How to fix lime plaster on old house?

omgitschintu

Hello, we have stripped down wallpaper on an old house, built around 1930's. We have found that lime plaster (tested with some vinegar), was used on the inner walls which is possibly black ash mortar / breeze blocks.

It seems like a very thin coat of lime plaster and some of the lime plaster has blown leaving patches on the inner wall.

We want to ideally have a plush finish look with paint etc with a smooth wall.

What would be the easiest way to go about doing this? Do we need to remove all the lime plaster first or is there a way that we can leave what lime plaster is already there on the wall and coating over it, making it less messy, dusty etc.

Many thanks for your help!

JacobZ

Hi @omgitschintu,

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

There are two main options I can see here.

1. Leave the plaster in place, prime it to ensure it binds together, then skim coat over it with Hardwall Plaster then prime and paint.
2. Batten out the walls, screw plasterboard to the battens, then plaster the joins, sand, prime and paint.

Option 1 would maintain the same amount of space in the room, but the level of skill required is much greater.

Option 2 would lose a very small amount of space in the room, in the region of 30-35mm on each wall, but it would give you a nice flat surface to work with relative ease, with much lower skill required.

Of the two options, having done a fair amount of plastering myself, I would go with option 2, simply because skim coating an entire wall to get it perfectly flat is not easy and would require you to invest in some fairly expensive tools, like this Intex PlasterX 1000mm Drywall Skimmer, to get a quality finish.

To batten out the walls, you could use Siniat Furring Channel CGRIP Clips with Siniat 18 x 3600mm 0.42bmt Furring Channel. These clips have different slots which can be used to set the furring channel at different heights to account for any deviation in the walls. You would set them out at 450mm centres, with a track along the top and bottom of the wall, then fix your plasterboard to them.

Once the plasterboard is in place, you would finish them using the jointing system shown in our supplier CSR's video Installing Gyprock plasterboard - How to tape and set joints.

I hope this helps to clarify your options. If you have further questions or would like further guidance on either option, please let me know so I can assist further.

Jacob