Page 1 of 1

Posted: Tue Jan 03, 2006 1:31 pm
by sal
Hi Everyone!

We are laying a granite sett driveway, using rigid construction and mortared joints. Do we need to include expansion joints, as you would when build a stone wall? If so, could anyone offer advice as to how to go about this? The drive is about 30 metres long and 4 metres wide.

Posted: Tue Jan 03, 2006 1:43 pm
by Tony McC
Strictly speaking: yes. If you're using rigid laying and rigid jointng, then you need movement joints, which can be summat as simple as a single transverse joint filled with sand or flexcell and topped with, say, Thioflex or Pitch, every 6 metres or so.

However, many installations omit the movement joints on the grounds that the jointing is guaranteed to crack whatever you do, and these cracks will act as natural movement joints. This is all true, of course, but the purpose of a movement joint in this sort of construction is to focus the cracks where you want them to occur, rather than leaving it to fate.

If you wanted to reduce the rick of cracking to almost zero (you can never eliminate the risk completely) you can reduce the separation between the transverse joints to summat like 3 metres.