Floorboard->Joist screw removal problem

[vabex19]

Happy new year to those that have a good one.

I'm unable to remove multiple screws embedded deep within multiple floorboards into their joist. I suspect the installers used a bit too much pressure with the power tools and partially rounded the heads - as per the image, these are Tongue-Tite T-10.



Been using a ratchet power driver and electric screwdriver with original bits, plus a new 10-pack purchase of regular T-10s today, as the originals were wearing down. They're unable to catch in the head. Stuck too deep to access with pliers.

Also tried to hammer the driver gently as per the common removal methods for stuck screws, but all of the attempts haven't led to any luck. 3 days in so turning to possible help!

I have about 95% of the screws out elsewhere but there are these remaining 11 or so across 8 boards. These boards were only purchased brand new in August, with little in the way of spares, so desperate to prevent damage to too many - have already destroyed one that was jammed in too tight under a wall, had to jigsaw and chisel to remove it.

One option here is to jigsaw around the joist, just deep enough, then chisel/saw from above - but I have other boards with the same grief, so a solution would be ideal

 

[foxhole]

Hand driver in correct size?

 

[Harry Bloomfield]

Drill down the centre of the head, until the head comes off completely, raise the board, then use a pair of Mole self grips to unscrew it.

 

[lostinthelight]

I posted a vid in thread , https://www.diynot.com/diy/threads/need-to-get-old-boards-up.581334/

 

[Deleted member 174758]

This is one of the downsides to Torx screws, and to a lesser extent square drives and Pozis, over old-fashioned slotted screws (there are many advantages, though)and makes a good case for using slotted screws for removeable access covers in floors.

I can think of two possible solutions. First: use a Dremel tool or the like with a very thin grinding wheel to "saw" a slot across the tops of the screws and back them out with an old fashioned slotted screwdriver NOT a power driver. This will cause some minor damage to the board, although it is fairly minimal and can be filled. The Dremel grinding wheels are much thinner than anything you'll get on conventional angle grinder and will vause a lot less damage to the wood

Second: use a very long lever, ideally such as a Burke bar or a heavy garden spade positioned right next to the screw to lever the board up, bringing the screw with it (or if the head is small it might pop through the bottom). This can cause more damage. A Burke bar is not the same as a conventional prybar or a concrete point (and I also have a Hultafors 36in drop forged bar, one of the best of its' type, so I can compare directly) - if you ever use one you'll quickly realise that there is nothing else quite like them for heavy demo work.

This is a Burke bar

Marshalltown sell them as "Monster Bars". I have two, different sizes (a 3-1/2ft and an almost 5ft extra heavy one), and they make demolition and replacement of structural timbers a lot easier. Best tool I've ever found for taking floors out quickly and efficiently. When I left my last job several guys wanted to buy mine. In their dreams...

 

[blup]

Try tightening them first with a hand held screwdriver, that might loosen (some) of them. Otherwise brute force with a crowbar.

Blup

 

[vabex19]

Many thanks all, some good recommendations!

For this particular case, have actually been 'lucky' in that a light drilling to the head has enabled enough torque to be obtained to get some successful twists. Three or four drill+unscrew combinations has managed to get one of the tongued screws out (the second I got up enough to hacksaw the head off), at the cost of about 4-5 bits, with no damage beyond the slightly bigger hole from the drilling.

I'm encountering more of the problematic ones now mostly vertical to the board with the same issues (i.e. not tongued), but I'm trying to repeat the same methods that have so far resulted in progress. If these fail, will try these others in the thread - the 'sawing' in a fresh slot sounds like something I'd like to try just in general one day to see how easy it is regardless

Sadly the tighten first to attempt loosening hasn't worked on any of these, but I'm cautiously optimistic - 7 boards up since the new year! Will update the thread with the final progress and if anything else works, will hopefully give some light to anyone else with the same deal.

 

[foxhole]

Screw extractor would make short work of that .

 

[^woody^]

A flat bit, with a bit of filing if need be tends to fit these screws.

Also, try dampening the timber around the screw. You'll need a suitable container to soak the area around the screw so it absorbs into the joist

 

[opps]

Screw extractor would make short work of that .

I haven't had much luck with screw extractors in the past. I often resort to using a TCT drill to drill the head off.

 

[foxhole]

I haven't had much luck with screw extractors in the past. I often resort to using a TCT drill to drill the head off.

Never failed for me though rarely need if you have good technique .

 

[vabex19]

Success! Managed to get these all up and completed at the weekend.

Found the most efficient method while limiting board damage was to chisel around the affected screws and use the mole grips/locking pliers to bring it out. I can fill in these gouges with wood filler and some nicely sized shards with next to no integrity loss.

Only one board was unsuitable as two of the screws were so deep to the point of being unable to find the head I had to chisel a much larger area; this one ended up with seven total chisel points too, but luckily I have a good sized spare to replace it with.

Locking pliers were fantastic and the main solution in my case. Amazing the amount of additional hold they achieve versus regular pliers, and with a lot less effort.

Many thanks to all!