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

More documents

Recommendations

Info

Construction of movement joints Straight, unbonded vertical joints are the most common form of movement joint. They can be formed by butting the Celcon blocks against each other as a dry joint, or by leaving a 10mm gap filled with fibreboard. Bed joint reinforcement Movement joints should normally be continued through all surface finishes using stop beads (at one or both edges of the joint) to end the finish. Alternatively, a proprietary type of cover strip or an architrave pinned to one edge of the joint can be used. Where lateral stability demands continuity across the joint, propriety flat strip shear ties should be set in at 450mm maximum vertical centres. These should be set parallel to the plane of the wall, allowing the plain end to become de-bonded if movement occurs within the blockwork panel, thus creating a movement joint. For areas of high stress (e.g. at openings or where the blocks are under concentrated imposed loads) horizontal bed-joint reinforcement is recommended. It should be of adequate length to distribute stresses to nearby movement joints or into adjacent areas of blockwork. For example, it should extend at least 600mm into the adjacent blockwork each side of an opening. Reinforcement should normally have a mortar cover of a minimum of 13mm to internal faces of blockwork and 25mm to external faces. Entire wall panels may be reinforced so that movement joints which would otherwise be advisable can be omitted. Where a wall is supported by a floor which is itself subject to deflection, the first two courses of the wall should be reinforced. Only bed-joint reinforcement which has been specifically manufactured for use with thin layer mortar masonry should be used with the Celcon Thin-Joint System. Movement joints and bed-joint reinforcement around openings are not normally required for housing where independent finishes are being used, i.e. dry lining, weather boarding, tiles on battens etc. Our Technical Services Department will be pleased to give recommendations for specific projects. For further information on movement joints please see page 21 for contact details. Design Guidelines 4 15
4 Design Guidelines 16 Lintels Wall ties Detailing around windows When forming window openings, the blockwork can be taken up in full block heights and then cut blocks used to build up to sill level and lintel heights. Alternatively, whole blocks can be cut to allow the lintel to fit. Reveals can be formed by cutting the required block thickness to suit the reveal, applying the Celfix Mortar and then placing into position. Nailing may be required to temporarily support the first reveal block. Subsequent blocks can then be built above this as work proceeds. When using Celcon’s Thin-Joint System there are several types of lintels available, the most common of which are concrete, steel box and combined (or ‘top hat’) lintels. For cavity walls, whether they are of block/block or brick/block construction, the box lintel is recommended. If using a combined lintel, propping will be required until the outer skin is brought up to support the lintel and prevent it rotating. For solid wall constructions H+H Celcon recommend the combined type lintel with a 100mm block either side at lintel level. Bedding lintels on a traditional sand/cement mortar bed allows them to be more easily and accurately positioned. Being at the forefront of innovation H+H Celcon is currently developing reinforced aircrete lintels for use with solid wall construction techniques. These lintels will offer the benefits of speed of installation, the continuation of surface for finishing and remove any concerns regarding thermal bridging. There are several types of wall ties suitable for thin layer mortar masonry. Generally the most effective are helical type ties that can be driven into the face of the blockwork at a level which will course with the outer leaf mortar joint. Insulation can be placed against the inner leaf before wall ties are inserted. Helical type ties (as manufactured by Helifix) can also incorporate clips for partial fill insulation and are positioned as the outer leaf proceeds, thus minimising the risk of injury from projecting metal and reducing the build up of mortar snots. Ties are also available which may be laid in the thin-joint beds as block laying proceeds. This is particularly appropriate where both leaves are built together. All ties should conform to BS 1243, British Standard Draft for Development 140:Part 2, or a BBA Certificate. It is recommended that ties are not driven in to the wall until it is restrained at the head by the timber joists/flooring system. For further information on wall ties please see page 21 for contact details.
Page 1 and 2: ® The Celcon Thin-Joint System A D
Page 3 and 4: Aircrete combines superb thermal an
Page 5 and 6: Flexibility As with traditional bui
Page 7 and 8: Solid external walls Solid wall con
Page 9 and 10: ...and tools As with any new buildi
Page 11 and 12: 8 Provided the initial stages are f
Page 13 and 14: Sound insulation Thermal insulation
Page 15: 4 Design Guidelines 14 Wall junctio
Page 19 and 20: 6 Frequently Asked Questions 20 Wha
Page 21: ® H+H Celcon Limited Celcon House,

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?