The external envelope of a building provides weather protection and security. However, the internal space becomes useless unless it is divided into meaningful compartments or rooms.
The method of dividing the space is using internal walls. In some offices, this is achieved by the planned positioning of cupboards, pot plants, and movable screens.
Internal walls may sometimes carry structural loads or they may be constructed as non-load bearing walls.
Internal non-load bearing walls or partitions are built in bricks or cement blocks. But to reduce cost, provide lightweight, and provide mobility, they may be built using other materials.
The functions of internal walls are:
- Partitioning the internal space
- Provide fire resistance
- Provide insulation, both thermal & sound
- Provide security
- Support fittings, fixtures, and decorations
- Be static or movable
- Accommodate services
Brick and block partition walls
These walls are usually ½ brick thick or 1 brick thick in some cases.
They have to support their self weight, and need not be cavity walls since there is no need for weather resistance.
Where an opening is required in an internal wall for doors or service hatches, they should be built in as the walling proceeds.
Finishes for internal walls depend on the function of the building, the decorative effect required, and the cost.
Common finishes
Plaster work provides a smooth dense joint-less surface for painting and decorating.
Plasterboard sheets 12.7 mm thick called ‘dry lining’ uses 38 x 19 mm battens fixed to the wall vertically at 400mm centers with screws, and the plasterboards are fixed using GI nails. The joints between sheets are reinforced with paper tape, and the joint is filled flush with the surface.
Finally, the surface is finished with a 3.5 mm thick skim coat of plaster.
Plywood, fiberboard, flat asbestos cement sheets, and thin sheets of plywood or hardboard with laminated faces are also used as finishes.
Ceramic, glass, or plastic tiles too can be used as internal wall finishes. In addition to the decorative effect, they give water resistance to walls in bathrooms, kitchens, etc.
The brick walls can also be left uncovered. In this case, the joints may be prepared using coloured mortars or special pointing methods.
Timber partition walls
Timber partitions or Stud partitions consist of a framework supporting ‘dry linings’ material such as plasterboard, plywood, or hardboard.
The framework consists of;
1. Vertical studs spaced at intervals to suit the loads and dimensions of facing boards
2. Horizontal sole plate at the bottom
3. Horizontal head at the top
4. Horizontal noggins fixed between studs to provide lateral support to studs
5. Facing boards that take the wall finishes.
These partition walls have to support their weight and in addition, the impact loads of doors closing/opening, furniture, etc., banging against them.
To get an even surface to the wall, the frame members should be of the same thickness.
The common sizes are 100 x 50 mm, 100 x 38 mm, 75 x 50 mm, and 75 x 38 mm.
Timber walls are much quicker to build than brick or block walls, and are also light-weight.