The Celcon Thin-Joint System A Definitive Guide - Masonry First

4 Design Guidelines
14
Wall junctions
Walls should normally be bonded in at returns and
junctions unless a movement joint is required.
Where a section of wall has to be constructed after other work,
bonding can be replaced by a straight joint, providing proprietary flat
strip shear ties are built in across the joint (as shown) or helical ties driven in during
construction. This method of jointing is preferable to bonding under circumstances where
differential movement is likely to occur (e.g. where sections of wall are built off different
foundations). Where an inner leaf is built prior to the outer leaf, helical ties can be
driven through the inner leaf into the internal partition (penetration into the partition
should be a minimum of 50mm). These ties can be positioned irrespective of coursing.
Where enhanced sound insulation is required, an acoustic sealant can be applied to each
side of the vertical straight joint.
3M 3
Movement joints
As for all masonry walls, the accommodation of movement should be
considered at the design stage. The following general recommendations
apply to aircrete:
- Walls in excess of 6m long should be designed as a series
of panels separated by movement joints at not more than
6m centres
- The position of the first joint from the corner should be
designed to be within 3m of a corner or fixed end
- An alternative to movement joints is the use of bed-joint
reinforcement, where entire wall panels are reinforced.
This alternative is recommended particularly for an
externally rendered solid wall construction or an outer
leaf of rendered blockwork. This also applies to separating
walls which should not contain movement joints
6M