How do I patch rendered interior walls in an old brick house?

[rachelb1357]

We have a 1930's brick house and I would like to patch (and then paint) some holes in the interior render caused by water damage (photos below). I have already tried to remove the old, crumbling render. What type of product should I use to patch the holes? I am not sure how to tell if the render is cement based or lime based. If it is lime based, do I need to use a different type of render?

I only have small area to fix, so I am hoping to find some type of pre-mixed product.

Thanks for your help!

[KatieC]

Hi @rachelb1357,

Welcome to the Bunnings Workshop community! It is great to have you and thank you for your question about repairing your interior render. Our resident DIY expert @EricL will be online later this afternoon to best assist with your question but let me tag members @Marty_greenshed and @Adam_W to see if they have any advice they'd like to share. In the meantime, check out this great Bunnings video on how to render. 

Keep us updated on your progress, we are always here to help.

Katie

[Marty_greenshed]

Hi @rachelb1357 ,

You could use this Polyfilla from bunnings, it's premixed.  Its good for render and can be used on interior and exterior.  Only apply it to the same level as your current render. Once you apply it, try and match the surface of the patch to the surface of the current render (stipple etc). 
You can use a variety of tools to try to match the surface, something like a wire brush or anything else that you can think of to use that would get the required finish.   
Yours looks quite smooth, with a few imperfections, so you should be able to recreate that quite easily by applying it smoothly and creating a couple of lower spots using a paddle pop stick or something similar to recreate your current renders finish.

Just make sure you brush away and remove any loose render around it before patching.

Good Luck

Marty

[EricL]

Hello @rachelb1357

It's great that you've received excellent advice from @Marty_greenshed. I'm in total agreement with the recommendation of using Poly 500g Exterior Masonry Poly. It's weather, UV, mould resistant and paintable. It can be tooled to a rendered texture or sanded to a smooth finish. One indicator that you have a lime-rendered wall is the actual mixture of the product. You'll see hairs or short fibres sticking out in the damaged sections of the hole. 

However, before you begin patching the hole, I suggest investigating the cause of the water leak and repairing it first. Once you've made your repairs it should be safe to patch the holes in the wall. Please make sure to wear safety gloves, goggles and a dust mask when doing your repairs and sanding the Polyfilla.

If you need further assistance, please let us know.

Eric

[rachelb1357]

Thank you Katie for the welcome and Eric and Marty for your excellent advice. I've bought the Polyfilla you suggested and I will be tackling the repair today!

[Jason]

How did you go @rachelb1357? It would be great to see your progress. And please let us know if you need any further assistance as we're here to help. 

This is exactly the kind of project we are trying to encourage members to knock off their to-do list during Fix-it Feb.

Jason

[rachelb1357]

Hi jason, I've completed patching the render. My technique improved as I progressed. I ended up using a sponge to match the finish on the chips around the door frame and these patches are invisible after painting. I also gap filled the door frame using Sellys no more gaps.

 

 

[EricL]

Hi @rachelb1357 

Thank you for posting that update on your wall patching project. The patch looks nice and level and the ones on your door are perfect. I'm sure once you paint these areas they will blend in nicely with the wall.

We look forward to seeing your next update.

Eric