How to repair a hole in wall using a gib board?

[ngawai]

I have a large hole in my bedroom I decided to fix myself I have a question about the thickness about the gib board it seems to be a lot thicker in material than what's to work with, with the hole in my wall it's hard to explain but if I were to put a gib board down then plaster over it there would be a noticeable lip because the surface the gib boards screwed down to is so close to the surface lol I hope this makes sense!

[MitchellMc]

Welcome to the Bunnings Workshop community @ngawai. It's terrific to have you join us, and many thanks for your question about repair plasterboard.

It could be that the old board was 13mm and the new patch 10mm, or it could just be a slightly thicker older board style. I'd suggest you screw your patch board in place and then follow this guide to plaster over the top of it: How to patch plaster. The new plaster will bring your patch to the appropriate level and flush with the surrounding surface. You'll then be able to prime the repaired area and paint.

Please let me know if you have any questions.

Mitchell

[Dave-1]

Afternoon @ngawai 

I had to go look up "gib board" Even tho I have done a bunch of plastering I still dont know some terms. Withe your hole can you meausure the thickness of what is on the wall? As @MitchellMc says there are different sizes, and when I was googling the meaning I saw that you can buy plaster in the two sizes (13mm and 10mm) So hopefully there is a size to suit.

If there isnt you could measure the thickness, then use the plaster sheet you can find and add some packers to the back to bring it level with what you have before jointing it.

Step 1 is a large hole in a wall, Instea dof trying to cut to fit the hole. Cut the hole into a square or rectangle depending how big it is.

Step 2 is to give an example of what I mean.

Step 3 The two horizontal pieces are thin timber strips, longer then the holes width. These are glued to the backside of the plaster sheet (Various ways you can do that but I used liquid nails and it worked perfectly.

Step 4 You now have your square/rectangle cut hole, you have also glued a couple of timber slats across the hole (If you find timber post behind the hole even better) The 4 of tiny squares are spaces that together with the plaster you have make up the height of the existing plaster. So the plaster you have is 10mm thick, the old plaster is 13mm thick, that means your spacers need to be 2-3mm thick. I would suggest to look in the shims/spacer isle but this is the type of deal 75*100 by 3mm thick spacer. and glue them to the two timber rails. This gives you something to glue your new sheet of plaster onto.

Step 5 Now it becomes a standard hole to fix, Plaster, tape and a large flat spatula plus sandpaper and you will be able to have a smooth wall again

If I have gone down the wrong path just post a pic and Im sure there are some solutions that will work.

Dave