Advice sought on patching medium sized platerboard hole

[jkn]

Hi All I need to patch a plasterboard hole on our bathroom ceiling, due to water damage from above. I'm seeking advice on the best way to do this.

I'm not yet 100% sure of the exact size (haven't cut back all the plaster yet) but I'd guess about 600mm by 450mm, ie, more that a joist's width.

I'm wondering if it's feasible to do something like the uk.d-i-y wiki suggests for small holes:

# Using a bevel edged hole and matching plug

for this rather larger one? ie chamfer the sides on the hole and the new piece of plasterboard, and glue it in. I go have a multi-tool. but I wonder about getting the accuracy exact enough for a good fit.

If not, do I have to bite the bullet and fit noggins between the joists to support the edges of the patch piece and the existing plaster, or is there another shortcut I might adopt?

Thanks for any pointers

J^n

[tabbypurr]

I'd stick wood behind the hole, quicker & easier & ore robust.

NT

[Andy Burns]

How good nick is the rest of the ceiling?

Maybe easier to overboard the whole ceiling, instead of patching ...

[Huge]

I usually stick a piece through the hole and "glue" it over the top with Polyfilla (other cellulose fillers are available), then when that's dry, roughly stick a piece to that, then when that's dry, fill round the edges. Takes a while, but no accuracy required.

[alan_m]

Various suggestions on Youtube

[The Natural Philosopher]

No. All you need to do is get a bit of plasterbaord wedged in there and use plaster to skim over it.

How you do that is a moiveablke feast. Ive herad tell of peoiple using bits of lath screwed to the back that are rotated beind the existing board. If you have a jost to nail to, nail away. Plaster is an excellent adhesive and you will need to skim anyway

[The Natural Philosopher]

What an incredibly stupid suggestion

[Brian Gaff]

In my bedroom they cut way back to the size of a new bit of plasterboard then affixed it and dressed the joins with some stuff, then redecorated it. Brian

[John Rumm]

The technique described there works best where you have a small hole, and it might be more tricky to get a timber behind etc.

In your case it sounds like you have plenty of space to play with.

You don't necessarily need proper noggings - just some battens behind the patch will usually do the trick - as shown at the start of the article.

All you need to do is support the patch and keep it at least co-planer with the existing board (you may not be able to get it exactly flush if the existing board is skimmed and you are putting in a new patch - although you can add packers on top of the battens to get a closer match).

[John Rumm]

A perfectly reasonable suggestion in some cases... if the existing ceiling is already poor in a number of places or has multiple holes etc, then over boarding can fix a number of problems in one hit.

[The Natural Philosopher]

and you dont think that if that were the case the OP would have had secind thiughts about pacthing it?Perhaps you are right, and the average IQ of this NG is around 30..

[Dave W]

I patched such a hole in my bathroom ceiling, under a leaking flat roof, by putting a piece of expanded aluminium mesh above the hole, then applying plaster to squish through the holes. I will have to do it again though as another leak has occurred, although I can't see any hole in the roof!

I also patched a much larger hole in my kitchen ceiling, below a leaking hot water cylinder in the room above, by cutting a piece of plasterboard to roughly fit the irregular hole, and holding it up by means of large washers held by countersunk screws into the lathes. Then plastering over the cracks and bumps.

[Rob Morley]

WHS

[John Rumm]

Maybe, maybe not - sometimes you can get too close to the problem at hand to step back (possibly literally) and look at the bigger picture.

Leave and raise it then.

[Dave Liquorice]

Loads of ways. How long do you want the patch to remain "invisible". The edges really need supporting above and ideally taping over below before skiming if you don't want cracks to appear along the joint lines in a year or three.

Think I'd cut back as required to get rid of the knackeredd PB, extend edges to the joists. Temp fix an over sized bit of PB over the hole, cut through both layers with mutltitool giving overlap onto joists, remove the offcuts, fix battens to edges that are unsupported (50x20 ish, 25 exposed 25 on existing ceiling, PB screws), fit and fix the just the right size bit of PB, skim. Taping over the joins if you can find some suitably strong and thin tape.