How can I get screws out of ply floor with care?

[Moving15]

Started a pig of a job and wondering if anyone has a tip for the following.

Wooden floor boards with a ply sub floor overlaid and screwed in with hundreds of screws at 6 inch intervals. This was for a tiled floor which we have removed.

The problem is that the screws were blasted in with some super Dooper electrical tool and are so feel it's incredibly hard to lift them. We are using a combination of ratchet screwdriver, electrical screwdriver and hammer drill to get most out. Some are unreachable and those we chisel around and lift the ply risking damage to the boards underneath.

Any tips on this job? I'm hoping someone has done something similar?!

The reason for all this trouble is that there are lovely wide Georgian boards underneath and we are trying to preserve them!!

[Moving15]

• so deep not so feel!!

[engineersthumb]

Make sure tgat you clean out the screw heads with a pick or other small tool.
You could try running a circular saw through the ply. Set the depths to 1-2mm less than the ply cut it into small sections and lever up (having removed the screws you can). Although not the best saw I would recommend the evolution rage 3 model B, screwfix and others stock for about £50. It's a multi material blade steel/timber etc though hardened steel screws will dull/chip the blade bitting the occasional but burried one won't matter.

[engineersthumb]

Though Georgian boards are probably battered, bashed and drafty boards but each to their own:)

[PigletJohn]

most important thing is to use a driver with a tip that is a perfect fit and is not worn out. Size you can check easily if it is a slot, but if a cross, you need to check that it is Pozi (probably is) and which size.

If they are very tight you can loosen them the first half turn by hand, then go round with a cordless driver to wind them out. Wear leather gloves and use a driver with a flattened oval handle when working by hand. If you are buying screwdrivers, get ones with a chrome-vanadium shaft and hardened tips.

When the screwdriver tip starts to get worn, throw it away and use a new one.

[Moving15]

Thank you very much, we used your tips systematically and the job is done!