Home Renovation and Repairs:

Introduction to Loadbearing and Non-Loadbearing Walls, Types of Construction


HOUSE CONSTRUCTION

The illustrations shown on this page demonstrate the most common types of house structure. Variations to these basic categories often arise from architectural innovation, using new materials or using established materials in different ways. While wood frame walls are most common across the US, concrete and steel, for instance, are often used in hurricane-prone regions. Details for identification, construction, or repair of individual elements can be found in the relevant subsections.

LOADBEARING AND NON-LOADBEARING WALLS

The walls in any house can be divided into loadbearing or non-loadbearing. Loadbearing walls, as well as supporting their own weight, carry some of the load of other parts of the building, such as the roof and floors. Non-loadbearing walls support only their own weight, and aren't structural components of the house. Always assume that all exterior walls are loadbearing (even though, in the majority of cases, it's only the internal leaf of a cavity wall that's loadbearing). It can be difficult to identify the other loadbearing walls in a house, but establishing whether a particular wall is loadbearing or not is vital when planning renovation work. The subject is discussed in more detail here.


Above: Basic features of a house: Loadbearing walls transmit the weight of the roof and floors to the ground, while non-loadbearing walls act only as partitions. Foundations spread weight. Within these basic areas of construction there are many variations according to architectural preference and need.

TYPES OF CONSTRUCTION

Three main types of roof, four types of wall, and four types of foundation are shown here. They may be used in any combination so different foundations, walls, and roofs can appear together.

Types of Foundation

Foundations are the supportive structures on which all houses are built. The type used depends on a property’s age, local codes, and the type of ground on which it stands.

Crawlspace and foundation
Above: Foundation wall encloses a Crawlspace: A crawlspace elevates the living space off of the ground, which is beneficial in termite-prone or damp regions. It allows a place and easy access for ductwork and pipes. It is less expensive than a full basement.

Basement
Above: Basement: Basements are usually built on a concrete slab, and a basement is actually a taller version of a slab. A footing is poured and foundation walls are constructed of poured concrete. Or a concrete block can be set on top.

Slab
Above: Slab: A concrete pad, reinforced with steel, covers the area on which the house sits. In some cases the edges of the slab, directly below the exterior walls, will be thicker than the rest of the slab. Modern slab foundations are well insulated.


Above: Pile and Girder: The walls are supported by a column of reinforced concrete, or steel, drilled into the ground. The depth and frequency of beams depend very much on the type of ground below the building, and the building size. Piles may also be required for internal loadbearing walls. Note: Ground level, Pile and Girder.

Types of Wall

The four main types of house construction are generally defined by the way in which the exterior walls have been built. Much more detail about the many variations on these basic categories can be found over the next few pages.


Traditional solid masonry: Older houses tend to have solid exterior walls. Internal loadbearing walls are usually also masonry, but may be wood. Ground floors may be concrete or suspended wood, and very old properties may have traditional floor coverings such as flagstones laid directly on a soil base. Upper floors are usually constructed of wood. Note: Solid, double-skin wall. Older natural stone walls may be much thicker.


Wood: Exterior walls are constructed of wood, and clad in vinyl, masonry, or wood. If the cladding is masonry, metal ties attach it to the internal wall face. Interior walls, whether loadbearing or not, are wood. Upper floors are wood, but the ground floor may be wood or concrete. Note: Wood studs create the house framework.


Modern solid masonry: Some newer houses have solid exterior walls, often built with different materials to their traditional counterparts. Internal walls may be wood or masonry, or there may be some of each. Floors, on all levels, may be concrete or wood. Note: Modern, thermally efficient blocks create solid wall structure.


Masonry with cavity: Exterior walls have an inner and an outer face, held together by metal ties with a cavity between them. They may be made of the same or different materials. Interior walls and floors may be masonry or wood. Note: Interior and exterior wall faces may be made of different materials.

Types of Roof

Most roofs are angled to divert rainwater away from a house. The internal supporting frame is usually constructed of wood studs. The intersection between separate pitched roofs is achieved by forming valleys between each structure. Pitched roofs are commonly covered in asphalt, although other roofing materials may be used. Flat roofs are uncommon and are never exactly flat, as there needs to be a slope to shed water. Valleys require some form of flashing to create a waterproof seam.

Gable roof
Gable: The gable roof is characterized by the triangular wall shape formed where the pitched roof surfaces meet along an apex known as a ridge. This design creates a greater attic area than a comparable hipped roof design. Note: Ridge, Valley.

Hip roof
Hip: On a hipped roof, the gable is effectively cut back at ridge level to provide a triangular sloping roof. The angled ridge that joins this section with the main roof is called a hip.

Flat
Flat: A flat roof looks level, but has a slight pitch to allow water to run off the surface. This design is often used on ground-floor extensions, but may form the main roof structure for some houses.

Thursday, January 26, 2017 19:52 PST

Roof is supported by exterior walls but may also be supported by interior loadbearing walls