board are popular as bases for tiling in kitchens or in wet areas like bathrooms. Galvanized sheet fixed to wooden or steel members are mostly adopted in works of temporary character. Plain or reinforced partition walls may also be constructed from concrete, including pre-cast concrete blocks. Metal framed partitioning is also available. This partition consists of track (used primarily at the base and head of the partition) and studs (vertical sections fixed into the track typically spaced at 24", 16", or at 12"). Internal wall partitions, also known as office partitioning, are usually made of plasterboard (drywall) or varieties of glass. Toughened glass is a common option, as low-iron glass (better known as opti-white glass) increases light and solar heat transmission. Wall partitions are constructed using beads and tracking that is either hung from the ceiling or fixed into the ground. The panels are inserted into the tracking and fixed. Some wall partition variations specify their fire resistance and acoustic performance rating. Movable partitions Movable partitions are walls that open to join two or more rooms into one large floor area. These include: Sliding—a series of panels that slide in tracks fixed to the floor and ceiling, similar sliding doors Sliding and folding doors —similar to sliding folding doors, these are good for smaller spans Folding partition walls - a series of interlocking panels suspended from an overhead track that when extended provide an acoustical separation, and when retracted stack against a wall, ceiling, closet, or ceiling pocket. Screens—usually constructed of a metal or timber frame fixed with plywood and chipboard and supported with legs for free standing and easy movement Pipe and drape—fixed or telescopic uprights and horizontals provide a ground supported drape system with removable panels. Party wall Party walls are walls that separate buildings or units within a building. They provide fire resistance and sound resistance between occupants in a building. The minimum fire resistance and sound resistance required for the party wall is determined by a building code and may be modified to suit a variety of situations. Ownership of such walls can become a legal issue. It is not a load-bearing wall and may be owned by different people. Infill wall An infill wall is the supported wall that closes the perimeter of a building constructed with a three-dimensional framework structure. Fire wall Fire walls resist spread of fire within or sometimes between structures to