How to fit a screw into a drilled big hole on wall?

Question

I am fitting a window blind on a wall. The wall is made of plaster board as far as I have known.

I have drilled a hole on wall bigger than the screw size.

The drilled hole on the wall has a diameter of 6mm

The screw I try to fit in has a diameter of 3mm

Here is the image of the drilled hole o the wall:

Here is the image of the screw with the window blind holder:

How do I fit the screw tightly and safely on the large drilled hole on wall?

Does the metal bracket offer more hole locations than you actually need? If so, perhaps you could just drill a new hole... — unutbu, Jan 20 '19 at 12:33
@unutbu, hole location at the top are not possible as the wall structure is weak. So the better option is to place the screw at the side — hunterex, Jan 20 '19 at 12:40
Can you [edit] your question to say what the wall is made of please? — Martin Bonner supports Monica, Jan 21 '19 at 09:32
@MartinBonner - indeed. I think far to many people are assuming everybody uses plasterboard/drywall everywhere... that wall looks far more like there's going to be brick or block behind it; in which case the answer would be far different [double-depth hole & longer screw to reach a rawl plug in the harder substrate] — Tetsujin, Jan 23 '19 at 11:44

score 43 · Answer 1 · edited Jan 23 '19 at 20:03

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For this you can use wall drilling anchors as shown in the images below. They are also known as wall plugs or rawl plugs. You can get them from any hardware shop.

edited Jan 23 '19 at 20:03

doppelgreener

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answered Jan 20 '19 at 17:45

Ramesh

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Also, in general, it's important to *check the load ratings* of anchors. In OP's case we can see the bracket and that limits the screw size (and anchor rating) so it's likely not an issue, but some blinds can be heavy and need larger anchors if going into drywall and not into a stud. – J... Jan 21 '19 at 14:14
An old trick is to put tooth picks or matches (without the combustible material) into the hole with some glue to fill it and the put put the screw in. But the plugs suggested is a much better solution. – nivs1978 Jan 22 '19 at 13:24
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These aren't really designed for plaster and will often crack the plaster when you put in the screw. One trick I found was to drill an even bigger hold in the plaster and then 'glue' an anchor in with joint compound for light duty needs. – JimmyJames Jan 22 '19 at 15:20
@JimmyJames Excellent point. Drywall anchors are really designed for drywall - they need the paper cladding to hold everything together. It's not clear if OP's wall is plaster/lath or drywall, but it looks like it could be either. If it's not drywall then these are definitely not suitable. – J... Jan 23 '19 at 12:58
@J... Yeah I'm not totally clear on what 'plaster board' is exactly. It could just be drywall. I had a plumbing access cover literally just drop off the wall one day because it was secured with screws into plaster which had cracked. Toggle bolts wouldn't work so I made holes larger than the drywall anchors and pushed them in with joint compound. Good enough to get the panel back in place but I would not use this technique for anything weight bearing. – JimmyJames Jan 23 '19 at 15:47
@JimmyJames - plasterboard is what the US calls 'drywall'. Same thing, different country. From the view of a European, the US seems to build with wood & 'drywall' whereas the EU builds with brick/block & 'wet' plaster. [Some new builds use drywall internally, but rarely on an outside wall] – Tetsujin Jan 23 '19 at 19:40
@Tetsujin OK, then these anchors are appropriate for 'plaster board'. In the US you would never use drywall or 'sheet rock' on an exterior wall either: it would be a disaster. In older homes, you will find plaster. My home was built in 39 and has plaster over lath board (the precursor to drywall.) – JimmyJames Jan 23 '19 at 22:15

Criggie · Answer 2 · 2019-01-23T00:00:11.670

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If there is no wood at all behind this spot anywhere, a plain wall anchor may rip out over time - curtain rails hold curtains which can be heavy, and can flap around in the wind creating vibration which slowly erodes plaster.

Here are some better designs of plasterboard anchor (drywall / sheet rock / gibralter board)

Rightmost is your standard cheap wall insert. It is supposed to flange out as the screw goes through the middle. Avoid where possible.
Second from right is a plastic toggle. These are pretty good because the two bits on the side fold and press against the inside of the plaster board. Ideally they should be sized for the thickness of your board.
Middle shows the large-radius coarse thread variant of the first one. These are astonishingly good. For double the radius you're getting at least four times the holding power.
Second from left is the toggle bolt. It needs a slightly bigger hole for the legs to go through, but when expanded inside the wall (as pictured, its got a spring) then there's a heap of holding area. Can hold medium sized mirrors.
Leftmost is a "mollybolt" and is an older design, harder to find. This one has four legs which fold out inside the wall when the screw is tightened. Note they do not adust for thickness - you need to size them for the thickness of the wallboard you're using. The pictured one is probably for half to 3/4 inch depth. A 1/4 inch or 6mm thick wallboard would have less shank on it.

Not pictured are the super-cheap tube ones that come with many cheap goods like smoke detectors. Not worth it at all.

Note, once installed, none of these plugs are going to come out without leaving a large hole.

Your other option is to plate the area under the curtain rail with some solid wood as reinforcement. 10mm thick would be a minimum IMO. Screw that to the studs where they cross, and then you can hang the curtain rail hooks whereever you need them.

edited Jan 23 '19 at 00:00

answered Jan 21 '19 at 10:13

Criggie

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Number 3 is extraordinarily strong. I use them whenever possible – vikingsteve Jan 22 '19 at 10:50
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I really love the middle anchor as well (E-Z Ancor) due to being able to install them quickly with a drill. Although they are described as "self-tapping", I prefer to give them a small pilot hole for alignment and then proceed to then drill all of the necessary anchors at once after preparing a surface. – Zhro Jan 22 '19 at 12:48
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I have found toggle bolts to be a good option for plaster. The others can end up cracking the plaster and falling out. – JimmyJames Jan 22 '19 at 15:22
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Don't even think of using standard plugs (rightmost) on plasterboard. They'll pull out and damage the board when they do. They are for use in bricks, where they hold superbly well. They also work in lightweight concrete blocks, but there are special versions (none of the above) which are sold explicitly for concrete blocks and which hold much better. – nigel222 Jan 22 '19 at 16:26
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@vikingsteve Which #3? #3 from the left or #3 from the right? – conman Jan 22 '19 at 19:52
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"none of these plugs are going to come out without leaving a large hole." #3 can be unscrewed the same way it went in - you could still consider that a large hole, I guess, but at least it's a clean one. – Random832 Jan 22 '19 at 20:32
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The left-most one is commonly known as a "molly bolt" in the US, and it used to be my favorite, for hollow drywall. They're hard to find anymore, though. – Hot Licks Jan 22 '19 at 22:44
@HotLicks Awesome thanks for that, I've updated the answer. You can just edit little titbits like that into an answer, and it gets reviewed/filtered before being published. – Criggie Jan 23 '19 at 00:02
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The only ones here suitable for plaster lath walls are the toggle bolt and molly bolt - the others are designed for drywall only and will not hold in a pure plaster wall. – J... Jan 23 '19 at 12:59

score 22 · Answer 3 · answered Jan 20 '19 at 19:29

22

As strange as this might sound, provided there's a stud back there, you can use toothpicks to fill in the hole. The toothpicks can bite into the screw, and provide friction against the surrounding wood.

If this is just drywall, use a drywall anchor like the other answers detailed

answered Jan 20 '19 at 19:29

Machavity

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Wooden matchsticks (with the tip removed) also work well. – mpdonadio Jan 20 '19 at 21:31
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Good tip. Before those plastic expanding plugs (like in the 50's), they used to pound round wood blocks into holes and put a wood screw in there. I've seen this in old block walls in old buildings. – element11 Jan 21 '19 at 14:43
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i use gofl tees :) – Quoc Vu Jan 21 '19 at 18:25
I had to do something similar (wood, not drywall) and I just bought a wooden dowel, cut to length and then jammed it in there with wood glue, the screw went in beautifully. – Welz Jan 22 '19 at 13:07

score 20 · Answer 4 · answered Jan 20 '19 at 12:24

The wall looks like plaster or drywall (aka sheetrock). You insert an "anchor" into the hole and thread a screw into the anchor. plastic anchors for plaster or drywall

But if there is solid wood of sufficient dimensions behind the plaster you use a long enough screw to thread into the wood. In your case, if you have good wood behind the plaster, but you have drilled too large a hole for the screw, just use a long enough anchor to fit an inch or more into the wood and thread in the screw. The anchor will expand as the screw goes in and will grip the sides of the hole in the wood.

Pooneil · Answer 5 · 2019-01-20T15:28:28.013

For oversized holes in wood, lightly tap in a glue coated dowel and redrill the screw hole. This may require widening the hole to the next available dowel size. For holes in un-backed drywall, use an anchor. (Your hardware store will have various kinds, but the simple plastic ones usually work fine for light loads.) If the particular hole in question try inserting an anchor first. If it has wood behind it that prevents use of an anchor, use the dowel and cut it flush to the drywall surface. Fill in any gaps between the dowel and the drywall with spackling, drywall mud or other filler recommended by your hardware store.

After waiting for the glue to dry, e.g. Overnight. – Harper - Reinstate Monica Jan 22 '19 at 21:56 — Harper - Reinstate Monica, Jan 22 '19 at 21:56

score 5 · Answer 6 · edited Jan 20 '19 at 23:23

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Instead of a dowel you could squirt some wood glue in hole and put wooded toothpicks in until you can't fit anymore. Wait a few hours and break off the toothpicks flush with the drywall. You should be able to use the original screw. I am a finish carpenter and have done this before.

edited Jan 20 '19 at 23:23

CCCBuilder

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answered Jan 20 '19 at 20:22

Scottieboombox

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Just seen the post below also mentioning the toothpicks. Screws work on compression so as long as the hole is filled with wood you'll be good – Scottieboombox Jan 20 '19 at 20:23

score 1 · Answer 7 · answered Jan 20 '19 at 15:04

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You can close up the big hole with some putty, and screw your screw after it dries. It is always recommended to use a plastic anchor for better wall grip.

answered Jan 20 '19 at 15:04

gil_mo

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Sounds like you're suggesting screwing into a repair made with putty? Putty is cosmetic, and will not hold a screw, It would all come out of the hole even if you tried this. – JPhi1618 Jan 21 '19 at 16:09
@JPhi1618, general-use drywall joint compound is as hard as drywall itself, when properly applied. – sleblanc Jan 21 '19 at 20:49
I think this answer is correct but need a lot of clarification on what types of putty are appropriate, and if any techniques (taping, etc) are needed. – Monica Apologists Get Out Jan 22 '19 at 14:40

score 1 · Answer 8 · edited Jan 21 '19 at 14:35

I think that using anchors, already mentioned, is the best solution. Besides the already mentioned answers, there are many different options available to you:

Drill an 8mm hole in the bracket and use a 7 mm screw into the 6mm hole.
Drill another hole in the bracket that is about a centimeter or so away from the original hole and insert a screw through that hole. Generally, the hole in the bracket should be 1 or 2 mm larger than the diameter of the screw.

score 0 · Answer 9 · answered Jan 21 '19 at 17:56

If your hole is too large to take a wall plug or anchor, then your best solution is to fill the hole with filler (e.g. Polyfilla), leave it to fully harden, and then redrill the hole to the correct size. You don't need to worry too much about filling the hole perfectly flush - it'll be covered by the plate anyway.

Looking at your hole though, I suspect you may just want a larger diameter.

Note that all screws into plasterboard/drywall should use some kind of appropriate wall plug or anchor for plasterboard. Contrary to spurious claims by some screw manufacturers, it is not possible to securely fasten a screw directly into plasterboard. The point loads on the screw thread will always weaken the plasterboard, and the fixing will inevitably pull loose after not very long. This is particularly going to be an issue for your blind - you don't want it falling off!

score 0 · Answer 10 · answered Jan 25 '19 at 10:13

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Here's a technique I learned from a my uncle who's 80 years old.

Find a a piece of wood that could be hammered into the hole.

hammer it and break the the part that's sticking out.

Done, time to drill the screw to the hole.

answered Jan 25 '19 at 10:13

adimona

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How to fit a screw into a drilled big hole on wall?

10 Answers10