Q and A's on how to lay a wooden floor 2 - preparations

Our most popular article: "How to lay a wooden floor, keep it simple" has a total of 3 pages of further Q and A's, in our opinion becoming too laborious for everyone to have to go through. We all know every home, every situation, every interior design style and/or wishes are different so no article on its own will ever answer all questions, but we can but try.

In this (and following) article we have grouped Q and A's from the original article per, we think, related subjects.

Preparations:
Q: Lifted old parquet flooring. How can I remove bitumen before laying?

A: With a lot of elbow grease I'm afraid. Chisel off as much as possible and remove last bit with petrol - kerosene (very, very careful with this!!!!)
Any residue of bitumen will effect the bonding time of any modern adhesive type (like Lecol5500 or B92 Stycobond): instead of 4 - 5 hours it can take up to 24 hours before it holds properly and you can sand over it.

Q: Hi there
We've just built a new house and have had the heating on for the past number of weeks. We tested the moisture level of the concrete the flooring will go on at it's currently 4%. The wood for the floor has been in the house for the past 2 weeks.
Would we be ok to go ahead and lay the flooring now?
Thanks Avril

A: Dear Avril
You have to wait a bit longer we're afraid. The moist level in the concrete should be 2% or less before you can install the wood floor.

Rule of thumb: every inch (2.5 cm) of concrete/screed takes approximately 30 days to dry.

Q: In that I am totally inexperienced at this, I humbly engage your patience.
Would I need to remove the old flooring before laying the new or could I do a layover? My house was built in 1911; the panels have not been changed since the origination
Thank you Bobbie

A: Dear Bobby.
If your existing floorboards are level (un-cupped and sound) you can install your new floor on top of it without any problems.
We recommend you use a foam underlayment for sound-insulation, leave expansion gaps all around of min. 10mm.

Hope this helps

Q: Hi,
I'm planning to install 20mm solid oak T&G into my kitchen. The room is 8m x 3m total size, but half is well ventilated suspended (400mm joist spacing), and the other half is concrete (30yrs old, dry).
I want to lay the boards parallel to the shorter wall, to try to give the impression of a wider room.
As luck would have it, the heights of the concrete and joists do actually match, so I don't have any making up to do there, but I'm not sure whether to:

1. Lay directly onto whats there; I would have to noggin all the joists first because they run in the 'wrong' direction. I was going to secret nail to the joists but then when I get to the concrete I suppose I'll have to glue?
2. Counter batten the entire lot and then secret nail the whole lot to these. Unfortunately though this would raise the whole floor by the batten depth (at least 20mm?), and the head height is already 'snuggish' in the concreted half of the room. Also this would give a nice trippable step coming into the room...

I realise I'll have to live with a compromise somewhere though, I just wondered what you would do if it was your place?
Cheers, Tom

A: Hi Tom, welcome
We would make sure there is one type of underfloor, using sheets of hardboard (glued to concrete, nailed to floorboards). This will also solve your problem of installing the new boards in the same direction of the old boards.
Then, depending on your preferences you could either glue the new floor to the hardboard or install floating using a foam underlayment.
Hope this helps.

Q: Hi, I want to lay 23 m2 of solid oak T&G flooring, the existing floor is a concrete one, with hard vinyl tiles layed down on bitumen. what would you recommend? If I take up the vinyl tiles I know it will be a real pain getting up the bitumen, but if i lay the oak floor floating, will I have problems with it coming apart?
lee

A: Hi Lee, welcome

If the vinyl tiles are stuck down well, the underfloor fairly level and your solid Oak boards are wider than 110mm then we would install a floor in this circumstances floating on a combi-underlayment, glueing all T&G's correctly.
Hope this helps

Q: Hi, thanks for the quick response. Unfortunately the floor is a solid oak,18mm thick, by 83mm wide random plank length, so I assume laying it floating is a no-no. would it be possible to glue it to the existing vinyl tiles, provided they were stuck down well?
lee

A: Hi Lee

We're afraid not. The structure of the tiles will not allow the adhesive to bond correctly. alternatively you could screw plywood ontop of it first and then glue the wood floor on to that.

Q: Hi Karin, thank you again. Ive decided to fetch up the existing vinyl tiles. I'm either going to use elastilon strong over a DPM, or use a primer and a liquid batten such as sikabond T2.
Which method would you recommend? And do I have to remove all the bitumen residue from the concrete before using a primer?
Many thanks for your patience!
Lee

A: Hi Lee

The more bitumen you remove the better it is. Using Elastion also has the advantage of tackling minor unevennesses in the underfloor, but for the rest it is personal preference what to use.

Comments

[Martin R]

Hi there,
I'm planning to lay wooden floorboards in our first-floor bedroom, using glue. I have 2 questions:
1) the existing floor is screed over concrete. It's a bit soft and crumbly. I've heard that I should use some kind of product to pre-treat crumbly or dusty floors before applying glue - what do you recommend?
2) when applying glue, do I simply spread it over the floor, or do I apply it to the tongue and groove of the floorboards as well?
Thanks for your help

[Karin H.]

Hi Martin

You do need to prime your screed floor (and your best bet is to ask a builder merchant what brand to use)

As for glueing: spread flexible adhesive out on the floor (not too much at once) and use a notched trowel to create ridges.
No need to apply glue to Tongue and Groove when fully bonding the floor.

Wood You Like Ltd

[Martin R]

Hi Karin,
Thanks very much for answering so quickly! This is the best website on wooden flooring on the Internet!

[Karin H.]

Thank you for your compliment Martin, always nice to know our information is appreciated and considered useful.

Wood You Like Ltd

[ashley hunter]

hi there planning to install a floated solid oak floor on chipboard and screed ,screed is in good condition can this be done with the right underlay

[Karin H.]

Hi Ashley

Do you mean you have to types of underfloors? If so, you should create one type of underfloor first with hardboard or plywood and then use foam underlayment without DPM

Hope this helps
Wood You Like Ltd

At 21:12 02/03/2009, you wrote:

[Dougie]

Hi, Our bungalow has Waterproof fibre board floors (10yrs old) we had solid oak flooring fitted last year over a foam base layer,7 months on the floor has warped and risen and is being replaced by the fitter, No dampness found, can you give me advise as to how the floor should be laid, Glued or floated, should a membrane be fitted

Thanks Dougie

[Wood You Like Ltd]

When the floor was originally installed, what method was used and how wide were the expansion gaps left by the fitter?
Also, had the wood floor been given time to acclimatise to its new surroundings? If you could tell us that, we can advice you better on this.

Wood You Like Ltd

[Dougie]

Hi The expansion gaps were 1cm all round and slightly larger in places all hidden by the skirting board, the floor has expanded in places over 2inches, the floor was acclimatised for 3-4 days before fitting? It is also a suspended floor not nailed or glued.

Thanks

Dougie

[Wood You Like Ltd]

Hi again

1cm should have been enough IF your room is 2.5 meter wide (with solid Oak floors). Solid wood needs more days to acclimatise normally, especially when you do not know how or where the floor was stored before.

If the same floor is now being refitted it will have had plenty of chance to adjust to your house climate. Use foam underlayment (without DPM), glue the T&G correctly and make sure the expansion gaps are wide enough.
Rule of thumb for Solid Oak floors: 3 - 4 mm per meter width of the room (so 3 meter wide room means between 10 - 12mm gap)

Hope this helps
Wood You Like Ltd

[Dougie]

Thanks very much for you advice, I am going to give the new wood 2 weeks to adjust to the house climate and then will make sure the correct gaps are used re your advice.

Thanks

Dougie

[L Burke]

I have a new house of 3 years old with concrete floor & looking to put ina solid wooden floor.Have been given differnt advice- Advised taht either glue it down or use plywood & nail it - what is the best option & would plywood be laid & then the oak just nailed ontop of it?

[Karin H.]

Hi L Burke

And then there is the floating option too. As long as your concrete floor
is sound, level and dry all 3 options are possible.
For more details and what to be aware of when installing Solid boards:
Solid Floors - what to note

Hope this helps
Wood You Like Ltd