Type of underfloor is type of underlayment

Based on the 'floating' installation method it depends on the type of underfloor you have what kind of underlayment you need for your wooden floor. (Floating means: wooden floorboards not fixed to the underfloor with adhesive or nailed onto joists/on existing floorboards or sheet material, and where the T&G is glued with PVAC wood glue.)

Concrete floors =  DPM plus sound-insulation (DPM stands for Damp Proof Membrane). More and more sold as a 1 in 2 product with handy self-adhesive overlapping strip of DPM. (Blue roll in picture)

The DPM layer prevents any residue moist from the concrete getting into the wood. Not really needed on concrete underfloors on second floors, but it won't hurt.
The attached foam layer acts as an sound-insulation preventing your real wooden floor 'sounding' like a Melamine Laminate floor and has the ability to 'fill' some minor unevenness in the underfloor.

In existing floorboards, plywood or chipboard underfloors DON'T us DPM. This can cause condensation between the DPM and underfloor/wood. When your underfloor is level a 2-3mm foam is sufficient (white roll). If you need more sound-insulation it's best to use a thicker underlay (brown roll in picture, also available with DPM attached to it for concrete floors).

Whatever kind of underlayment you need, don't cheapskate with the materials you use: it'll cost you in the end (inferior materials = more time correcting plus the end result of your natural real wooden floor could sound like a 'plastic' Melamine Laminated floor).

If you have two or more different types of underlayment, read here

Comments

[keith]

Hi There, I bought some Wetsco ( real wood flooring with oak veneer) glueless and it has been acclimatising in the hall i aim to lay it in , the subfloor is concrete and bone dry ( house built 1995 ), i was aiming to use the white foam laminate floor underlay ...Can i use that method if the house is fairly new or do i need to use the DPM ?

panel sizes 1220 x 145 x 13.5 mm

[Wood You Like Ltd]

Hi Keith

On ground floor concrete, no matter how old, young or bone dry now, you should lay an underlayment that contains DPM, the so-called combi-underlayment (DPM + sound-insulation).

To be honest, any laminate floor underlayment is not suitable for your real wood floor.

Hope this helps

Wood You Like Ltd

[keith]

Cheers mate , i had a notion i was pushing my luck and its sooooo good to have expert advice given so quickly ! and no nonsense , i appreciate your devotion to this great site ..well done .

Keith

[lynne saunders]

Could some one help me... i have bought random length oak flooring, some lengths quite short. I wanted to glue the oak to the floor which is chip board, but feel as it is in a conservatory. it may get too hot in there and may lift.So what about a floating floor? Can you tell me which type of underlay i may need. Thanks

[Karin H.]

Hi Lynne

Chipboard can't be glued onto I'm afraid and solid Oak is not really suitable to be installed in conservatories due to the rapid changes in temperatures there.
Also, because of the many short lengths these solid Oak floors are not suitable to be installed floating, the many joints will work as hinges, making your floor very unstable and prone to move.

If possible, replace the Solid Oak random length wood floor for wood-engineered Oak floor which has long lengths and then install the floor floating on foam underlayment (without DPM)

Hope this helps

Wood You Like Ltd

[Juliet Price]

I have a new pitched roof kitchen extension, with velux rooflights and french doors. Although light, it gets almost no direct sun, so no huge temperature swings. There is an insulated concrete slab floor (rough) which the builder wants to raise with joists, adding extra insulation and weyroc boards to reconcile floor levels.I would like to install a solid oak floor, varying lengths. Any advice on DPMs, underlayments, best fixing method, advisability of weyroc?

[Karin H.]

Hi Juliet

The installation of the Solid Oak floor using the floating method depends on the amount of short (very short) lengths of the floor. Many "offers" contain too many short lengths to use this method safely: the too many joints will act as hinges, making your floor unstable.

If this is the case, you should fully bond the floor with flexible adhesive, not sure this can work on weyroc - not if this has a moist repellent surface to which no adhesive will bond. suing thinner wyroc and adding 8 - 12mm plywood would then be the solution.

Hope this helps

Wood You Like Ltd
Karin Hermans

[Julie]

My floor-covering at the moment is ceramic tiles but I would like wooden floorboards. Could they be lain on top of the tiles?

[Karin H.]

Hi Julie

Thank you for your question. Is possible if:

ceramic tiles are even, in overall good nick and firmly stuck down to
the underfloor
your wooden floorboards are suitable to be installed floating
you use an underlayment which contains a DPM
Hope this helps

Kind Regards
Wood You Like Ltd