How to remove concrete screws

[JamesTheBeginner]

Hello, all. I'm hoping someone will give me some advice on how to remove screws put into a concrete floor.

There was a flood at my mother's house due to a broken pipe and the water destroyed one room.
I had to take out mouldy carpeting, padding, vinyl tiles, and particle board to get down to the concrete slab
the house is built on.

However, at some point my late father had to replace some of the particle board for some reason and put down
1/4"plywood instead in one section. He fastened the plywood to the concrete with some blue-colour Phillips-head screws.

Some of them seem to be easy to take out; they ARE moving when I try with the screwdriver. Unfortunately the majority
seem to be permanently embedded and I'm afraid of snapping the heads off.

Should I just cut them off level with the concrete with a hacksaw blade or is there some way to loosen them safely?

I'm going to be installing laminate flooring, so obviously I don't want any residual things sticking up to cause any bumps.

Here's a link to show what they look like close-up:

Flooring - Google Drive

drive.google.com

 

[havasu]

A nice little angle grinder cuts the screws flat to the concrete in no time at all. You could also pull them out with a claw hammer, but this will leave voids and a mess to deal with on your slab.

 

[Incognito]

An impact driver with the proper phillips bit might help with the screws. But if the heads burst off havasu has about the only solution I could think of-------demo bar to burst the wood off and then an angle grinder with a metal cut-off blade for any residual screw portions.

 

[DarisMulkin]

Tap them on the side with a hammer before trying to remove them. Not hard enough to knock the out of the hole and leave a pock mark. Also on philips screw sometime striking them strait down will loosen them up and you can remove them. After that grinder will probably be your best bet.

 

[C.J.]

Pry bar to apply upward force to the screw while using a drill/ impact to remove would be my first thought before I broke out the grinder to buzz things off. Less dust.

 

[Incognito]

Another thing worth mentioning I try when screws are stuck is first dig out the Phillips notch with a utility blade or anything sharp to clean it out thoroghly. Then, before I even try with an impact driver or drill motor I put the correct (almost always larger) Phillips screwdriver tip in and hit it quite hard into the notch before turning. This accomplishes two things. As mentioned above it will often loosen the screw from however it's wedged in and at the same time the Phillips tip of the screwdriver gets really secured into the slot. Then I'd try to at least get the screw turning with my Neanderthal forearms before resorting to power tools.

In commercial flooring the old doorstops and exterior thresholds are very consistently "locked" down where the apprentice is lost trying to remove them. I've demonstrated this technique many, many times and it works way more than 90% of the time. It's very rare I'd need a grinder. I'm also pretty good at whacking those down below the surface. As you give the screw/nail half a dozen hard whacks it generates heat which softens the metal and makes it even easier to flatten to zero. Those tricks are not all applicable to where you have plywood in the way but it just depends how many fasteners we're talking about what methods we'd use for demo. I never used battery operated tools so I didn't want to drag cords around a large commercial job. You get real efficient with hand tools when the temp. power box is 700' away.

 

[JPfloor]

Yes…We used to use an impact screwdriver for those old doorstops. Same principle you describe with a little extra turning power…

6 Bit Impact Screwdriver Set With Case

Amazing deals on this 6Bit Impact Screwdriver Set W/Case at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[highup]

One more trick that might work if you're using an impact driver, set the driver in its forward position like you're going to drive the thing farther into the concrete. Now, flip it in reverse an see if they come out easier. Sometimes that tiny bit of movement is enough to make a screw or a bolt move. That can work for automotive uses too.