floating real wood floor

[wood wizard]

can anyone give me some advice, i am about to lay a real wood floor on concrete (15+ years old).
due to the restricted height i can take the floor level up (approx 25mm) because of the front door i need to keep the make up to a minimum.
my proposal is to lay a dpm (advise on suitable product), lay 4mm ply floating on the dpm and glue the real wood flooring directly on to the ply, i intend to leave a clear 10mm gap the entire way around the room so effectively giving 20mm expansion over 5m.
i need to know which glue would be suitable for this, preferably a quick cure glue due to time restrictions i have.
i also need to know if my proposal sounds sensible or if it's heading for problems later in life.
thanks in advance.

 

[WoodYouLike]

What's the width of the room?
If not wider than 5 - 6 meters you could install the floor floating (using underlayment which includes a DPM) and glue the T&G's.
Or, if the concrete floor is level and of good quality (i.e. not crumbled) you could use Stycobond or Lecol or Mapei parquet adhesive.
Your expansion gap can be calculated as follows: for every meter wide add 3 mm, but with a minimum of 10mm. (e.g 4 meter wide room is 12mm, 3 meter wide room - 10mm)

 

[wood wizard]

the lounge is 5x3.5m and i also intend to floor the hallway 1x4.5m. i don't think i will have any problems achieving room for expansion.
for a dpm i was thinking of a heavy gauge polythene with duct tape to seal any joints, is it going to be suitable?
i live in a first floor flat, i have never seen the condition of the concrete but i anticipate it being of good quality with only very minor level discrepencies. children live in the house so the house is always kept warm with minimal changes to temperature.
really what i need is assurance that glueing the flooring to 4mm ply will be suitable? if not then can you explain why not.
i also need to know what glue would be suitable for above application?
in hindsight i wish i had gone for engineered dry fit boards, to late now though!!!

 

[WoodYouLike]

in hindsight i wish i had gone for engineered dry fit boards, to late now though!!!

I can't see any reasons why you shouldn't install your flooring floating (i.e. placing DPM + sound-insulation first and glueing the T&G's). We do this regular without any problems as long as the wood is good quality, the correct size expansion gaps are left and customers are 'trained' to keep their house climate reasonable.

 

[wood wizard]

will the 4mm ply be a sound insulation?
thank you for your advice, i have seen some very good advice you have been giving out.

 

[WoodYouLike]

Lets get back to basics: how thick is your solid wooden flooring? Is it T&G-ed? If so, there is no need to install plywood (floating) first.
You have either the option of glueing the solid floor directly to the level concrete underfloor or
install a combi underlayment (DPM + 3 - 4 mm sound-insulation) and install the wooden floor floating (glueing the T&G).

Your floating plywood will not act as a proper sound insulation and is IMHO waste of money, time and materials Also not sure where or from who this idea comes from?

 

[wood wizard]

the solid wood flooring is 20mm thick, T+G.
from what you are saying i only need to glue the T+G and not fix this to anything below, the idea of glueing down the wood comes from me, the salesman told me i would have to nail the flooring down to 9mm or greater ply wood, due to restricted height i can actually raise the floor i suggested glueing the boards to 4mm ply, he said this would be a suitable solution.
am i reading what you are saying correctly,
1- clear floor area
2- lay 3 to 4mm dpm
3- lay wooden flooring directly on top glueing only the T+G
4- leave to set
5- enjoy my new floor

where is this dpm available, is it a stock item or will it need to be ordered and also what price can i expect to pay (25m2), is the dpm in sheets or roll?
if only glueing T+G what glue should i be using?
thanks for your advice, certainly alot better than salesman (would be better placed selling hedgehogs).
one last question, do i really require sound insulation?

 

[WoodYouLike]

Hi again

Re number 2: what I meant was: the combi product availalbe has a total thickness 2 -3mm or 3-4mm and includes a DPM layer. Brands available are Timbermate Excell (4mm) or non-brands (ours is 3mm and comes in a roll of 25 sqm) any specialised wooden flooring shop should have them in stock.
Where you can also get bottles of PVAC wood glue (many brands and non-brnad available).

Enjoy your floor.

 

[wood wizard]

Hi again,
Thanks alot for advice, i'm going to look into combi product in more detail.
It is ok to glue only the T+G though? I have visions of it splitting in one joint and then the whole floor coming apart, this vision is based on the fact the salesman told me the flooring would have to be nailed down.

 

[WoodYouLike]

Yes, it's alright to glue (the whole lengths) of T&G, we do this all the time, no splitting or whatever.

 

[wood wizard]

thanks alot for all the advice, i'm going to go with your proposal of dpm and lay flooring floating on top.
how long should i ideally leave this for before walking on it?

 

[WoodYouLike]

Install the first three - four rows, have a tea/coffee break.
Then walk very carefully over the freshly installed boards (if needed) to prevent 'walking them open' while the glue sets even more.

Place (heavy) furniture back the day after.
(Life is simple )

 

[wood wizard]

was just reading a few other topics on here and came across a link to your web page, you certainaly know your stuff and your advice here has been greatly appreciated.
i collect the wood this saturday and its going to be sitting for a week in the house before i lay it, when laid i am planning to be working my way out of the room and therefore should beable to avoid walking on it untill the next day when i have to put new skirtings on and get furniture back in.
i'll get back on line after it's laid to let you know how it went.
have you any advice on trimming my front door to size?
also should i cut round the feet of storage heaters or go to the effort of lifting them and replacing them on the wooden flooring?

 

[WoodYouLike]

have you any advice on trimming my front door to size?
also should i cut round the feet of storage heaters or go to the effort of lifting them and replacing them on the wooden flooring?

Thanks for your kind words, appreciated.

Best (long term) option for your front door is to leave it as it is (if possible) and to lay an entrance mat there: you don't need to cut the (mostly) heavy door and re-fit the all those bits that keep the rain out (don't know the correct word for that, sorry), plus the entrance mat will protect your new wooden floor better. You can install an end-thresholds over the wood where it meets the mat for a neat finish

Storage heaters: depending on the angle of the feet you might try to drill a whole in the board that goes 'around' it. Don't know the situation on site, so I'll leave that one to you.

 

[wood wizard]

one other question before i lay this flooring, should i be using tension straps or some kind of clamp during instalation or will i get away with just chapping the T+G together with rubber/wooden mallet and check each joint is tightly fitted together?