engineered oak

[chirpychippy]

I am about to embark on laying an engineered oak floor throughout my house. The flooring is from howdens and is a click system, although there is nothing on the instructions regarding my question, I am going to ask it for piece of mind. My sub floor is timber joists with floor boards "circa" 1890 amazingly the floor is still level. Do you think it would be fortuitous to put down a dpm prior to laying or do you think it would be a waste of money, and before you ask the air bricks are not blocked up?

Thank you

 

[mac391]

woodyoulike is an expert on airbricks, i would ask her advice before proceeding..
But no, don't install a DPM. The airflow beneath your subfloor lets moisture escape but some will pass through your floorboards. By using a DPM that moisture will be trapped and will eventually affect your subfloor.
Use a standard underlay for a floating floor,which yours is.

p.s Howdens don't even know what a wear layer is, i suspect yours to be 2.5mm (very thin), i could be wrong but generally their flooring is cheap and sometimes nasty. You get what you pay for !!

 

[audievo]

Can't agree with any of that....sorry!
Howdens engineered although not top quality is not too bad, i also think it is a 14mm engineered board with a 3.5mm wear layer (pretty much standard.)

Also i would say yes to a dpm on an old house with airspace below the subfloor.
The air below the floor will often be very cold and damp, the dpm will protect your new floor from the damp air below.

 

[woodfloordesigns]

I don't know the flooring but presume its standard type. I would go with the dpm. either built into the underlay, something like ball and youngs woodlay or a sheet of 2000 gauge dpm polythene. The underlays the easiest bet.

 

[mac391]

Audivo, you don't have to agree with the info i have given here, but all you have achieved is to confuse the original post. You shouldn't disagree with anyone's comments unless you are absolutley 100% sure you know what you're on about. And it is apparant you don't.
The advice i have given is 100% correct, a standard underlay on suspended floors, without a dpm should always be used.

As for Mr "woodfloordesigns" i'm sure your still learning, just havn't quite grasped this point yet !! Do some research then be kind enough to let us all know your findings..

To confirm.... A DPM on a suspended timer floor will trap moisture that will collect in or on your joists and subfloor, eventually causing decay. Use a standard underlay with no DPM that will allow moisture to excape slowly but surely, "without affecting your new engineered floor covering".

 

[woodfloordesigns]

Isn't it odd that mac391 can only make a point by insulting others, me ,audiveo, howdens. Still, perhaps he's a God

 

[WoodYouLike]

To confirm.... A DPM on a suspended timer floor will trap moisture that will collect in or on your joists and subfloor, eventually causing decay. Use a standard underlay with no DPM that will allow moisture to excape slowly but surely, "without affecting your new engineered floor covering".

I second this.

 

[audievo]

I am 100% sure that you need a dpm to stop cold damp air comming into contacy with the back of the flooring through gaps in the old floorboards.
Idealy "On ground floors a surface moisture inhibitor such as a DPM Underlay or 1000g Visqueen
must be laid with joints over lapped by 6” (150mm) or more and lapped up the wall behind the skirting board." however as this would mean lifting all the boards then relaying the best option is to lay a dpm undelay directly under the engineered floor.
It is now the same for engineered and laminate flooring, if you would like to check please feel free to look on the quick-step website fitting instructions.
BTW i am a quick-step retailer (among many other flooring brands) and have been selling and fitting flooring to thousands of customers for many years, thankyou

 

[audievo]

http://parquet.quick-step.com/media/downloads/installation/Multifit/en.pdf



as you can see quick-step only recomend a dpm underfloor system for their engineered wood flooring

 

[WoodYouLike]

Ahum.

From the download:
"Existing plank floor or sheeting or sub-parquet
First remove the existing fl oor covering above the plank floor. The planks must be fi rmly anchored and fl at. In addition, there
must be no signs of mould and/or insect infestations. The new plank fl oor must be laid in the opposite direction to the old
plank fl oor. The wood must have a humidity level of between 8 and 10%. Any crawl-space under the fl oor must be suffi ciently
ventilated. Remove any obstacles and make sure there is suffi cient ventilation (= minimum 4 cm2 total ventilation openings
per m2 of fl oor)."

Where oh where does quick-step mention to install a DPM when you lay a new floor onto existing floorboards or sheeting or sub-[parquet?

Like we say: no DPM when you install over joists, over existing floorboards, sheet material and existing parquet floors. You'll cause problems in the long run.

 

[audievo]

http://www.quick-step.com/europe/uk/en/faq/0012.aspx


To avoid problems caused by rising damp, you must always lay a plastic foil. If you choose a Quick-Step® underlay, the correct moisture barrier is already attached to the underlay

 

[WoodYouLike]

don't take me wrong, but that page is missing essential information.

DPM on concrete floors (and when there are still vinyl or Marley tiles stuck down) will prevent moist problems, DPM on other sub or underfloors will cause problems in the long run.

Quick-step wants to sell and protect their product and they do not care about what the client is left with in the end.

 

[audievo]

The thing is imo, i think the problems would be worse if you have cold damp air in contact with your flooring as it could have an immediate effect on your new floor.

Are the problems with dpm over floorboards a big problem?
If so then how about all of the millions of m2 of vinyl flooring fitted on ply over florboards, altro, karndene, polyfloor etc?

So ground floor with a designer vinyl floor would be, screwed down ply, feather edge then full stick of vinyl over the ply.
Where can your floorboards breathe now?
How about the likes of tredaire boardwalk of timbermate xl? are you saying these are not suitable for groundfloor installs on floorboards?

 

[WoodYouLike]

The problem is with the DPM closing off the normal air circulation, causing the cold damp air to condensate on the DPM, causing moist problems on the existing floorboards with the risk to also affect the joists.
If cold damp air comes in contact with a normal underlayment (one without DPM) the circulation is still there, no condensation will occur, no long term problems caused.
Vinyl floors etc are constructed to cater for this (they do not close off the ventilation as much as a DPM sheet does).

Timbermate Excel has indeed a DPM in it and should not be used on floorboards. For this you use Timbermate Duratex.

 

[WoodYouLike]

Oh also balterio now

http://www.balterio.com/subfloor.php?lang=en&con=eu

see note at the bottom

"Note: Balterio recommends to use a dampscreen in any situation."

Then do what Balterio tells you to do - I wouldn't.

Once again: there are manufacturers out there who are more interested in protecting their own product than giving the public true and honest information.