help with wood floors on weyroc

[viv123]

Hi there,

We want to fit solid oak flooring on a weyrock subfloor and we need help figuring some things out. We were hoping you could help us. The wood wewant to install is 18mm thick and comes in planks 150mm wide of variable length. The subfloor is weyroc, and has been fitted on the first floor of a new built. We want to install it over about 37 sq m almost all the upstairs floor area. I have read here old posts saying laying directly over weyroc is not recommended for two reasons (becuase weyrock does not give enough support and becuase boards cannot be mailed into it). Yet others indicate they have fitted solid aok floors over weyroc quite successfully althought they indicate they have floated the boards rather than gluing them onto the weyroc.

The manufacturer of the wood flooring (we bought the wood from luxuryfloorings ( solid oak) indicates tbe wood can be glued onto chipboard but they dont specify if it can be weyroc. When ordering, i indicated i will be laying over weyroc, and I was not informed this was not ; they went ahead and suggested Tovcol MS Start . I found out later that i should be buying the next level of strength, that is, TovCom MS. Anyway luxuryfloorings have run out of this one. So i rang a second supplier to buy the appropriate glue. This second supplier says the TovCol glue is not compatible with the water resistant capabilities of weyroc...hmmm although he is not sure. I have found that Bona Quantum apppears to be compatible. The datasheet says a suitable subflooring is V100 chipboard (i am assuming v100 chipboard = p4 - p7 chipboard= and this includes weyroc?). So apparently tbere is one glue that is compatible to weyroc....

I have two questions : the first one is about compatibility of the glue : Have any of you glued solid oakfloor onto weyroc using ms flexible glue such as Bona Quantum or similar?
In terms of level of support : i understand some of you wont install directly on weyroc due to lack of support and the others have done but flioating but ....Would it make a difference if the weyroc is of a certain thickness? Should i worry? Does the weyroc looses strength if i use glue to adhere the boards? Even if the manufacturer indicates V100 chipboard is a suitable subflooring? Or do i definitively have to lay plywood in order to glue down?
I would appreciate any guidance...i am totally confused

 

[Deleted member 174758]

Forgive me for saying this, but to quote the manufacturer (Egger), "Weyroc Protect is manufactured from type P5 flooring grade chipboard faced with thermosetting resin impregnated kraft paper bonded to both sides of the chipboard. ...". It is also recommended for floating floor installations by the manufacturer.

From a structural point of view it is a complete nonsense to suggest that Weyroc sub-flooring does not provide sufficient support - that's what sub-flooring does, it supports the finished flooring - be it carpet, laminate or engineered wood - as well as the furniture and other loadings. The only way a sub-floor isn't going to be strong enough is if the joists are too far apart which would potentially lead to bowing of the chipboard, but that isn't something you see very often.The problem may be floors not being laid flat (because the joists aren't level or they are too far apart), in which case a thin skin of plywood will often sort things out. Chipboard (including Weyroc) will take nails, but plywood does hold them better.

I can see why the moisture-proof coatings would affect glue adhesion. The surface of Weyroc is a lot smoother than ordinary chipboard and water runs off it when new. The glue won't affect its' strength, however. I can't say about the type of adhesive to use with it as I've only ever floated engineered flooring onto it, or set it up ready for the carpet fitters

Just to emphasise the point about strength, there's an entire 6-level Victorian office complex that we (re-)floored out with 22mm Weyroc (cross battened over existing Victorian flooring to bring all the buildings level throughout over all 6 upper floor levels) - it's mainly carpeted but there are areas of floated laminate in there as well. I'm still associated with the building and 5 years on we've never had any come back over the strength of the floors, or levels. I'm a carpenter and joiner, so I'm speaking from a structural point of view

 

[viv123]

Thank you so JobandKnock for your clear and straight comment. I come from South America where floors are normally made out of concrete. And had no idea of the structural capabilities of chipboard. The comments i read in previous chats truly made me doubt about the suitability of weyroc. Then, my next step will be to find an adhesive that explicitly indicates it can be used to glue solid wood onto chipboard. And Bona Quantum appears to be suitable. Thanks!

 

[charliegolf]

For what it's worth, I have 75 sqm ish (all my downstairs) in 18mm solid oak. It's all floated on weyroc. The oldest is 20+ years down, including toilet, kitchen and utility. Yes we have had a bit of water damage over the years, but it's still there, and not going anywhere. The first 'tranche' was not glued in the t & g, the rest is.

 

[crazydaze]

Can you 6mm SP101 Ply over the WeyRoc? Simple enough to glue the wood flooring to that.

 

[viv123]

I guess it is an option but not one that we want to take due to extra costs of glue and plywood if we can avoid them...and problems with increase height etc also . Ofcourse one gets what one pays for...i know...Having said that my doubts regarding structural issues have been resolved. And the data sheet explicitly treats weyroc as a compatible subfloor, insofar weyroc is in fact p4-p7 chipboard which appears to be the case. I will post here pics of the install and report of any problems that may surface...hope not too many...fingers crossed

 

[crazydaze]

I guess it is an option but not one that we want to take due to extra costs of glue and plywood if we can avoid them...and problems with increase height etc also . Ofcourse one gets what one pays for...i know...Having said that my doubts regarding structural issues have been resolved. And the data sheet explicitly treats weyroc as a compatible subfloor, insofar weyroc is in fact p4-p7 chipboard which appears to be the case. I will post here pics of the install and report of any problems that may surface...hope not too many...fingers crossed

I’ve worked in flooring for 25 years and never known a wood flooring company or adhesive company say their product can be glued or secret nailed to chip board, always ply so without doing a bit more research for you, I couldn’t comment much further regarding Weyroc and it’s suitability to be directly fitted to.

 

[viv123]

I understand what you are saying crazydaze, but perhaps things are changing due to progress in the development of flexible glues from the chemistry point of view.

Here is one of various sellers who indicates it is possible:
https://www.ambiencehardwoodfloorin...uide/how-to-fit-wood-flooring-onto-chipboard/

And here is the datasheet of Bona Quantum where it is specified chiboard is an acceptable substrate:
https://www.bona.com/globalassets/c...-datasheet-bona-quantum_quantum-t_03_2021.pdf

And here is a guide of the Wood Panels Industries Federation where they state glueing on chipboard to fit floor coverings is recommended and is acceptable practice --provided no water based glue is used, the content of water in glue is low, or the chipboard is sealed (new p5 chipboard is)...please see:

https://wpif.org.uk/PanelGuide section 2.4 : subsection "2.4.5.5 Adhesives"

So, after reading these i am incline to go for it. I hope it works.
I am not a chemist and could not make a sense of almost any of this following article, but in case you do or want to check it out, or know somebody who can make sense of this, i leave here a link to an article describing the actual components and characteristics of glues similar to Bona Quantum:
https://www.scirp.org/journal/paperinformation.aspx?paperid=113642

 

[crazydaze]

I understand what you are saying crazydaze, but perhaps things are changing due to progress in the development of flexible glues from the chemistry point of view.

Here is one of various sellers who indicates it is possible:
https://www.ambiencehardwoodfloorin...uide/how-to-fit-wood-flooring-onto-chipboard/

And here is the datasheet of Bona Quantum where it is specified chiboard is an acceptable substrate:
https://www.bona.com/globalassets/c...-datasheet-bona-quantum_quantum-t_03_2021.pdf

And here is a guide of the Wood Panels Industries Federation where they state glueing on chipboard to fit floor coverings is recommended and is acceptable practice --provided no water based glue is used, the content of water in glue is low, or the chipboard is sealed (new p5 chipboard is)...please see:

https://wpif.org.uk/PanelGuide section 2.4 : subsection "2.4.5.5 Adhesives"

So, after reading these i am incline to go for it. I hope it works.
I am not a chemist and could not make a sense of almost any of this following article, but in case you do or want to check it out, or know somebody who can make sense of this, i leave here a link to an article describing the actual components and characteristics of glues similar to Bona Quantum:
https://www.scirp.org/journal/paperinformation.aspx?paperid=113642

appreciate your thoughts, but the flooring manufacturers say no, and as a flooring professional, I can’t afford to experiment on my customers projects.
It’s my understanding that the latency of the adhesive is one thing, but more importantly, the movement in the solid wood and the strength of the substrate will fail way before an adhesive will let go.

 

[viv123]

Thanks for the advice

 

[SFK]

Silly question slash possible solution.

My new solid oak floor boards are hidden nailed to the joists. (No chip board or any other boarding between the two, no glue).

Can you identify where the joists are and nail though the planks, through the wayroc boards and into the joists?


Ps use osmo to protect wood after laying - but apply thin layers , never ever thick layers
Sfk

 

[viv123]

appreciate your thoughts, but the flooring manufacturers say no, and as a flooring professional, I can’t afford to experiment on my customers projects.
It’s my understanding that the latency of the adhesive is one thing, but more importantly, the movement in the solid wood and the strength of the substrate will fail way before an adhesive will let go.

 

[Deleted member 174758]

Can you identify where the joists are and nail though the planks, through the wayroc boards and into the joists?

But would you be able to get nails long enough? A standard Porta-Nailer is designed for boards from about 16 to 25mm thick. Add 18mm (the thickness of the P5) to the thickness of the flooring and what would you get - 34mm minimum to drive through? I don't think these flooring nailers will drive nails long enough, will they? (the nailers also drive a serrated wedge-shaped flat nail which probably can't be hand nailed)

 

[SFK]

Jobandknock,
Very good point about nail length.
The angle they have to go in to make the hidden will also increase their required length (and power of the gun).
Drop that idea then.
SFK

 

[viv123]

By the way, i read in other forums that an alternative solution is Elastilon...have any of you used it to installed hardwood floors on chipboard? Sounds promising .
https://www.jfjwoodflooring.co.uk/elastilon-underlay