What to do if a drilled hole goes wrong but you can't resite

[dodo]

I tried a plasterboard cavity fixing which created a big 20mm dia hole, only to find it didn't work. I think this is because there's no cavity - the plasterboard is attached directly to insulation board.
Anyway, I know I can fill the hole (polyfilla etc) but what's best to use, given that I still need to fix a screw in the centre of that spot?
And what kind of fixing should I use subsequently?

[kbrownie]

dodo,
i'd fill hole with finishing plaster, THE BEST FIXING to use hollow wall anchors, they can be used for all types of duties from light-heavy. After you have filled hole try spotting the fixing while plaster is still wet, don't tighten fixing up until plaster is hard. Then tighten fixing up first so so the barrel grabs the inside of wall, then remove screw and fix up what ever you are fixing to wall!
Regards
KB

[dodo]

By spotting do you mean partially inserting the fixing while the plaster is till wet?

Also - don't I need a hollow wall to use a hollow wall anchor?
My wall seems to be have no cavity It's an exterior wall but lined with insulation board and then plasterboard.

I can't find any fixings specifically for this wall construction.

[kbrownie]

Hi,
by spotting! I mean whist plaster is wet put fixing where you need it to be in wall, to aviod having to drill it and may be knocking the patched area about so you don't end up with 20mm hole again.
So you have a dot'n'dab wall, which means that you plasterboard is stuck to a block wall behind it.
Hollow wall anchors sizes can go down to at least 50mm and i'm sure i've used 3.5mm ones. So this will depend on gap between board and wall, so i'd suggest using the fischer type fixing and drill not only in board but wall too, you will need a masonary bit to do this.
If you click onto the picture of the plastic raw plug that appears on these pages it will link you to screwfix site, which will display different types of fixing that are suitable to your application
I hope this is helpfull
KB

[VTSravanelli]

Almost a perfect answer for me too....

iv been trying to fit a towel radiator in the bathroom, and i tried to use anchor fittings for hollow walls, however as iv tightened the screw, rather than the back of the head anchoring into the plasterboard and letting the "legs" spread in the cavity, it has chewed the plasterboard and just kept spinning.

so now im left with a (very) rough 12mm hole (i just yanked the anchor fitting back out in a strop) and the 10mm anchor fittings just wont go flush with the wall anymore.

and because the bathroom is covered in newly fitted cladding, i dont particularly want to move the position of the radiator.

will i be able to use a finishing plaster and spot the anchor fittings even though it is a hollow wall (i did need to drill into the breezeblock a little to let the anchor go flush with the wall)

or are there any other options for me? push come to shove i have some cladding spare and could roughly repair the two holes i have cut and move elsewhere, or final and very last option would be to replace a full wall of cladding, & move the radiator and start afresh! :oops: any help would be massive!

[chris_on_tour2002]

i wouldn't use the above technique to secure a towel rail - too heavy. if it's breeze block then why not go into that and use longer fixings?

[VTSravanelli]

because of the length of the "supports" that im fixing to the wall...

if i went right back into the breeze block the radiator would almost be flush with the wall, and being that i have the cladding it could cause deformation?

thats why i was asking about the repair of the plaster - because its that that i really need to secure the support fixings to, im already loosing 5/10mm because of the cladding?

[chris_on_tour2002]

i am not suggesting that you sink the 'supports' into the wall. they can stay on the surface of the plasterboard. using longer screws and rawlplugs you can screw into the blockwork behind.

[VTSravanelli]

ah right, apologies dude, think i missed your point the first time...

what is the longest screws i could use without the weight of the radiator winning over the "grip" of the rawlplugs? without measuring there is a small gap between my plasterboard and the breeze. so the tension would be greatly increased wouldnt it?

are there any screws/rawlplugs you could recommend?

i just wish id stuck to my original plan of using rawlplugs instead of trying with the metal anchor screws!!

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