Repointing sandstone crazy pattern patio - Is repointing feasible for sandstone

[bisbaz]

We have a crazy pattern sandstone patio that was installed in the 50's. We have two problems with the concrete pointing -- some of the pointing is loose and, in other sections, the sandstone seems to be wearing faster that the pointing, which is raised above the sandstone surface.

In asking my contractor about the feasibility of repointing the stone, he recommended ripping everything out and starting over. He said repointing would require use of a saw, which would be very difficult to use on the naturally shaped stone.

Is he correct?

[Tony McC]

Sounds as though the pointing mix was made harder than the stone. This is a bit of a problem in the same way that many cement mortar repointing projects to older buildings has proven to be a problem - when there's movement of the brickwork/stonework, the mortar is tougher than the masonry, so it's the masonry that cracks.

Could the old pointing be chiselled out? Your contractor is right from a feasibility perspective: it would be easier for a contractor keen to make a few bob to jack-hammer out the lot and start again, but if this is a DIY project that can be stretched out over a few weekends, then, as long as the old pointing can be broken out (I'd probably try using a kango hammer) there's no problem in re-pointing with a standard mortar, summat like 4:1 mix would be more than adequate.

[bisbaz]

Very helpful. Yes, I think the mortar used (in Arizona USA) was harder than the stone, and I will try to chisel it out. We like the sandstone and can put up with the fact that it is showing some age.