Building Construction 13 Dr Nabil El-Sawalhi Associate professor Engineering Projects Management

Doors A door is a solid barrier that is fixed to a frame in an opening in a wall to hinge, pivot or slide open (or to close). The door opening (the doorway) allows access and egress from buildings and between rooms.

Functional requirements ❑ Safe means of access and egress ❑ The functional requirements of a door, when closed, are: ❑ Security, prevention of unauthorised entry ❑ Privacy ❑ Strength and stability ❑ Resistance to weather ❑ Durability and freedom from maintenance ❑ Fire safety ❑ Resistance to the passage of heat ❑ Resistance to the passage of sound ❑ Airtightness ❑ Aesthetics

Safe means of access and egress The standard width and height of 762 and 1981 mm To allow comfortable access for people with disabilities, the minimum clear opening for a single door should be 800 mm. Clear opening widths can be achieved by selecting a 1000 mm single-leaf door set (850 mm clear opening width of leaf) or a 1.8 m double-leaf door set (810 mm clear opening width of each).

Security External doors should be designed so as to provide a secure barrier against unauthorized entry. Solid hinges, locks and key bolts to a solidly framed door in a soundly fixed solid frame are the best security against forced entry. Privacy Doors should serve to maintain visual privacy inside rooms to the same extent that the enclosing walls or partitions do. For acoustic privacy, doors should offer the same reduction in sound as the surrounding walls or partitions

Strength, stability and durability A door assembly should be strong enough to sustain the conditions of use without undue damage.

 Door types Doors are supported in openings (doorways) on hinges as side hung, on pivots as double swing and on tracks as sliding or folding doors as illustrated in Figure 8.4. Doors usually open into the room of which they are part of the enclosure.

❑ Hinged, single-swing, side-hung doors are for frequent use between rooms and between rooms and corridors or landings. ❑ Hinged and pivoted side-hung, double-swing doors are for frequent use along corridors to accommodate two-way foot traffic. ❑ Sliding and sliding folding doors hung on overhead track are for occasional use in openings between rooms to convert single rooms into larger double rooms. ❑ Combinations of single-swing, double-swing and sliding and folding doors may be used for specific purposes

Timber door classification Timber doors may be classified as (Figure 8.5): ❑ Paneled doors ❑ Glazed doors ❑ Flush doors ❑ Match-boarded doors

The traditional door is formed from solid softwood or hardwood members framed around panels. This construction has been in use for centuries with little modification other than in changes in jointing techniques due to machine assembly and the use of substitute materials for wood.

Paneled doors Paneled doors are framed with stiles and rails around a panel or panels of wood or plywood. Because the door is hinged on one side to open, it tends to sink on the lock stile. The stiles and rails have to be joined to resist the tendency of the door to sink, and the two types of joint used are a mortice and tenon joint (Figure 8.6) and a dowelled joint (see Figure 8.8).

Glueing, wedging and cramping The word cramp describes the operation of forcing the tenons tightly into mortices. The members of the door are cramped together with metal cramps, which bind the members together until the glue in the joints has hardened. Before the tenons are fitted into the mortices, both tenon and mortice are coated with glue

Panelled doors The traditional panelled door was constructed with four or six panels with central framing members, termed muntins, tenoned to rails as illustrated in Figure 8.12. The advantage of this arrangement is that the width of the panels is limited to reduce the possibility of shrinkage cracks and the shape of the panels emphasises the verticality of the door.

Flush doors A variety of flush doors are manufactured with plain flush faces both sides and fibreboard facings press-moulded, often with comparatively shallow sinkings, to resemble the appearance of panelled doors

 Hardware Hardware is the general term used for the hinges, locks, bolts, latches and handles for a door. Ironmongery was a term used when most of these were made of iron or steel. Hinges Pressed steel-butt hinge Pressed steel-butt hinges are the cheapest and most commonly used hinges

Latches and locks The word latch is used to describe any wood or metal device that is attached to a door or window to keep it closed. Mortice lock The mechanism most used today for doors is the mortice lock, so called because the metal case containing the operating parts is set into a mortice cut in the door. Locks for external doors and internal doors, where security is a consideration, consist of a latch bolt and a lock bolt.

Windows A window is an opening formed in a wall or roof primarily to admit daylight through some transparent or translucent material. Windows also serve an important function in providing controlled natural ventilation to buildings and make a major contribution to the visual appearance of buildings.

Functional requirements The primary function of a window is to: ❑ Admit daylight and provide a view Additional performance requirements include: ❑ Safety – comply with relevant health and safety legislation including the Construction Design and Management (CDM) Regulations ❑ Strength, stability and airtightness ❑ Fire safety ❑ Provision of ventilation ❑ Resistance to the passage of heat ❑ Resistance to the passage of sound ❑ Safety ❑ Security ❑ Aesthetics ❑ Durability and freedom from maintenance

Window types Hinged Pivoted Sliding Side hung Top hung Bottom hung Pivoted Horizontally pivoted Vertically pivoted Louvre Sliding Vertically sliding Horizontally sliding Composite action Side-hung projected Top-hung projected Bottom-hung projected Sliding folding

Aluminum casement windows The majority of aluminum windows that are made today are of sections extruded from aluminum alloy in a wide range of channel and box sections with grooves for lips for weather-stripping and double-glazing. The sections are mitre cut and mechanically cleated or screwed at joints, which are sealed against entry of water as illustrated in Figure 7.52 Aluminum window sections are usually finished with anodised, polyester powder or liquid organic coatings as protection against oxidisation and as a decorative coating that can be easily cleaned.

A disadvantage of aluminum as a window material is that it is a good conductor of heat and a potential thermal bridge. The aluminum frame is secured to the surrounding wall by aluminum lugs that clip to the back of the frame at centers of up to 600 mm and also adjacent to hinges and fasteners, with the lugs screwed to plugs in the wall.

Sealants Sealants used for sealing perimeter joints around window frames are classed as plastoelastic, elastoplastic or elastic. Plastoelastic sealants, which have some elastic property, remain predominantly plastic and can be moulded. ❑ Elastoplastic sealants, which develop predominantly elastic properties as they cure, will return to their former shape when stress is removed and also retain some plastic property when stressed over long periods. ❑ Elastic sealants will, after curing, have predominantly elastic properties in that they will continue to resume their former shape once stress is removed, during the anticipated useful life of the material.

Acrylic, polysulphide, polyurethane and silicone The materials that may be used for perimeter sealing around window and door frames are acrylic, polysulphide, polyurethane and silicone. Of these, acrylic is classed as plastoelastic, polysulphide as elastoplastic, and polyurethane and silicone as elastic. In general the plastoelastic material is easier to use because of its predominantly plastic nature, but it will not form as tough and elastic a surface as elastoplastic materials that have some plastic property. The elastic materials need some experience and skill in use for successful application.

Window sealant functions As the prime function of a sealant to perimeter gaps around window frames in traditional walling is as a filler to exclude wind and rain, it should adhere strongly to enclosing surfaces, be resistant to the scouring action of weather and sufficiently elastic to accommodate small thermal movements for the anticipated life of the material. The expected useful life of sealants, after which they should be renewed, is up to 15 years for acrylic and up to 20 years for polysulphide, polyurethane and silicone.

To ensure maximum adhesion, the surfaces onto which a sealant is run should be clean, dry and free from dust, dirt and grease. Sealants are usually run into joints from a gun operated by hand pressure or air pump and, for appearance, the sealant should not be too obvious.

 Glass and glazing Glass is made by heating soda, lime and silica (sand) to a temperature at which they melt and fuse. Molten glass is drawn, cast, rolled or run on to a bed of molten tin to form flat glass. Glass may be classified into three groups; annealed flat glasses, processed flat glasses or miscellaneous glasses.