Posted: Sun Nov 15, 2009 9:15 pm
There is no definitive answer to LLL's query; it's a matter of personal choice. On residential driveways, I always preferred mortared joints, whether it's a straight or an arc. I think it looks better, it helps hide those minor variations in kerbs widths, and when I was contracting it allowed me to charge more per metre than competitor contractors who were close/butt jointing.
The nearest statement there is to "definitive" would be BS 7533:6 which requires kerbs to have a minimum joint width of 2mm (I think: I haven't got it with me, so it might be 3mm). This is intended to reduce spalling, but how many small CBP kerbs (as opposed to road kerbs) are laid with a 2-3mm joint? Most of those I look at are butt-jointed, ie, the kerb units are in direct contact with their neighbours.
The nearest statement there is to "definitive" would be BS 7533:6 which requires kerbs to have a minimum joint width of 2mm (I think: I haven't got it with me, so it might be 3mm). This is intended to reduce spalling, but how many small CBP kerbs (as opposed to road kerbs) are laid with a 2-3mm joint? Most of those I look at are butt-jointed, ie, the kerb units are in direct contact with their neighbours.