BS 8212:1988 download free.Dry lining and partitioning using gypsum plasterboard.
1 Scope
BS 8212 code of practice gives recom mendations for dry lining to walls, ceilings and partitioning using gypsum wallboard. Composite products such as gypsum plasterboard backed with insulation materials are also included.
This code does not deal with linings to heated ceilings. NOTE. The titles of the publications referred to in this standard are listed on the inside back cover.
2 Definitions
For the purposes of this code the definitions given in BS 1191: Parts 1 and 2, BS 1230: Part 1, BS 4022, BS 4049 and BS 6100: Part 1 apply together with the following.
2.1 face. Surface of gypsum plasterboard on which the paper extends continuously to cover the edges.
2.2 back. Surface of gypsum plasterboard having a double thickness of paper along the two edges.
2.3 insulating gypsum wallboard. Gypsum wallboard backed with a film having a surface of low emissivity e.g. aluminium, to improve thermal insulation when used in conjunction with an air space.
2.4 thermal wallboard laminate. Gypsum wallboard backed with an insulating material such as expanded polystyrene, polyurethane, phenolformaldehyde foam or manmade mineral fibre materials.
2.5 predecorated gypsum wallboard. Gypsum wallboard faced with either paper or cloth backed vinyl film.
2.6 prefabricated gypsum wallboard panel partitions. Prefabricated gypsum wallboard panels, manufactured in accordance with the requirements of BS 4022 and nailed to timber framing members.
2.7 laminated gypsum plasterboard partitions. Three or more layers of gypsum wallboard bonded together with gypsum based adhesive and fixed at the perimeter to a steel or timber frame.
2.8 relocatable partitions. Partitions that permit reassembly after removal and relocation.
2.9 metal furring channel. Galvanized steel section for the attachment of wallboard linings to solid backgrounds.
2.10 resilient fixing channel. Galvanized steel section for securing gypsum wallboard to the supporting background by a resilient mounting.
2.11 nailable fixing plug. Galvanized steel nail with an expandable plastics sleeve.
2.12 general purpose bonding compound. Adhesive made
from retarded calcium sulphate hemihydrate and additives.
2.13 multi-purpose adhesive. Adhesive made from
retarded calcium sulphate hemihydrate, additives and
lightweight aggregate.
10 Partitions
10.1 General
Timber and steel frameworks can be used for the fixing of gypsum wallboard to form a lightweiit internal partition system. The system allows for services to be installed within the framework.
Various requirements for sound insulation and fire resistance can be achieved by the use of different thicknesses and combinations of gypsum wallboard linings. The system is normally constructed with taped joints to give a flush finish. It can be used to carry fixtures and fittings including for example wash basins, shelving and pictures.
10.2 Proprietary partitions
A large number of gypsum plasterboard lined partitions have been developed using proprietary systems. As a general guideline for the selection of a suitable partition system, the designer or other specifier should follow the recommendations of BS 5234.
In many cases, basic partition constructions have either been modified or embellished by plastics or metal trims in order to upgrade the appearance, but it does not always follow that the properties remain the same. In such instances, the designer should ensure that the claims being made for the system have been substantiated. Similarly the ability of a relocatable partition system to achieve the minimum specified performance levels when reassembled should be examined prior to selection.
10.3 Trueness of partitions
Deviations of completed partitions should be within the tolerances given in 9.2 to 9.7.
When other components are applied onto or immediately adjacent to the partition surface, e.g. ceiling/wall junctions, rigid skirtings, architraves and worktops. the use of an intermediary component. e.g. shadow batten or foam strip, should be considered.
NOTE. These tolerances do not include residual deflections resulting from, for example, heavy fittings.
The installation of services within the partitions and door frames, access panels, noggins, etc. may have an effect on the final construction line and perpendicular finish. Particular attention should be paid to the following items.
(a) The degree and multiplicity of services resulting in cutting away of the main metal framing within the partition to the extent of impairing the stability requirements of the partition.
(b) Size and intensity of perforations through the partition, e.g. door openings, preplumbed panels, glazed screens, etc.
heating to be provided, provision of adequate ventilation, the permeability of the structure and its components. Every effort should be made to avoid cold bridging.
19 Water vapour checks
Dry lining elements may need to have a vapour check to resist the flow of moist air, either as a part of the lining or as a separate membrane. Care should be taken at the design stage to achieve the required standard of performance for the vapour check. Reference should be made to BS 5250 regarding the need for vapour checks and their positioning.
20 Sound insulation
Sound insulation performance requirements of various parts of the building are the responsibility of the designer. If optimum sound insulation performance is to be achieved, it is important that the adjoining elements offer similar sound insulation performance. The dry lining systems should be assembled in accordance with the specification, ensuring that no airpaths exist, particularly at perimeters. In all dwellings where a wall or floor separates one dwelling from another part of the same building, the sound insulation requirements are prescribed by the Building Regulations 1985.
Where existing separating walls require upgrading, an independent frame should be erected and fixed at the ceiling and floor only. Glass or rock fibre mat not less than 50 mm thick should be inserted between framing members. The frame should be lined with at least two layers of 12.5 mm wallboard, joints staggered, jointed and all perimeters sealed.
Another means of improving sound insulation which can be applied to both new and existing masonry walls is the use of mineral fibre thermal laminates. The laminates, which should be fixed in accordance with 37.2.2, can be applied to one or both sides of the separating walls, depending upon the improvement required, and to the flanking walls.
21 Fire protection
Plasterboard complying with BS 1230: Part 1 is required to have a class 1 surface spread of flame when tiisted in accordance with BS 476 : Part 7 and fire propagation indices. / of not more than 12, and i of not more than 6 when tested in accordance with BS 476 : Part 6. As a result, both surfaces of plasterboard can be designated class 0 in accordance with the requirements of the Building Regulations 1985.
The Building Regulations 1985 and the Building (Inner London) Regulations 1985 through the provisions of Approved Document B also permit plasterboard to be designated a ‘material of limited combustibility’ allowing it to be used as a lining material and to contribute to fire resistance of elements of structure in buildings without restriction.