How do I fix this hole/chipping in a rendered wall with a metal surface?

[BigMistake]

Hi there,

Unfortunately, yesterday I created a hole in the paint/render of an interior brick wall from a nerf dart. This was surprising to me as I thought there was solid brick behind every surface of the wall. Removing the loose and cracked debris as part of advice on patching brick walls I realised that this very small area is not brick, but instead a thin sheet of metal extending from the light switch. None of the other light switches in the house have this.

I’ve had people suggest covering the metal with mesh tape before patching, using a mesh patch, and even watered down pva glue. I know that once the patch is done I will need to get a paint match, so I have saved a large chunk of the paint.

I would greatly appreciate any help with how to go about this repair! Thank you so much.

 

 

 

[JacobZ]

Hi @BigMistake,

Welcome to the Bunnings Workshop community, it is wonderful to have you with us.

Getting render to stick to metal requires a mechanical key and the right bonding system. Render will not adhere directly to smooth metal on its own.

In your situation, you would also need to reinforce the gap between the metal plate and the rest of the wall surface. This would likely require you to remove some more material on the right side of the gap, so you can attach some mesh tape to bridge the gap.

First, the metal must be clean, dry, and free of oil, rust, or loose coatings. The surface should be cleaned with a degreaser to ensure nothing interferes with adhesion.

You would then need to prime the surface to ensure the render adheres. Unfortunately, as render is not typically applied over metal, there is no primer that I can find that specifically states it can be used over metal. I suspect watered-down PVA glue or something like BondCrete would offer increased adhesion, but I couldn't guarantee it would work.

You could then use a patching render, such as Dunlop Premix Render Joint And Patch to fix the patch.

Allow me to tag @Nailbag to see if he has any thoughts on the best way to go about this repair.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob