Page 29 - Haddonstone

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6.3 Bedding and Jointing

Typically, cast stone products are clean water to reduce initial suction and
designed to be fixed with joint sizes of to prevent the cast stone from removing
between 5-10mm between the units. All too much moisture from the mortar. If
units should be laid and adjusted to final this does occur, there may be insufficient
position while the mortar is still plastic. water left in the mortar to fully hydrate
Mortar exuding from joints should be cut the mix and this will result in a dry,
away without smearing the face of the unit. powdery joint which may be substantially
Use load shedding (plastic) spacers to weaker than anticipated in terms of
support heavy stones and to prevent the bond strength,. However, it should be
mortar being extruded until it has cured noted that the use of water reducing
sufficiently. Locating holes for dowel joints admixtures or other water resistant
should be completely filled with either additives, introduced into the cast stone
mortar or resin. during manufacture may reduce the
effectiveness of spraying the joint with
• Do not leave pockets that could collect water. Ideally, the correct designation
water. Protect all unfinished masonry of mortar should be specified in the
with polythene. first instance, to suit the environmental
conditions.
• During hot dry weather, the faces to be
jointed should be lightly sprayed with

6.4 Cutting

Cast stone units should be designed to minimise on-site cutting. If it is unavoidable on site,
units should be cut with a diamond tipped masonry blade which should ideally be water
fed. Once cut, all units should be washed down to remove any excess dust. Due regard
should be given to protecting the operative in accordance with the current Health & Safety
requirements.