Fixing a deep render crack advice

Got a plaster crack on a stairs wall, having scraped it off - it seems there is a 5mm wide, deep crack about 5 cm all the way down to the brick.

The render seems to be stable enough and the previous owner seems to have filled it with silicone and patched over the top.

What can I use to deep fill that crack ? - expanding foam was one thought ? I cant think of anything else that would be able to go that deep - other than more silicone or decorators caulk

Any thoughts ?

I filled a deep crack last night, she's a bit sore this morning is Maureen

Got a plaster crack on a stairs wall, having scraped it off - it seems there is a 5mm wide, deep crack about 5 cm all the way down to the brick.

The render seems to be stable enough and the previous owner seems to have filled it with silicone and patched over the top.

What can I use to deep fill that crack ? - expanding foam was one thought ? I cant think of anything else that would be able to go that deep - other than more silicone or decorators caulk

Any thoughts ?

I'm no decorator or expert, but I had similar crack 20 years back as my new house settled. I just packed it with screwed up newspaper and filled ove the top of it before sanding down and touching up. To be honest, I had forgotten all about it until I read your thread, and no problems since.

If the render is blown, chase the crack out to the brickwork, so it’s say about2” wide. Use a weak mix, say 4:1,( or lime) and don’t forget to pva the brickwork. Scrape down when dry, and finish with filler.

If render is not blown, just use an internal polyfiller.

Silicone will not bond to mortar.

try gyproc easifill 20,fill out with it let it set 20 minutes then skim a tight coat over the top ,give a light samd.

Got a plaster crack on a stairs wall, having scraped it off - it seems there is a 5mm wide, deep crack about 5 cm all the way down to the brick.

The render seems to be stable enough and the previous owner seems to have filled it with silicone and patched over the top.

What can I use to deep fill that crack ? - expanding foam was one thought ? I cant think of anything else that would be able to go that deep - other than more silicone or decorators caulk

Any thoughts ?

Fairly wide given its short length. Go with a conventional filler and emulsion over it preferably. Keep and eye on it till the autumn of next year and if its not reopened you can forget about it. Its minor in subsidence terms but I would just check your builders insurance, although I wouldn't ring them.