Most houses are built from a combination of bricks, concrete blocks and timber on a solid base known as the foundations. The construction of the walls depends on whether they’re external or internal, and whether they’re load-bearing or non-load-bearing.The external walls of a house are all load-bearing, as they support the weight of the roof, floors and internal walls.
Solid External Walls
External walls can be of solid or cavity (hollow) construction. The solid walls are usually made from concrete blocks. This type of wall generally gives good sound insulation, but doesn’t retain heat very efficiently.
Cavity External Walls
Most modern houses have external walls constructed with a cavity in the middle. Typically, the leaves (walls) are each about 100mm thick, separated by a gap of at least 50mm, and tied together with metal wall ties to make them stable.
Cavity walls are built from bricks, concrete blocks or timber framing, or a combination of these. They’re more effective than solid walls at preventing moisture penetration and heat loss. Uninsulated cavity brick walls can also have insulating material blown between them that make your house much cozier and more energy-efficient.
Identifying cracks in external walls
There are two main types of crack that can appear in your masonry walls:
Vertical
Stepped
Vertical cracks in external walls usually occur in foundation walls when there is insufficient support below. The main reason for this lack of support is when the soil beneath the foundation has not been properly compacted and compresses or even washes away.
Stepped cracks in walls mostly follow mortar joints and are most common near the corners of building. They usually occur through wall movement related to foundation movement including subsidence.
Why Are My Walls Cracked?
Cracks in walls can occur for a number of reasons. With new build houses. Cracks can appear as the house ‘settles’ –settlement of soil due to weight of the building.
In older properties small cracks can be fairly common as building materials shrink overtime. We have divided the main causes of cracked walls into structural and environmental factors.
Structural Factors
1.Subsidence
2.Structural Failure
3.Corrosion
4.Mining
5.Heave
Environmental Factors
1.Thermal Expansion
2.Leaks
3.Freezing
4.Decay of Materials
5.Vibration
Healthy Homes with its expert and experienced technical team can assess and repair external walls. Give us a call today on 1800-419-4647.
