Crack in Mono

[coati13]

Hello there,

Hope you are doing well.

I've got a pretty large single story extension that was built about 4 years ago and there's a single vertical crack in the monocouche render from top to almost the bottom. Theres a brick structure underneath and where it is exposed, there's no cracking. I noticed the cracks years ago and had them filled about a year ago, but they've reappeared. It hasn't gotten any wider. I assume these are just from the new(at the time) extension settling?

Its just external and there's nothing on the inside walls. What would be the best thing to do to stop it happening again, or is this part and parcel of mono?

Thanks in advance!

 

[Alastairreid]

Should have had an expansion joint installed between the extension and existing.

 

[freddiemercurystwin]

What he said.

If you want to stop it you'll need to have a joint fitted.

 

[coati13]

Forgive my ignorance, does this mean an expansion joint just behind the render to stop movement? R e it would have to be taken back to brick, a joint put over the top and then rerendered?

 

[Alastairreid]

Not to stop movement, more to deal with any movement as the join is filled with flexible caulk.
Did they tie the extension into the existing house?

 

[coati13]

Yes the extension was tied into the existing house. I understand, so basically the render would have to be cut back, a expansion joint put in (if there isn't one already) and then an expansion bead/mesh in the render to stop it cracking again?

 

[Alastairreid]

That's about the bottom line yes.
And you will always see the render patch.