How to repair damp-damaged wall?

bdock

Hello,

I'm seeking advice on how to repair the wall. Rust has come through from damp spread from the shower. The regrouting has been addressed to stop the issue from continuing but I don't know where to start with wall repair given the rust from the window structure. It's a gyprock wall (not plaster). Is it as easy as bogging over or will I need to replace the metal strip around the window first?

Thanks,

Brandon

JacobZ

Hi Brandon (@bdock),

In a bathroom environment, any remaining rust will continue to react with moisture in the air, which means it can keep bleeding through new plaster and paint over time. As the metal angle is heavily rusted, it should be removed and replaced rather than patched over.

Start by throwing on some gloves, long protective clothing and eye protection, then cutting along both sides of the existing angle with a utility knife to break the paint and compound. Then carefully pry the metal angle up using a chisel and some pliers, noting that there will be resistance from staples or adhesive. Using some aviation snips, cut the centre of the angle then pry the two pieces away from the wall working towards the corners. It is easiest to simply remove the entire length of the effected angle then it is just the rust effected portion.

Once removed, clean the area thoroughly. Sand back any remaining rust or staining, make sure everything is dry, and remove any dust. If there is still visible staining, apply a stain blocking primer to help prevent it bleeding through later.

Cut your new metal angle bead to size using tin snips, then position it on the corner and fix it in place with nails or staples. Take your time to ensure it is straight using a level or straight edge before securing it fully. You can follow How To Attach And Plaster An External Angle for reference.

Apply a wet area base coat over both sides of the angle, making sure it is pressed well into the perforations, so it bonds properly. Allow this to dry, then lightly sand or scrape back any high spots.

Build up the area with one or two finishing coats, feathering each coat out wider to create a smooth transition. Sand between coats as needed until the surface is even.

Once everything is dry and smooth, apply a sealer or undercoat, then repaint to match the surrounding wall.

You can also refer to this general guide on How To Install Plasterboard if needed.

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

Jacob