How do you start the 1st row of T&G floor fit ?

[Chri5]

Groove toward wall with suitable expansion 2-3mm per metre = 10mm expansion gap.

First piece must need secret nail fixing on both edges, so how (since there's no luxury of 90 deg fix due to edge being 10mm off wall) do you fix the first run, and then the last run.

Flooring system is Elka and I intend to use:-

Since the expansion gap will be 25mm strip, do I just screw down vertically making sure the screw head is covered by the expansion strip cover ?

While I'm at it we intend to have a new fire installed, am I okay to tuck the flooring under the heath ?
The heath can be raised and centrally supported so that the hearths vertical edge is floating, thus isn't weight bearing on the floor.

 

[WoodYouLike]

How wide is your room and are you installing an solid Oak?
Can't advice on on the Elka system (still don't like the sound of it - in our 'books' screwing a floor 9 times out of 10 means "screwing" your floor but to be honest, we haven't used this system our selves) but the calculation for expansion gap is IMHO wrong.

Solid Oak: 3 - 4 mm per meter width of the room with a minimum of 10mm

You have to use the same width in expansion gap everywhere, so check if the space underneath your fireplace allows that.

 

[Chri5]

It's 4m x 5m so I'll make the gap 12 / 15mm.

Could you eloborate on the

in our 'books' screwing a floor 9 times out of 10 means "screwing" your floor

comment.

Existing floor is edwardian build pine suspended on joists, which in turn are on 36" pillars- so there's a lot of air under.

It's flat and I was going to use 3mm underlayment non DPC. The new flooring will extend away from the window, so will be at r/a to the old floor. I don't intend to lay ply skin as a surface for nail fixing A) due to being at r/a to existing floor and B) due to screw fixing being firmer than a nail.

As for the starting and finish lengths, any chance of an answer even if it's based on nails rather than screws

 

[WoodYouLike]

Now I'm confused (.com )

Using underlayment and nailing or screwing? Then you press the underlayment which ends up having no effect at all. It is either or: either you install floating and use underlayment OR you secret nail directly onto the existing floorboard without the use of underlayment.

If your new floor is solid oak, please make your expansion gap wider - at least 16 - 17mm and not 12mm.

Before we perhaps confuse each other even more, why does the "First piece must need secret nail fixing on both edges" - does this come from the instructions from the elka system?

 

[Chri5]

Maybe I'm just being an 4rse

The underlayment was intended as a part barrier, the original floor has a 30"+ gap to the base. The air temp down there is similar to outside. in winter if it's 10 deg, it's 10 degs under the floor.
I'd though that with the gaps between existing boards being 2mm+ it would be better to add a barrier for thermal reasons even if it does become a sandwich filling.

I'll increase the expansion gap, on all sides to 18mm (I can use off cuts from the flooring ).

Imagine starting a board, the 1st line on a floor-

The screw goes through the tongue. So if the board starts with the groove against the wall, the tongue end is fixed via secret nailing- but the groove end isn't.
Surely the 1st and last pieces should be secured on both sides of the T&G.

 

[WoodYouLike]

As explained above, we are not familiar with the Elka screw system. We frequently use - with plenty of different floor types, from solid wider than 100mm, all long lengths and most wood-engineered floors - the floating installation without using any nails (let alone screws! )

That's IMHO what you could do too: install a thermal barrier over the existing floor and install your new floor floating.

Hope this helps you in any way, sorry if that's not the case (we don't know everything )