Low-rise Apartments Development
Low-rise apartment buildings cover a wide range of housing types. Due to the relatively low construction costs, modern cities have a strong demand for this type of housing. Most low-rise apartment buildings are built by local small and medium contractors and utilize relatively few large machines (most used for earth-moving).
The core function of the foundation of low-rise apartment buildings is to transfer building loads to stable formations. There are two criteria for said stability: first, the soil under the foundation should be able to withstand the applied load and should not exceed about 2.5 cm (1 inch) of settlement; secondly, the settlement of the building should be uniform. It is also important that the foundation is below the frost line. Wet soil swell when frozen, and the repeating freeze-thaw cycles can cause buildings to move up and down, causing possible displacement and damage. The frost line varies with climate and terrain. In cold continental climates, it can be as deep as 1.5 meters (5 feet); in the tropics and some subtropical regions, it is usually 0 meters. The base system of low-rise residential buildings is suitable for light loads; the foundations of low-rise apartments are usually made of concrete with a minimum depth of approximately 30 cm (12 inches). The foundational wall can be constructed from reinforced concrete or masonry, especially concrete blocks. Concrete blocks have a larger standard size than bricks and are hollow, forming a vertical planar grid.
In smaller low-rise apartment buildings, traditional materials such as wood and masonry are still the most used materials. North America has a rich softwood forest, and wooden frames are typically 2 or 4 cm (0.75 or 1.5 inches) thick and are attached tightly by nails and other metals made from hand-operated tools .
The span of the floor joists is typically about 3.6 meters (12 feet), which is the common maximum length of available wood. The floor may require intermediate support in the form of an internal foundation wall, or, if there is a basement, an intermediate wooden beam or steel beam supported by the foundation wall and columns. For longer spans, floor trusses can be fabricated in which the components are joined by pegs, stapled plywood gussets, or wood strings and diagonal metal web members. At the top of the joist is the nail ply subfloor, which forms the deck and provides lateral stability to the floor plan.
The walls are covered with plywood or particle board to provide a surface that connects the outer cladding and lateral stability against the wind. Plywood and particle boards are manufactured using standard sized panels. The plywood is made of thin wood, cut from the logs and mixed with the wood grain, extending vertically in adjacent layers. Particle boards consist of fine wood chips mixed together in an adhesive substrate and allows for hardening under pressure.
Since most roofing materials used in buildings are not completely waterproof, the roof must have a sloped surface to drain water quickly. Ramps are created in two ways. The conventional method involves using a joist similar to a floor structure across the outer wall. The tweezers are nailed to the end of each joist, and meet at the central ridge to form a triangular attic space. In cases where there is no need for for attic space, crossing the roof using a triangular truss with internal web members is more economical. These roof trusses are usually made of narrow wood joined by nails, glue, or metal connectors, and are usually prefabricated in the workshop. The plywood or particle board sheath is then nailed to the surface of the roof to support the roof and provide lateral stability, making the entire frame a rigid cabinet.
Light wood frames are flammable, but evacuation in smaller single or double-story buildings evacuation in the event of a fire is relatively easy, so construction laws allow the use of these frames.
Masonry walls are also commonly used in such buildings, but are mainly used in multi-layered structures. They provide greater load carrying capacity and better resistance to fire. Brick-concrete blocks are the main materials and are widely favored because of the aesthetic appearance of the masonry. Hollow composite walls are common. The heat flow rate of the hollow walls is 50% of the solid walls.
The frame system for low-rise apartments varies. For roofs, traditional shingles or even more common felt asphalt shingles are used. Semi-cylindrical clay tiles and upright seam metal roofs are also common. Rain from the roof is usually guided by metal gutters to external pipes, which are discharged into underground drains.
The frame systems for low-rise apartments vary. Traditional wooden planks are used for traditional wood frames. Brick stone finishes are also appropriate; they are usually fixed to the wood with metal fasteners. Cement gypsum or plaster is another traditional material used to seal wood and masonry structures, and its semi-fluid application allows for great plasticity. The latest trend is to place very thin synthetic resins directly on the surface of a rigid plastic foam insulation.
Most low-rise apartment buildings have a limited number of transparent openings because of traditional privacy requirements and the relatively high costs of windows compared to opaque walls. Conventional window wood frames are typically covered with die-cast vinyl or aluminum cladding, and frames made entirely of die-cast aluminum are also common. Residential windows are a major form of ventilation with a variety of moving parts: sliding or double-hung windows are still the most popular forms, but hinged windows – including sashes, hoppers, and awnings, are also relatively common.