Cast Stone mortar joint - poor quality, any remedy?

[maxdavie]

Hello,

 

We've had some very special cast stone plinth blocks installed in a sandy 'bath' colour. Our groundworker - a bricklayer by trade - has installed them with a 10mm joint using yellow mortar (despite us having a convo on site re the joints being as thin as possible, ie 3mm and in a colour-matched mortar). Given that we wanted to achieve something that looks seamless, I think it looks awful! - see photos at bottom. 

 

I'm going to ask him to repoint with a colour-matched mortar - sadly it'll be too late to achieve a thinner joint now. 

Has anyone worked with cast stone blocks who could offer some advice about how to point them neatly and what a good mortar to use is? 

 

 

Thanks! 

 

 

 

 

 

[bassanclan]

We used cast stone cills some of which came in two halves. 3mm joint is not practical, 8mm would probably be the minimum, but if the plinth lines up to the corners it suggests that the designers specified 10mm.

 

In my case the cast stone manufacturer provided the sand and white cement which was colour matched.

[nod]

The cast stone manufacture Suplied us with a bag of dry mix for pointing and chips 

[maxdavie]

1 hour ago, bassanclan said:

 3mm joint is not practical

Is this just because its physically difficult? Or does it not lock the block sufficiently? 

 

[bassanclan]

Its not physically difficult. There are many thin joint systems which are used on blockwork etc with 3mm joints, but they use a glue rather than sand and cement