Underlayment - vinyl and wood laminate flooring

[JohnBishop]

Hi,

What would be your recommendation for underlayment in these two scenarios:

1. 1st floor standard wooden decking - wood laminate flooring and vinyl flooring in the bathroom

2. ground floor concrete base - vinyl flooring (kitchen) and wood laminate flooring

 

I also have to work out what to use for the hallway and stairs I reckon vinyl would be a better option

 

Thanks

Edited June 9, 2022 by JohnBishop

[JohnBishop]

I think I go for wood laminate flooring and decent vinyl in the kitchen and perhaps bathroom. I see most laminate is 8mm thick, I can see some premium 12mm like Tegola.

 

What do you think about this 3mm underlay for laminate or vinyl flooring? I reckon on wooden decking is OK, what about ground floor concrete? Is this safe to put and not get some weird moisture etc?
https://www.carpetright.co.uk/underlay/timbershield-wood-and-laminate-underlay-3mm/

 

Or do you know any better option?

 

Edited July 21, 2022 by JohnBishop

[Conor]

We used 5mm Wood fibre underlay for our laminate, and 2mm foam rolls for the LVT. For our roll out vinyl we didn't use anything. All screed floors tho.

[markc]

The 5mm wood fibre underlay is fantastic under laminate 

[JohnBishop]

can I use this 5mm wood fibre underlay directly onto the concrete? or should I put something else underneath it?

 

By the way what thickness you go for? 8mm? I think 12mm is a bit overkill with the 5mm underlay.
Let me know when you shop them as I am confused and can easily can get ripped of.

Edited July 21, 2022 by JohnBishop

[markc]

8 minutes ago, JohnBishop said:

can I use this 5mm wood fibre underlay directly onto the concrete? or should I put something else underneath it?

Assuming your concrete floor is dry (DPM underneath) then the wood fibre is fine straight on top. If it’s an old concrete floor with no DPM under then I would use a underlay with membrane.

[JohnBishop]

12 hours ago, markc said:

Assuming your concrete floor is dry (DPM underneath) then the wood fibre is fine straight on top. If it’s an old concrete floor with no DPM under then I would use a underlay with membrane.

This is a 90 yrs old building. Not sure how old is the concrete but I reckon DPM is not there. Not sure if there is a way of checking this.

[markc]

8 hours ago, JohnBishop said:

This is a 90 yrs old building. Not sure how old is the concrete but I reckon DPM is not there. Not sure if there is a way of checking this.

Morning, definitely won’t be a DPM (other than maybe a bit a tar or pitch) and definitely no insulation.

you need a membrane on top of concrete or a water proof underlay to stop water being drawn up into the underlay or flooring.

[JohnBishop]

On 22/07/2022 at 07:11, markc said:

Morning, definitely won’t be a DPM (other than maybe a bit a tar or pitch) and definitely no insulation.

you need a membrane on top of concrete or a water proof underlay to stop water being drawn up into the underlay or flooring.

Is there any way of finding this out? This property was managed by the housing association so you would think they have modernised it at some point if they ever modernise these. I don't know.

I have looked into the utility hole where the water and gas pipes emerge but I don't see anything because it looks like ceramic ducting but there is some plastic sticking out, not sure if this is to isolate the ducting or the concrete.

 

Edited July 24, 2022 by JohnBishop

[JohnBishop]

apologies I wasn't clear enough. I meant to find out if they put a plastic membrane under the concrete. I reckon to find out I would need to drill or destroy some of the floor.

Does it mean regardless if the membrane is there or not should I put plastic membrane on top? like this one?
https://www.wickes.co.uk/NDC-1000-Gauge-Black-Damp-Proof-Membrane-4X12-5m/p/152859

and then these wood fibre boards?

https://www.screwfix.com/p/diall-wood-fibre-underlay-boards-7m-15-pack/7824r

this would only be 5mm thick but no insulation value

 

or is it better to use

https://www.carpetright.co.uk/underlay/timbershield-wood-and-laminate-underlay-3mm/

with underlay tape  https://www.wickes.co.uk/Arbiton-Underlay-Foil-Tape---50mm-x-50m/p/220459

with wood fibre underlay on top, this would be 8mm thick in total

 

I checked the doors and on the ground floor there is at least 18mm clearance in the dining doom and between 25 and 30mm in the living room.
Upstairs it is at least 22mm clearance but I put the wood fibre underlay boards only.

 

I aim for 8mm thick laminate boards so I need at least 16mm without cutting the need of cutting doors.

Edited July 31, 2022 by JohnBishop

[JohnBishop]

I am still looking for the right underlayment to put on the concrete.

I have 32mm gap between the concrete floor and doors. and 25mm in the other room (both concrete).

 

I reckon there is a DPM under the concrete as the humidity at ground level hasn't changed, it's stays at 50% but anyway most of these underlayment comes with DPM anyway.

 

I was looking into this:

3mm

https://www.factory-direct-flooring.co.uk/pro-gold-underlay-vapour-barrier

 

5mm Sonic Gold

https://www.amazon.co.uk/Royale-Comfort-Underlay-Laminate-Flooring/dp/B00EZMY36G/ref=sr_1_5?keywords=sonic+gold+underlay&qid=1665958023&qu=eyJxc2MiOiIzLjg1IiwicXNhIjoiMy4wOSIsInFzcCI6IjMuMDAifQ%3D%3D&sprefix=sonic+gold+un%2Caps%2C94&sr=8-5

 

6mm

https://www.amazon.co.uk/Underlay-Thermal-Insulation-Underfloor-Heating/dp/B07HPD2TBB/ref=sr_1_4?keywords=insulating%2Bunderlay&qid=1665956825&qu=eyJxc2MiOiIzLjkxIiwicXNhIjoiMi45OCIsInFzcCI6IjAuOTIifQ%3D%3D&s=diy&sprefix=insulating%2Bunder%2Cdiy%2C74&sr=1-4&th=1

 

10mm (I reckon this is only for the carpet not laminate)

https://www.amazon.co.uk/10mm-Thick-Insulation-Carpet-Underlay/dp/B00EZMXOWK/ref=sr_1_20?keywords=insulating+underlay&qid=1665956825&qu=eyJxc2MiOiIzLjkxIiwicXNhIjoiMi45OCIsInFzcCI6IjAuOTIifQ%3D%3D&s=diy&sprefix=insulating+under%2Cdiy%2C74&sr=1-20

 

I reckon there is no thicker underlayment for laminate than 5mm.
Sonic Gold has very good reviews.

 

I reckon I don't need wood fibre boards for this just the sonic gold.

Please let me know if there are any better options or if I am on the right track.

I am back as I want to do the downstairs and have to decide on the underlayment I put on the concrete.

Edited October 16, 2022 by JohnBishop

[Nickfromwales]

Basing my comments of your sub floor being very flat and level, if not you should use a self levelling compound to get this to a decent enough standard.

Then, for the areas with laminate;

If it were me, I’d go for the XPS as your moisture barrier, and would take no chances there in assuming the floor already has one. The moisture levels would be very different when the surface is no longer exposed to atmosphere so going by that isn’t a very good yardstick afaic.

Then, go for the 10mm fibre for additional heat insulation. You buy insulation once, so invest now, save on heating bills long-term.

For the areas with LVT;

You’ll need a liquid damp barrier, and then to make this up to the required depth ( height ) with a self levelling compound. The LVT needs something under it that can withstand point load / impact, and none of the products you’ve linked are suitable for those areas. If you can buy the LVT which comes on a backer, so it’s like planks, then go for the thicker XPS so you’re insulated and moisture barrier protected.

 

Remember with the XPS to tape the joints with a suitable tape to maintain the barrier. 

[JohnBishop]

Let's say there is a moisture barrier under the concrete already. Isn't that detrimental to the concrete floor if you put another? I mean then it is expected for moisture to collect in between the barriers.

I am going to tape a bigger sheet of DPM to the concrete with a temp and humidity sensor under to see if there is any variation.

 

I think I put a black DPM then the XPS. I read that 1 inch of XPS is considered to be vapor semi-permeable, while 2 inches is considered to be vapor semi-impermeable.

 

What XPS should I go for? How thick 6 or 10mm?
 

What 10mm fibre should I use?

 https://flooringwarehousedirect.co.uk/product/qa-breathe-natural-fibre-10mm-underlay-15m2-roll/

but I reckon I still need to put 5mm Fibreboard Laminate boards on top as the laminate click is likely to disengage on softer underlay.

[JohnBishop]

What XPS should I go for?
I am having difficulty finding it. I need it for about 30sqm.

I found this:
https://www.amazon.co.uk/Foam-Insulation-Boards-1200-10mm/dp/B07X3LWJS2/ref=sr_1_8?crid=XVH0B83U7ZDG&keywords=xps+foam&qid=1668442671&sprefix=xps+foam%2Caps%2C96&sr=8-8

Is this any good?
Should I use anything with the silver thermal reflecting foil?

 

I also order this 10mm laminate:
https://flooringwarehousedirect.co.uk/product/qa-breathe-natural-fibre-10mm-underlay-15m2-roll/

 

I put a DPM barrier on the concrete floor as I have it already.

I unscrew the wide skirting boards and attach the DPM to the wall then screw the boards back.

[JohnBishop]

On 21/07/2022 at 10:39, markc said:

Assuming your concrete floor is dry (DPM underneath) then the wood fibre is fine straight on top. If it’s an old concrete floor with no DPM under then I would use a underlay with membrane.

 

I just removed the skirting boards.

Does it look like DPM to you?
Do you think if I put another DPN on top is this going to be detrimental to what's below?

 

[Ferdinand]

On 21/07/2022 at 22:44, JohnBishop said:

This is a 90 yrs old building. Not sure how old is the concrete but I reckon DPM is not there. Not sure if there is a way of checking this.

 

There are procedures for testing your concrete for damp - most involve drilling a small hole.

As a crude check, tape come polythene to the floor and see if any moisture emerges underneath it in a day or two.

 

(Shoot me down if this is wrong, guys).

 

On you floor build up, I would seriously consider trimming your doors to get a but more insulation in - even 15mm of celotex will make a difference as the first layer of insulation has the most benefit. Is there s thicker version of those underlay tiles? Document whatever you do so that you can make your EPC assessor acknowledge it.

 

On underlay, have a look at the roll products from manufacturers, as these sometimes contain adhesive strips along the sides which stick together - though those under-tiles also look OK.

 

I think I used this one from QuickStep.

https://www.quick-step.co.uk/en-gb/accessories/qsudlbp15_basic-plus-15-m2

 

F

[markc]

Morning, looks like someone layed a dpm and insulation before the slab so all good. No need for another dpm, depending on height available you could lay something cheap foam underlay under the wood fibre, this allows a couple of mm of air space between concrete and wood fibre board.

Edited November 30, 2022 by markc

[JohnBishop]

13 hours ago, Ferdinand said:

 

There are procedures for testing your concrete for damp - most involve drilling a small hole.

As a crude check, tape come polythene to the floor and see if any moisture emerges underneath it in a day or two.

 

(Shoot me down if this is wrong, guys).

 

On you floor build up, I would seriously consider trimming your doors to get a but more insulation in - even 15mm of celotex will make a difference as the first layer of insulation has the most benefit. Is there s thicker version of those underlay tiles? Document whatever you do so that you can make your EPC assessor acknowledge it.

 

On underlay, have a look at the roll products from manufacturers, as these sometimes contain adhesive strips along the sides which stick together - though those under-tiles also look OK.

 

I think I used this one from QuickStep.

https://www.quick-step.co.uk/en-gb/accessories/qsudlbp15_basic-plus-15-m2

 

F

Ok, I have checked the moisture under polythene some time ago and there is no condensation so the original DPM seems to work. I also don't see any humidity fluctuations in the room in the summer or in autumn.

 

Most sell min 25mm Celotex but I found this 15mm one:
https://insulationgo.co.uk/15mm-xtratherm-pir-wall-insulation-rigid-foam-celotex-thermal-board-foil-faced-12mm-celotex-tb4000/

 

Does it mean Celotex goes first, all tight and taped in between and then the Basic Plus underlay on top? No fibre underlay just laminate on top?

[JohnBishop]

13 hours ago, markc said:

Morning, looks like someone layed a dpm and insulation before the slab so all good. No need for another dpm, depending on height available you could lay something cheap foam underlay under the wood fibre, this allows a couple of mm of air space between concrete and wood fibre board.

Do you mean some cheap XPS foam, all taped together then 5mm wood fibre and laminate? Would you recommend anyone in particular or is it does not really matter? I have searched for some but only found a more decent selection on Amazon which I try to avoid.

I have 25-32mm space before I have to cut the doors but the problem becomes the PVC front doors in the little landing that I won't be able to cut.

Edited November 30, 2022 by JohnBishop

[markc]

Hi, yes cheap xps foam underlay material, works great as a moisture barrier under wood fibre sheets.

[JohnBishop]

I decided to put 25mm Celotex on the floor.
Does £187 for 11x Celotex TB4025 Insulation Board 25mm x 1200mm x 2400mm + £60 shipping sounds reasonable?
I need to cover about 28sqm.

 

Do I still need to put this QuickStep underlayment?

https://www.quick-step.co.uk/en-gb/accessories/qsudlbp15_basic-plus-15-m2#Documents

 

By the way should Celotex go against the wall (no gap) or can it go next to the skirting?

Edited December 6, 2022 by JohnBishop

[JohnBishop]

I checked on another thread and it looks like in my case Celotex is not a good idea.
Someone said that 30mm Celotex is the minimum so together with a required plywood, fibreboard and laminate would end up to 83mm.
I don't have enough space under the front door so I cannot put it in there. This would require too many modifications.
I think I just use QuickStep or Multifoil and put laminate on top.