Wooden Floor over concrete

[Daz66]

Sorry if this has been covered before, I wish to lay a wooden floor over the concrete on beam and block floor to my lounge, kitchen, understair cupboard and entrance lobby. In total about 30ms.

I will be removing the skirting, architraves and cutting the door frames to suit a new floor. My questions are these:

1. How do I stick/hold it down, will I need to level the floor.
2. Can I place a border around the edge and if so how.
3. Can an expansion gap be cut under the plaster to form a shadow gap around the edge, leaving off the the skirting.
4. When fitted what type of sealer should be used that will cover the lounge and kitchen, bearing in mind kitchens tend to get wet at times.

I would like to have a go at fitting it myself where possible and don't particularly want to use a cheap clip type system, it would be good if it was solid or a good engineered system. Any ideas on how much per metre square for supply only and where best to buy.

I am sure I will come up with more questions when you guys start asking me some more.

Cheers

 

[Nick82]

I fitted my wooden floor myself on top of concrete, went really well and was surprisingly easy.

The concrete subfloor didn't need levelling as it was already pretty level being a new build house. There were a few little raised bits of concrete which I just chipped off with a chisel. I think generally you can get away with <1mm variances.

The floor is solid 18mm oak which I bought from a privately owned local wood shop place (they do doors and furniture as well) who also sold me Wurth wood floor glue. The glue is really strong and dries like rubber, reasonably easy to apply but can get everywhere so you need to make sure you have some white spirit to hand and quickly wipe up any splashes/drips. I needed 2 tubs of this stuff to do 30m2 which isn't cheap at £90 per tub, I was probably a little over zealous but it was worth it in the end. The glue also partially acts as a moisture barrier.

I finished my flooring off with 3 coats of danish oil followed by 3 coats of clear matt varnish.

 

[tall_tone]

Wurth wood floor glue. The glue is really strong and dries like rubber, reasonably easy to apply but can get everywhere so you need to make sure you have some white spirit to hand and quickly wipe up any splashes/drips. I needed 2 tubs of this stuff to do 30m2 which isn't cheap at £90 per tub, I was probably a little over zealous but it was worth it in the end. The glue also partially acts as a moisture barrier.

Wurth is a brand of product and they will make a few different types. Specifically what Nick82 is talking about are Silaines or MS Polymer type adhesives like Wurth MS or Bona R850. Bear in mind although these have some moisture proofing properties, but they should never be used as a DPM and adhesive all in one. Check your moisture level and post back if you would like advice.

1. British standard for the levelness of a floor is +/-3mm per 3meters. Check with your wood manufacturer their requirement.

2. Wood Border? Yes you can place a border, but be very careful about sizes and expansion gaps. Generally this is a design used on block type flooring where load from an expanding area loads a single block or two, doing it with larger planks can cause larger areas of movement. Secondly you require very accurate cutting at the ends so as not to look second rate because you wont want to cover the joint with a T bar.

3.Cutting a rebate into the plaster sounds OK as long as you do no damage to any damp proof courses, and the plaster is not itself damp in any way. When you say leaving off the skirting, do you mean having the wood flooring permanently in the recess in the plaster? if so that will a fairly deep recess, is the plaster deep enough?

4. There has been lots of debate on here about different types of finish. My personal preference is for Bona lacquers like Mega and Traffic in this scenario. Hardwax oil would also be a good option here due to it's wax giving water repellance. Neither option would be wrong.

Find a good quality flooring supply company, preferably someone who specialises in wood.

Cost - The bitterness of poor quality is left long after the sweetness of low cost is forgotten

TT

 

[WoodYouLike]

Cost - The bitterness of poor quality is left long after the sweetness of low cost is forgotten

One of my favourite quotes and oh so true. Also remember that quality products will be you trusted assistant during the works.

I wouldn't opt for solid wood if you also plan to install a wood floor in kitchen (or entrance lobby for that matter), wood-engineered boards are better in these circumstances. Opt for a (pre) oil floor, better wear and tear, longer protection against drips and spillages and easier to repair locally when it does get damaged.
See here for more details about all the floor types around:
Floor types - from Solid to Veneer

The choice of installation method depends on the actual product you buy, many of the wood-engineered boards can be installed floating on a suitable underlayment.
How thick are your skirtingboards? If thick enough, why "damage" the plaster, the needed expansion gap will be covered by your skirtingboard.

Read this too in regards of expansion gaps:
Gaps! They are there for a very good reason!

 

[Nick82]

i have solid oak in my hallway and it is absoloutely fine.

for the expansion gap just leave 10mm all around and you'll be good, unless you are doing a large area, which youre not. I fashioned some wooden pegs 10mm thick from scrap wood to use as spacers around the edge to give me my expansion gap. Majority of skirting boards are a bit thicker and will cover the gap.

 

[WoodYouLike]

Would you mind if I added a little bit more rules of thumbs to your expansion gap notion?
Just 10mm is the absolute minimum you have to keep with any type of wood-flooring, but especially with solid wood. The rule (for Oak) is 3 - 4mm per meter width of the room, so yes, in a hallway you're fine with 10mm but even in a room 3.5 meter wide is easily amounts to needing 14 - 15mm

also, please note this: Keep your wits about widths

 

[Nick82]

All I can go by is my own experience and the 10mm gap all around my 3.5m x 4m living room was more than plenty. Maybe I just got lucky

 

[Daz66]

Thanks for the advice so far it been very helpfull, just need to find some solid oak that reasobably priced. The room itself is about 22m square so its fairly big running 4.3m wide and nearly 5.2 at the longets parts including the lobby. The kitchen is much smaller bit I will run the flooring wall to wall and it may be the same as the lounge or I may go for tiles, not decided yet.

Should the expansion gap be 10mm at each end or 10mm overall? I am hoping to 'hide' this in the plaster with the shadow gap, if not I will have new skirtings to match plus the plaster cut back to accomodate the expansion gap required. Will it only expand over its length or wil it expand in its width as well?

Will the wood need to 'seasoned' to the room before laying and for how long, we will be living in the place so it will be awkward having lengths of wood laying around for a few weeks before fitting. Also should it be T&G or just butted together, I am hoping to get some reclaimed stuff so may have to do some work on it first if necessary.

 

[Nick82]

You will need >=10mm gap all around the perimeter. The wood can expand in all directions although I think it will expand more in one direction than the other.

It's generally a good idea to let your wood acclimatise to your room before laying it. I gave my wood 1 - 2 weeks.

 

[WoodYouLike]

4.3 wide area means you have to keep at least 15mm gap all around (don't forget, also around radiator-pipes, doorways, fireplaces etc). Still not in favour of solid wood flooring if you plan to install it in the kitchen too.

And be aware of the "reasonable" prices solid Oak flooring from many DIY-sheds: 300 - 1200mm long means 9 times out of 10 many very short lengths = many joints, hinges = unstable floor.