Need to lay Solid Wd floor over 3 different sub floors HELP

[scottylowe]

I need to lay a solid wood floor from the front to back of my house.

I have a really complicated situation and various builders friends shops have given me completely different advice. I would love to do this myself as quotes have come in around the £1000 mark.

It is a small Victorian terrace. The front and back room are knocked together and I have recently knocked it through into an extension that has just been built. So it is open plan front to back. The open plan space is about 9.2 meters (length) and 3.1 meters(width) around 32m2.

The floor is split into 3 sections

1. Front -Original Wooden Floorboards
2. Back -Newly laid(1 week ago) floor consisting of 2 inches MOT, 1 inch SAND, DPM, 100mm INSULATION and 3 inches concrete.(this was original quarry tiles on sand from 1886 so I have replaced the floor to try and achieve a more level surface)
3. Extension - Same as Back(i.e new concrete floor) but with screed on top.

The floors are pretty level.

I wanted to know what you guys thought?
1. Should I nail the floor to section 1? and glue to section 2 and 3?
2. Do I need to use any underlay or DPM on section 2 and 3 (they already have a DPM as they are new floors?)
3. I have been recommended SIKA glue? is it worth it?
4. Some people suggested ply-wooding all 3 sections first?
5. Some people suggested using self levelling compound on the concrete to get it totally flat?
6. Do I need to prime the concrete or screed with anything if I was to use glue.

Sorry for so many questions.

Should I pay a professional to do it or in this state can I have a go myself?

Thanks for any help. its much appreciated.
Scott

 

[WoodYouLike]

It's always best to create one type of underfloor

Your 3 inch new concrete needs at least 90 days to be dry enough to safely install wooden flooring on it (not matter what method you use). Rule of thumb: 1 inch takes 30 days.

Then I would suggest you glue down hardboard sheets on the concrete and nail hardboard sheets on the existing floorboards - creating one type of underfloor. Add 3mm foam underlayment and install the new wood floor floating.

 

[WoodYouLike]

Then I would suggest you glue down hardboard sheets on the concrete and nail hardboard sheets on the existing floorboards - creating one type of underfloor. Add 3mm foam underlayment and install the new wood floor floating.

Oops, wrote hardboard instead of plywood, my double Dutch mistake, sorry.
Use plywood sheets cut to small sheets (30 by 60cm max) or OSB sheets to glue to concrete floors.

 

[scottylowe]

Thanks 'WoodYouLike'!!

I hope you don't mind but what underlay would you recommend? I have not had this floating type floor suggested before. does it have any advantages / disadvantages to glue? By the way, your website is excellent.

I need to try and minimise the drying time and wondered if a dehumidifier would help? I was thinking of hiring one and leaving it running for a few weeks? or could that cause damage etc?

Cheers, Scott

PS, what is OSB?

 

[WoodYouLike]

We would recommend 3mm foam underlayment. As for advantage/disadvantage: we prefer the floating method over glueing. When something happens (and wood works, no matter what installation method you use) a floating floor is easier to rectify than a fully bonded floor. Plus the quality of the concrete floors here are mostly the 'weakest' link.

OSB stands for Oriented Strand Board

Thanks for the compliment

 

[scottylowe]

Thanks Woodyoulike.

I have been drying the room out with a dehumidifier 24/7 and also by leaving the doors open to create a through draft. The concrete seems to have dried out pretty well. I have emptied around 40 litres of water in a week.

However I appreciate that I should be waiting until the moisture level in the concrete is below a certain amount before laying the floor.

I have 2 questions really.

Could you suggest a reasonably cheap product on the market that I can buy so that I can test the moisture level is below a certain %? B&Q only stock one product and it looks rubbish.

Do you use a particular % that it has to be below before you fit the wooden floor?

Thanks again for your help, Scott

 

[WoodYouLike]

Concrete should be 2.1% or lower - mattysupra will know how much that is in relative humidity - we work out humidity on a different bases, as we've been used to in The Netherlands.
Try a hire centre for a proper tool, some do have them.

 

[mattysupra]

below 75% rh is british standard for any floor covering.
For wood it needs to BELOW 65% absolute max. Below 60% is what you want it at really.

Dial up F-BALL on the net. They do the correct hygrometer meter for around £100 quid. You wont be able to hire one.

 

[scottylowe]

Thanks guys. I originally had B&Q come over to quote to lay the solid wood floor because I wanted their opinion on my tiled floor and if it needed levelling. They told me what I knew already, in that I needed to dig the tiles up and put a proper floor down. They then offered to come around and check the mosture levels hoping I will pay them to fit the floor. So today I took them up on it as I can't afford to spend hundreds of pound on a moisture meter. I looked at that F-Ball site(thanks for the link) but could not work out where to buy one from???

Today they said that my floor was showing between 21% and 27%. When I asked what this was, he said that was the water content. When I mentioned RH he looked at me blankly.

I don't totally understand the differences in the way people measure RH but I guess he was referring to the low figure of 2.1 that you mentioned (woodyoulike) and not the high figure of 60% you mentioned (mattysupra) Would you guys be kind enough to explain??

He said that the measurement would have to go below 8% for him to fit it. He was planning to glue the wood down over all 3 surfaces!! I didn't mention your advice about a single sub floor type because I thought he would not like it.

I am bidding on a basic Protimeter hygrometer on ebay so hopefully should have something by the weekend.

Thanks again for all your help. I just wish I lived near you so I pay one of you guys to do it for me

 

[WoodYouLike]

I wouldn't have a clue what this B&Q guy is talking about! 21% - 27% needs to go down to 8%?
What type of moist meter did he use, did you notice? One where two pins are knocked into the concrete?

Glueing down on all three different types of underfloors? What's his guarantee?!?

 

[scottylowe]

I'm definitely not going to use them to lay the floor, I was just interested to see how they thought the floor was drying out (because I don't have a hygrometer yet).

Unfortunately I wasn't there. it was the girlfriend and she said the moisture meter was black with a curved top and he didn't put any prongs into the concrete.

could it have been radio based?

Thanks again

 

[WoodYouLike]

I wouldn't honestly know. We only use a proper professional moist meter (brought with us from The Netherlands that does the real thing )
Perhaps Mattysupra knows more about this typical meter?

If you plan to ask other to come round to quote for the works, perhaps our new fact sheet might come in handy?

 

[scottylowe]

OK, I have bought a second hand Protimeter Survey Master for £40 on ebay. It does ambient temperature and Relative humidity so I am ready to go.

I have set up a 40cm by 40cm square of clear Viscene taped down with 50mm duct tape to make it air tight. I have placed the protimeter inside and it is already showing readings of 71%. So I guess I need to keep the dehumidifier going and test every few days.

This is the right thing to do isn't it?

Thanks, Scott

PS thanks for the offer of the leaflet but I have already purchased the T&G wood from B&Q.

 

[mattysupra]

which Protimeter Survey Master did you buy, could do with the exact model number so i can tell you how to use. O and i have no idea what 21-27% means? Down to 8%? sounds a bit like a reading for wooden subfloor !

P.s £40 quid is a bargain, i might buy it off you when you have finished with it!

 

[scottylowe]

I think it is an old model. I bought it from a surveyor who was retiring.

I have found a similar model BLD7700 but its only available in the US.

http://www.professionalequipment.com/protimeter-hygromaster-hygrometer-bld4700/thermo-hygrometers/

http://www.gesensing.com/downloads/datasheets/920_081c.pdf

Thanks, Scott