Restraints for Stone Cladding

Reference should be made to BS 8298-2: 2020 “Design and installation of natural stone cladding and lining”, when selecting ties for restraining stone cladding. Restraints should be designed to resist wind loads and any imposed loads from, for example, window cleaning equipment.

Each stone will normally be restrained in four places, two at the top and two at the bottom. These are usually situated in the horizontal joints. The restraints should be located in pre-formed mortises or holes positioned in the centre of the thickness of the stone panel, and located at 1/4 points for half bonded stones and 1/5 points for stack bonded stones. Restraints should be kept at least 75mm from any corner with the peripheral distances between any two restraints not exceeding 1200mm.

The embedment of restraint dowels and lips into the stone should be at least 20mm. To achieve this, lipped ties (LPBs) have a 25mm downstand and dowelled ties (DPBs and YPBs) have 60mm long dowels.

Drip Positions

Due to the wide varieties of design cavity and stone and insulation thickness, it is not possible to standardise the position of any required drip. If a drip is required (e.g. YDB) please specify the position clearly, indicating from which end of the tie the measurement is taken.

Standard Stone Fixings

YDB

Min length 120mm
6x60mm loose dowel

YPB

Min length 40mm
6x60mm loose dowel

YP21

Min length 40mm
6x60mm loose dowel

MP21

Min length 70mm
6x60mm loose dowel

MDS

Min length 140mm
6x60 loose dowel

MPB

Min length 70mm
6x60mm loose dowel

LP21

Min length 35mm

LPB

Min length 40mm

LPL

Min length 75mm

ZDS

Min length 110mm

DP21

Min length 40mm
6x60mm welded dowel

DPB

Min length 40mm
6x60mm welded dowel

DDS

Min length 120mm
6x60mm welded dowel

Wire Ties

Wire ties are manufactured from 3mm and 5mm diameter wire for the fixing of thin marble.

Ancon Push–Off Bolt

This fixing provides the centre of stone panels with additional resistance to the effects of impact loads, blast loads and positive wind pressure. Its mechanical expander fixes securely into the inner leaf while the neoprene pad cushions the external stone panel and prevents rattling. The Push-Off Bolt is supplied in a variety of lengths to suit cavities from 100 to 200mm and can be fixed to both concrete and blockwork.

Ancon 2000

Ancon 2000 restraint fixings are simple and secure method of fixing thin facing slabs (20-40mm).