Advice on square-edge timber joining?

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I am refurbishing the floor of a 1930s flat. The original construction is of well-seasoned 140mm square-edged timber boards
nailed directly into a concrete floor (no embedded battens). Over the years the nails have worked loose.

The plan is to lift the boards & lay 7mm fibreboard underlay. The boards will then be re-layed in rows of 3-4 but bonded together as a
floating panel. To do this succesfully with square-edged timber boards I had thought of dowel pins & adhesive, biscuit cutting being an
option? The boards will then be sanded & finished.

Any suggestions or comments?
Someone had mentioned special double-ended nails but I have not come across any.

 

[fitter]

A biscuit joiner will be much faster and in my expeirence more accurate than dowels.

If you have not already thought of it, how are you going to keep the joints tight while the adhesive is setting?

If you havn't already got any ideas, what about flooring straps?, just tight enough before they bow.

just a thought

 

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Thanks Fitter.

I have some web/ratchet straps to hold them together. I guess this is what you meant. I was recommended Gripfill as it sets quickly, although others suggest Pink Grip.

Initially I thought dowels would be easier but now I may purchase a Biscuit Jointer.

 

[fitter]

I do not know pink grip but would have thought grip fill too thick. I'm sure it will be too thick to use on the biscuits

Screwfix £39.99 biscuit joiner if you did not already know.

 

[masona]

Just a thought, I'm always interested in new idea !

How about instead of 7mm insulation, use a 2mm thin roll insulation and use 6mm plywood and glue the flooring to the plywood ?

And you could screw down a temporary batten on the plywood and make 2 wedge to tighten the floor joint against the batten and you might be able to do a secret nailing using panel pins on the edge of the flooring.

 

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Thanks masona,

Good to have another point of view. I'm going with the 7mm as I have already bought it & I need maximum sound insulation, in both directions, without too much thickness & cost.

May use your idea elsewhere though...

 

[masona]

What we used to do, is to nail the panel pins into the edge of the flooring about half way in then cut the nail head off with a wire cutter plier then bang the 2 wood together to stop it lifting.