there be so much give in it so as to pull apart the flooring when it's being walked on. Personally I don't think there will be.

Outkast_IRE

Mach Two wrote: »

The 6mm flooring was for another job. I am putting it in a small room 8' by 6'. It is a home office so I expect very little traffic on it. If I use the 5 mm underlay under the 6 mm laminate flooring would there be so much give in it so as to pull apart the flooring when it's being walked on. Personally I don't think there will be.

I don't think it will be an issue the foam is very dense in the gold underlay and doesn't give as much as you might think.

listermint

For underfloor heating - low tog value.

Most people do not have underfloor heating so does not apply.

For Most people, go with the thickest underlay you can get

Why ?

Because it adds insulation 'warmth' to the room.
Removes that crappy bounce effect.
Makes the floor feel solid underfoot and stops terrible crappy echoey noises.


Try in vain to steer clear of any of that thin foam crap. and if you can get fibre board. There are drawbacks like having to possible adjust Kickboards and skirting or the Saddleboards. But Fibreboard would be top of the list ideally.

tenbob1

5mm underlay can and does cause too much "bounce" on the flooring, this can lead to the click system breaking after a number of months. Density of the underlay is more important than the thickness. Get a high grade 3mm PU underlay if you can, it rates much better than the fiberboard.

Mach Two

tenbob1 wrote: »

5mm underlay can and does cause too much "bounce" on the flooring, this can lead to the click system breaking after a number of months. Density of the underlay is more important than the thickness. Get a high grade 3mm PU underlay if you can, it rates much better than the fiberboard.

The gold underlay does seem very dense. I put a small plank of it on the gold underlay and there is very little give in it. Do I tape the underlay together.

I forgot to mention that there is no underfloor heating. I did put it in the kitchen though and it seems to be a great success. I am using a stove to charge it at night and the kitchen feels very warm all day. Almost too warm. Very little cold weather yet so maybe not a real test yet.

listermint

tenbob1 wrote: »

5mm underlay can and does cause too much "bounce" on the flooring, this can lead to the click system breaking after a number of months. Density of the underlay is more important than the thickness. Get a high grade 3mm PU underlay if you can, it rates much better than the fiberboard.

In what respects ???

3mm PU is rubbish, especially rubbish in higher traffic areas.

dodzy

listermint wrote: »

In what respects ???

3mm PU is rubbish, especially rubbish in higher traffic areas.

It's not going to make a blind bit of difference to the OP based on it's intended location / usage.

listermint

dodzy wrote: »

It's not going to make a blind bit of difference to the OP based on it's intended location / usage.

3mm PU versus a fibreboard.

Sorry but the person i asked the question to said it was better rated, better rated for what?

The OP is laying on concrete ,

Fibreboard has much better properties for this purpose than any 3mm PU.

tenbob1

listermint wrote: »

In what respects ???

3mm PU is rubbish, especially rubbish in higher traffic areas.

Ok, just for clarity on this, I am not a DIY'er I deal with this sort of stuff on a daily basis. We do not make broad sweeping statement about products, every one is treated on its own merits. For comparison what I am comparing here is two of the products we stock. Both are excellent products, and we would sell lots of both.

Fiberboard, 5.5mm, 0.11K-m2/W (this is the figure we use to measure heat transfers), TOG 1.1. 18 DB rating (what we use to measure the sound reduction ratings)

3mm PU, 3mm, 0.02K-m2/W (better than the fiberboard.) TOG 1.01 (Worse than fiberboard), DB rating 23DB (better than the fiberboard).

It should also be noted that of all the underlays the fiberboard reacts the worst to moisture, I do not have the RH requirements to hand, but I can get them if you need it.

2mm/3mm foam products are fine if you are buying a cheap floor such as described in the OP, its getting rarer though, most people now especially in new builds are looking for products suitable for underfloor heating, looking for low heat transfer rates, so we would go through a process of finding the correct underlay for each job.

Also "most" PU underlays are crap, not all.

~tb

Mach Two

Does that mean I should use the underlay with the gold foil. It is 5 mm thick.

tenbob1

Is there any label on the underlay you have ? The vast majority of 5mm foil underlay's are causing floor failures, we recommend that 5mm underlay has a minimum density of 53 kgs per cubic metre.

If that information is not on the label let me how that name on the underlay and I will check for you when I have some time.

Mach Two

There is no name or any writing of any sort that I can see. It is left over from another job that I had done. The foam is dark grey almost black in colour.

tenbob1

I would always err on the side of caution, floor failures are always a pain. I would not use it.

dodzy

Mach Two wrote: »

Does that mean I should use the underlay with the gold foil. It is 5 mm thick.

Use the foam.

Mach Two

I expect it would be a disaster under the legs of a chair.

dodzy

Mach Two wrote: »

I expect it would be a disaster under the legs of a chair.

minktrapper

More pressure on the laminate from the legs of the chair and me sitting on it. Or maybe not.

uck51js9zml2yt

I've used the fibre board in several rooms including the sitting room and never had an issue with it. Purely a non technical view point however.

AVFC.Stephen

I always thought the plastic sheeting (the gold stuff) that's attached to the underlay was for laying on concrete

The 2mm I use upstairs

Pedanticness

Looking for a recommendation for underlay.
Putting down Kronotex Mammut 12mm in a sitting room and dining room of a new build, going straight onto concrete. There is no underfloor heating but the rooms are quite large so worries about acoustics.
Was considering 4mm Gold Plus, the only information I could find on the website was 0.09K-m2/W.

g1983d

Mach Two wrote: »

I have 6 mm laminate flooring and need to lay it. It clicks together and is approximately 7.5 inches wide. I have two types of underlay. One with gold coloured foil on it and approximately 5 mm thick and the other is just 2 mm white foam with no foil. It is being laid on concrete. The area involved is approximately 6' by 6'.

Which underlay should I use?

The one with the foil

wolfyboy555

can anyone recommend a good underlay to use with Mammut plus 10mm boards? Every store I go into has a different opinion. Would this 5mm underlay be sufficient?

https://www.qep-germany.com/produkte/xps/


I don't have underfloor heating and it is a concrete floor in a new build downstairs.