The screw refuses to go into the anchor in the concrete wall

[danni_e]

Hello everyone This is my first post here, and I found the forum the other day to get past some other problems that have arisen along the way in this process. I've tried searching but haven't found any information on this particular issue - if it exists and I've missed it, I apologize in advance. I'm very inexperienced when it comes to building, and you could probably say I'm all thumbs

I'm trying to mount a wall bracket for my new TV on the wall in my apartment. The building is new, only a year old, made of concrete, and I suspect it's reinforced in some way since the walls block radio waves like nothing else I've seen (I only have mobile phone coverage by the windows, if even then, and can't reach my WiFi if I just step outside the door).

The wall bracket came with accompanying screws and regular concrete plugs intended for 8 holes at 8 mm. The first challenge was immediate. I struggled for an hour with a hammer drill and couldn't make a single hole deep enough. After reading some threads here on the forum, I went out and got a rotary hammer, and then the holes were no big problem. It had to work a bit with a couple of the holes, but overall it went smoothly. It felt as if it stopped completely in a few places before moving on, as if the concrete contains different hard layers, sort of.

The plugs went into the holes without much problem - I had to tap them in the last bit, but not with much force. But then came the problem I'm stuck with right now - the screws won't go in properly. The first half went in very easily, but all the screws have gotten stuck firmly at about the same depth. If I try more by hand now, I just strip the screw heads. I have a really cheap screwdriver from CO of the brand CoTech, but it's not helping at all, it just spins.

In the military, we always said that everything can be solved with force, and if it can't be solved with force, it can be solved with more force, and if it can't be solved with more force, then you used too little force to begin with.

So - should I get a high-power screwdriver and go at it again? Or have I made some fundamental mistake that means I'm screwed (hahaha) no matter what? I've soon spent as much on tools and accessories as the motorized wall bracket itself cost... But I suppose I'll have use for them again...

I'm otherwise considering trying to wiggle out the plugs and widen the hole by a millimeter and trying again. On the other hand, I really want it to hold like a rock, because I have no use for a floor TV.

 

[Paul-Staffanstorp]

You absolutely should not widen the holes because then there will be no strength to the whole thing.

The question is whether you have really drilled as deep as the screws are long, because that's the only reason I can see for you not being able to insert the screws.
If you have drilled as deep as the screws are long, the drill bit went in, so the screws should also go in there, but if you only drilled so that the plugs go in, it’s no wonder you can’t get the screws in, since they would then stop against the concrete.

Maybe it’s a bit silly to ask if you have drilled as deep as the screws are long, but that’s the only thing I can see that could be wrong, and considering you yourself say you're not very handy, it's better to ask you this than to skip answering you.

 

[Thomas59]

The screws are usually longer than the plug, so if you've thought wrong, it can be as Paul writes. The hole is too shallow.

Another cause of error could be that you've drilled with a drill with too small a diameter for the plug you've chosen. You mention having to hammer in the plug. That shouldn't be necessary. Then it can indeed be tough to drive in the screw if it's concrete walls. It's possible, but if you have a weak screwdriver and bad bits, it can be as you describe.

Another source of error. Correct drill for the plug but too THICK a screw. It can, as in the example above, become simply too tight.

When I drill deeply into concrete, brick, or similar materials, I usually take a spray can with compressed air for cleaning and blow out with the "blow pipe" into the hole while vacuuming what comes out. This makes it easier to insert the plug.

 

[danni_e]

Thanks for the answers! Since the question is probably quite dumb we can likely assume that no answers are too dumb

Yeah, the screws are as long as the plugs and the plugs went all the way in, so the holes should reasonably be deep enough. Right now the screws are sticking out a couple of cm.

The plugs must expand for them to function properly, and could it be that this process is difficult in the hard wall?

Another thought that struck me is that there might be tension in the wall mount itself that's causing resistance. What I'm mounting right now is a mounting plate that the actual mount will be attached to. Since I'm not so experienced, the holes didn't end up exactly in the right spots, and the screws are a bit on the edge of the holes on the mounting plate itself. Could it therefore be the metal plate that is causing the obstruction? I don't really believe in that theory myself because it seems that issue should have presented itself earlier, before the screws were 3/4 into the holes, and besides, it applies to all the screws, even those that happen to land exactly in the middle of the holes on the plate.

The screws and plugs came together and belong together, and the instructions said the hole should be 8 mm, so it feels unlikely as the source of the problem.

But the holes are pretty deep, so it actually could be that there’s a lot of dirt and dust at the bottom - but that should have stopped the plug from going all the way in, right?

 

[MathiasS]

You hammered in the plug the last bit, which means the hole wasn't deep enough. Take a nail, or your favorite crochet hook, and check that you can insert the object as far as the screw is long.

Otherwise, I would probably focus on getting four screws in place. In terms of hole strength, one or possibly two are sufficient...

 

[Thomas59]

Thanks for the answers! Since the question is probably quite dumb, we can surely assume that no answers are too dumb

Sure, the screws are as long as the plugs and the plugs went all the way in, so the holes should reasonably be deep enough. Right now, the screws are sticking out a couple of cm.

The plugs need to expand for them to function as they should, and could it be that process that's difficult in the hard wall?

Another thought that struck me is that there might be tensions in the wall bracket itself stopping it right now. What I'm screwing up right now is a mounting plate that the actual fixture is supposed to be mounted on. Since I'm not very experienced, the holes weren't drilled exactly to the millimeter in the right places, and the screws sit a bit at the edge of the holes on the mounting plate. Could it therefore be the metal plate itself that's in the way? I don't really believe that theory myself since it feels like the problem should have shown itself earlier, before the screws were 3/4 of the way into the holes, and besides, it applies to all screws, even the ones that happen to land exactly in the middle of the holes on the plate.

The screws and the plugs came together and are meant to be used together, and the instructions said the hole should be 8 mm, so it feels like an unlikely source of error.

But the holes are quite deep, so it could actually be that there's a bunch of dirt and dust at the very end - but that should have prevented the plug from going all the way in, right?

Hmm....

1/ Remove the bracket and try again without the mounting frame

2/ Try with a screw of the same length but smaller diameter (just try it out). It is not recommended to use a screw not intended for the plug.

3/ Pull out a plug (pliers!) and clean. Then measure with the screw you intend to use to ensure it doesn't bottom out.

4/ Toss the screws that you've damaged the slots on and go buy REAL screws from a hardware store and real bits. Quality can vary significantly. Take PH (= regular cross slot) not PZ. PH can handle higher torque and has slightly deeper slots. The screwdriver should not be a limitation. It shouldn't be that difficult, and you can finish tightening with a screwdriver.

 

[Havsutsikt]

Here you have a classic example of when things don't always go as the manufacturer intended. Your wall is a dream wall for most, but your mounting plate seems very precise in the holes. It's likely very tight when you approach the wall with all the screws. If it's as sluggish as you describe, the risk is more than high that you'll break the screws. Additionally, I am doubtful if it's not as several have asked before, the screw may be too coarse for the plug. The problem is that it's very tight in the hole and it probably also tightens in the mounting plate, a new professional drill with new bits would probably break the screw. Enlarge the holes in the mounting plate a bit and get new screws if they start to wear out in the grooves. Then it's important to drive the entire screw at once; if you stop, it might pinch, and it's difficult to start again.

 

[danni_e]

What a quick and helpful forum, thank you so much

I unscrewed the screws and pulled out the plugs (the ones I could remove - the rest I drilled out) and checked. The hole was probably actually a little too shallow for the screws, but just a couple of millimeters too shallow, and the screws stuck out a couple of centimeters when they hit, so it was something else that stopped them.

I simply decided, on your advice, to get other plugs and screws. Also, slightly shorter than the ones I had before. It worked much better, even though it was still really tough to drive in the screws. My lousy screwdriver contributed nothing but noise and heat - it only managed the first third in.

But now the TV sits neatly and proudly on the wall. The screws in the actual wall will likely give up long after the mounting screws holding the TV part on the wall plate have given up and given way, so I'm not worried.

The most embarrassing part of the whole story was probably getting help from the sweet little blond girl at the local hardware store with infinitely more knowledge than me. Big thanks again to those who helped in this thread

 

[Thomas59]

What a quick and helpful forum, thank you so much

I unscrewed the screws and removed the plugs (the ones I could get out - the rest I drilled out) and checked. The hole was probably actually a bit too shallow for the screws, but only a few millimeters too shallow, and the screws stuck out a few centimeters when they were tight, so something else was stopping them.

I simply decided, after your advice, to get other plugs and screws. Also, slightly shorter than the ones I had before. It worked much better, even though it was still really tough to drive in the screws. My lousy screwdriver contributed nothing but noise and heat - it only managed the first third in.

But now the TV is neatly and majestically on the wall. The screws in the wall itself will likely give out long after the mounting screws holding the TV part on the wall plate have given up and quit, so I am not worried.

The most embarrassing part of the whole story was probably getting help from the sweet little blonde girl at the local hardware store with infinitely more savvy than me. Big thanks again to you who helped in this thread

Don't judge a book by its cover! Glad it worked out.

 

[svartöra]

Take PH (= regular crosshead) not PZ. PH handles higher torque and has slightly deeper grooves.

Isn't it the other way around? When you twist firmly, the screwdriver slips more easily in a Phillips head than in a pozidriv head?

 

[Thomas59]

Isn't it the other way around? If you twist properly, the screwdriver is more likely to slip in a Philips head than in a pozidriv head?

CHECKED: You're right. I went out to the tool bag and checked my big screwdriver and it is a Pozi.

I take back everything I previously said and claim the opposite:wow:

 

[_bergman_]

I recognize the situation from when I was installing my projector on the ceiling! Now it's resolved for you, but I still want to take the opportunity to recommend Torx screws, they are almost impossible to slip out of with the screwdriver. Gold when there's heavy torque! They can be found at hardware stores, often sold in boxes of at least 100, but if you ask nicely you can usually pick a few anyway =)

Just remember that you need the right bits for the screwdriver, but these are usually included in most bits sets. However, if you only have a regular screwdriver, you can't use these.