solid wood flooring on to bitumen

[goafer]

Hi, just joined this site, can someone advise if I can lay 18mm solid oak flooring onto a concrete floor that is covered/sealed with what I assume is a bitumen product. I have been told by Seka technical department that the bitumen needs to be removed, this seems drastic, and contrary to what others are saying, if this is not the case what is required, the bitumen seems hard to the touch and is pretty well level, would it be better to cover the bitumen with a screed ?, or, just PVA it, then glue the 120mm planks of solid oak?, grateful for as much info/advise as possible, as I am desperate to get it right first time. goafer.

 

[tall_tone]

Personally I would tend to put some faith in a very large specialist flooring adhesives company like Sika to know what they are talking about.

You have 2 options as far as i can see.
1. Mechanically remove the bitumen, (there can be trace amounts only) prime the surface with an epoxy DPM, or 2 coats of epoxy if it is replacing the DPM. Level the floor if need be then stick the wood, ensuring you follow the manufacturers instructions at all stages.

2. Get a contractor in to do it correctly for you.

The hard bitumen is a very brittle surface, and in many cases is also the Damp Proof Membrane for the floor.

Would you like to bet the cost of your floor on the old bitumen not being cracked or broken in any way?

TT

 

[flooringman]

Is it bitumen or is it asphalt?

Bitumen will be a thin, usually soft layer whereas asphalt will be a thicker hard layer and quite brittle.

You need to check what it is before you proceed.

 

[goafer]

Hi and thanks for the replies. I have removed a small length of wood running along one edge of the sealant, this wood covers a gully with pipework in going to a radiator. I have measured the thickness of this sealant which is approx` 15mm thick, it would seem according to what you say to be asphalt and not bitumen as I first thought, if this is the case does it make a big difference, if so to what extent ?. Goafer.

 

[flooringman]

If it is as thick as you say it sounds like asphalt.

It is possible to use an isolating membrane over the asphalt that will allow you to glue down a solid wood floor.

However, there is a possibility that if the wood moves then it can pull the asphalt as the asphalt is not actually bonded to the sub floor.

If the asphalt is level then you can either float an engineered wood floor over it or if you really want a solid wood then I would suggest the use of Elastilon.

 

[goafer]

Thanks for the info, I called in a firm of asphalt suppliers who advised the flooring was covered with Mastic Asphalt, and in their opinion wooden planks could be glued providing it was water based and not petroleum/oil based. Do you have any experience/thoughts on that ?. I looked into the possibility of useing ELASTILON and have to say I think this may well be the answer to my problem !!!. I looked at the video how to use this and was impressed, Keith.

 

[flooringman]

I would ask the adhesive manufacturers if their product will be ok with the asphalt, rather than rely on the word of the asphalt people.

I would not adhere a solid wood floor to asphalt again myself, I would use one of the two methods I mentioned.

 

[goafer]

Hi flooringman, many thanks for your reply, we are now thinking of using ELASTILON as you suggested. As we want to raise the floor level slightly, about 4mm, can we screed/concrete on top of the Mastic/Asphalt, which we now assume must be the DPM, if so what is the minimum thickness we could use ?. thinking of it cracking etc`, Would it then be advisable to lay a polythene moister barrier on top of the screed/concrete before laying the Elastilon, or is this not necessary, either way I assume this would then become what they describe as a floating floor !!. Dont suppose we could use 4mm hardboard instead of screed/concrete ?. Grateful for anything else you might think of that would be helpful, Goafer.

 

[flooringman]

You would not need another dpm over the asphalt.

The thickness of the Elastilon will be approx. 4mm so that should raise your floor level by the required amount.

If you want it raised by an additional 4mm. then you can screed but you would need to check with the manufacturer of the compound you use as they all vary on suitability and depth of use.

I would not use hardboard over the asphalt.

 

[goafer]

Hi to those who replied and anyone who maybe interested in our outcome. Firstly we called UZIN who advised we should degrease the asphalt floor and allow to dry, then using UZIN PE280 PRIMER cover the floor as per manufacturers instructions using a thin lambs wool roller, leaving again as per instructions before covering with UZIN L3 GOLD 2- component smoothing compound, once dry you can then glue planks using UZIN adehsive, or as we have done cover with a polythene barrier, onto which we laid ELASTILON to which the planks are placed and secured by the top film on the Elastilon once the protective cover is removed, see their self explanatory video. We were told the polythene on top of the L3 GOLD is not a requirement, but we had it so we used it. Sounds very complicated, but if you go on both UZIN and ELASTILONs web site you will get all the info required. Im no professional but found it relatively easy going and the finished product looks great. Hope this may be of some help to someone, and thanks in particular to flooringman, for pointing us in the right direction, and who I hope approves of how we have ratified our problem, GOAFER.

 

[flooringman]

Yes I think the Elastilon method was the best way to go but did you degrease, prime and screed the asphalt or just lay dpm on top of the asphalt?

 

[goafer]

hi flooringman, Did exactly as advised, degreased, primed, then screeded the asphalt, in that order, once dry we covered the screeding with a polythene membrane,( which I was advised was not necessary,) then used the ELASTILON to secure the solid oak flooring, refitted the skirting boards, job done. Goafer

 

[flooringman]

If the asphalt was level why did you degrease, prime and screed - I don't quite see the purpose of that?

You would only need to do that if you were sticking down the wood to the concrete, otherwise it's just a waste of time and money sorry.

 

[goafer]

Hi, firstly the aspalt had a couple of low spots, and apparently the only way you can put a screed on is to prime it first to enable the screed to adhere to the ashpalt. It was my intention to use an adhesive to glue the flooring, which is why I primed and screeded the entire floor, however I decided if I ever needed to lift the flooring in the future it would be better to have a floating floor, which is what I have ended up with, having changed my mind mid streem, I think for the better. Trust this answers your question, Goafer.

 

[flooringman]

Yes it does - I think you did the right thing.