How to create a seamless render from Brick Wall onto blueboard/FRC sheeting?

[Rappix]

I'm currently in the middle of a project to redo the wardrobes in my house. I had a long builtin floor to ceiling wardrobe from the 70s which was sagging and warped badly over time.

I've decided to replace them with Ikea Pax wardrobes however there will be a ~20cm gap to the ceiling which I'd like to fill in.

My preferred option would be to frame those 20cm , apply blueboard or FRC sheeting and then render over it so it transitions cleanly from the cement rendered brick wall.

I found there are a few acrylic multipurpose renders (e.g. Davco PM Render) which will adhere to brick/cement and blueboard and was hoping to use that to make a seamless transition

-White walls on the side are brick with cement render

- top section would be framed (potentially just the front leaving a gap at the back to save on cost)

-grey/blue is the blueboard with the applied render over the top

My main issues are that I don't know how the transtion between the brick to blueboard is going to hold up or if that will just crack. I haven't found anything online about anyone making such a transition which makes me wonder if that's just not achievable the way I am envisioning it

[MitchellMc]

Welcome to the Bunnings Workshop community @Rappix. It's wonderful to have you join us, and many thanks for your question about render transitions.

Due to joining the new and old render, you can't use jointing tape. I think you're best bet would be it ensure the outside timber pieces of your frame are screwed into the brick wall on either side and not just supported by the framing and roof. This will provide a rigid connection to the walls, and hopefully, there will be minimal movement between your frame and the existing brick walls. Set the frame and Blueboard slightly in from the front face of the render, and then coat the board to ensure you finish level with the render on either side. If your building has minimal movement, you might never experience cracking at this joint. However, if there is, you can cut the render back, create a breaker joint, and fill it with a flexible sealant like Sikaflex 11FC. The Sika 11FC can be stippled to mimic the render's texture.

Please let me know if you have any questions.

Mitchell
 

[Rappix]

Thanks Mitchell,

Much appreciate your response. Love the idea with the breaker joint as a backup plan should it crack and . Given it will only cover the top 20cm (236cm>255cm) it's well out of natural eye height and not very obvious should the joint not be absolutely perfect.