Plug spinning in hole!

[Nanako]

Hi all, i'm drilling holes for shelves today in my bathroom, i'm using 8x65mm plugs, so i drilled a hole that deep, and actually a bit deeper. 830mm is the depth of this hole, i know because that's the entire length of the 8mm wide drill bit i used, i kept going hoping to hit some brickwork and never did

The drill went in all the way with no resistance, wasnt even on hammer mode, i hit nothing solid. Which seems impossible, gotta be some masonry in there somewhere
I put the plug in, i'm trying to turn the screw, and the plug is just spinning, deep in its hole. it isnt providing enough resistance. If i turn the screw, it turns, but nothing happens, no resistance, just spin

The screw can be wiggled around in there easily, its like the plug has burrowed a little cave in the plaster. Video: https://drive.google.com/file/d/1om6BmajFfWq_lpsGjNnOS8xwEGo3bXGj/view?usp=sharing (you may have to download unless you're viewing this several hours after i posted it

This is a problem
I need to install at this exact spot, i really don't wanna do it elsewhere
this shelf won't need to bear a lot of load honestly, its just gonna hold razors and shampoo bottles, but i've gotta get it screwed in

The other screw is perfectly fine, there's a solid wall there and no issues

 

[sparkymarka]

Only need 5mm red plug …it’s too big

 

[Nanako]

Only need 5mm red plug …it’s too big

i don't mean to doubt you, but im fairly sure putting a smaller plug into this hole would make the problem even worse, its an 8mm wide hole and im using an 8mm plug

 

[sparkymarka]

No…. You drilled the hole too big to start with ."

 

[Nanako]

No…. You drilled the hole too big to start with ."

i drilled the hole the size i needed for the plug. theres nothing wrong with the hole size, its the soft substrate not providing resistance

 

[endecotp]

You can either keep drilling until you reach something solid, or you can find a way to anchor in what you already have.

What do you actually know about the construction of the wall?

I would either (1) drill further, if I had a suitable drill, or (2) try to fit some sort of expanding fitting, like a plasterboard fitting (though not just against the back of the tile), or (3) fill as much of the hole and surrounding space with filler as possible and drill into that once it is hard, possibly with a smaller plug.

BTW, round-head screws would look better on that tray than the countersunk ones you have. If the gold-coloured bits of the shelf fit flush against the wall, I'd consider running a bead of silicone or similar along there as well.

 

[Nanako]

You can either keep drilling until you reach something solid, or you can find a way to anchor in what you already have.

What do you actually know about the construction of the wall?

I would either (1) drill further, if I had a suitable drill, or (2) try to fit some sort of expanding fitting, like a plasterboard fitting (though not just against the back of the tile), or (3) fill as much of the hole and surrounding space with filler as possible and drill into that once it is hard, possibly with a smaller plug.

BTW, round-head screws would look better on that tray than the countersunk ones you have. If the gold-coloured bits of the shelf fit flush against the wall, I'd consider running a bead of silicone or similar along there as well.

i'm gonna do option 3 then, i know filler

these things will not fit flush, no worries there, at this point i'm less worried about aesthetics than about getting the damn thing installed

 

[Murdochcat]

Pull the plugs out and push them in again with a couple of matches beside them

 

[Nanako]

although, why should i fill the hole and redrill it

What if i just put filler in and then put the plug in while its still wet, let it solidify before adding the screw

 

[Nanako]

No…. You drilled the hole too big to start with ."

Also just to clear up any confusion here:

I drilled an 8mm hole, for an 8mm plug
And then afterwards, i widened -only the entrance- of the hole to 10mm, because it is drilled through tile and i know that tiles can crack if a plug expands in them

The plugs come with 5mm screws they are designed for
The plug is not visible here because it is deeper inside the hole

Nothing here is improperly sized, the hole is the perfect size

or at least, it was before it seems to have burrowed a deeper cavity in the soft material

 

[StephenStephen]

Do you know what the construction of the wall is?

My guess, and it is just a wild guess, is that it's (from the wall surface inwards) tile, plasterboard, stud frame with void in between, brick/stone.

To clear up the size confusion, the suggestion is that you've drilled the hole too big, because you're using rawlplugs that are too big for the job. So the suggestion is that the hole is therefore improperly sized for the job.
Anyway - that's water under the bridge - more crucially - what do you know about the wall?

 

[Nanako]

Do you know what the construction of the wall is?

My guess, and it is just a wild guess, is that it's (from the wall surface inwards) tile, plasterboard, stud frame with void in between, brick/stone.

To clear up the size confusion, the suggestion is that you've drilled the hole too big, because you're using rawlplugs that are too big for the job. So the suggestion is that the hole is therefore improperly sized for the job.
Anyway - that's water under the bridge - more crucially - what do you know about the wall?

A good question. "know" is a strong term, but there are some things i suspect about the wall. For clarity, we will call it the Left Wall, since it is to the left as you enter the bathroom

Firstly, i believe it is not plasterboard.
This is because the back wall of the bathroom which faces the exterior wall, IS plasterboard, i know this for certain, ive seen it reassembled recently. And a part of that wall has the same tiles on it

I knock on those tiles, they have a hollow sound
I knock on the left wall, they do not have the same hollow sound, it resounds much less

Next to the left wall (opposite the back wall) is an interior wall that i know for certain is made of double layered brick, because ive seen it exposed during recent work. And also because it put up a ton of resistance and i had to turn on hammer mode to drill into it
There are tiles on the interior wall too, and parts of them sound the same as the left wall.
I know the interior wall is full of voids because thats where the wires and pipes for the electric shower run

The left wall has some voids too, knocking on it does not produce the same consistent sound at all parts. I don't believe it has any wires or pipes in it though, the voids are probably residual. Also worth noting that the emptiest parts of the left wall still do not sound as hollow as the plasterboard back wall

The part i've drilled into here is approximately in the middle in terms of firmness, its neither one of the hollow voids, nor one of the completely resistant solid parts. And a lot of matter came out when i drilled it

Based on all available evidence, i suspect that the part of the left wall i drilled into, was solid plaster all the way into the 830mm depth

I am certain there is brick somewhere behind it, because behind the left wall is the kitchen and tool closet. This part i've drilled specifically backs onto the tool closet, and its walls are clearly made of brick. But the exact distance i'd have to drill to reach that is unknown

Given the very low loadbearing requirements of this shelf, i don't think that drilling into masonry is necessary, a plug buried in plaster will be strong enough. And given how deep i've drilled already, i don't think reaching masonry is even feasible

 

[Alec_t]

830mm depth

Really? The drill tip is likely out in the garden, or in your neighbours's property!

 

[Nanako]

although, why should i fill the hole and redrill it

What if i just put filler in and then put the plug in while its still wet, let it solidify before adding the screw

hooray, this plan worked, the plug in the filled hole did not move, and one shelf is now fully installed to my satisfaction
yea it would have looked nicer with rounded screws, but its not a big deal, im happy

time to repeat the process several more times

 

[Nanako]

Really? The drill tip is likely out in the garden, or in your neighbours's property!

hah, this is an internal wall, it comes out in my tool cupboard. nothing poking through there!