Cavity walls consist of two masonry walls separated by an air space or cavity, which allows moisture to escape via weep holes spaced 1 meter apart along the base of their outer wall.
Fill the cavity with insulation materials such as foam or mineral wool.
Moisture Control
As cavity walls create a gap between their outer and inner walls, they help prevent dampness from entering from the exterior into the house and also offer sound and thermal insulation benefits.
However, the gaps between two masonry walls can be vulnerable to condensation. When moisture vapor condenses on cold surfaces within the cavity and forms condensation droplets, wood rot and mold may result.
To address this problem, a vapour control layer or barrier is commonly installed between cavity insulation and inner masonry skin to help stop warm air reaching dew point and leading to condensation. This helps keep warm air from reaching dewpoint and leading to additional condensation issues.
At all stages of construction, it is also vitally important that cavities remain free from debris such as dirt or mortar droppings which could compromise their performance and necessitates active supervision of wall building activities. Furthermore, wall ties should be regularly checked and cleaned of any build-up to avoid moisture entering through these points.
Sound Insulation
Cavity wall insulation is an effective way to soundproof your home and reduce noise pollution from neighbors, stereos, televisions and traffic noise pollution – helping alleviate stress levels as well as sleep difficulties and anxiety issues.
An effective sound barrier works by redirecting soundwaves away from your house, similar to heat bouncing off walls. It may also reduce noise that enters through windows and doors.
A cavity wall uses water-repellent insulation materials such as foam or mineral wool to seal its space between two leaves, and connect them together using metal ties called wall ties.
Cavity walls require skilled labors and masons who possess specific expertise, as well as standard supervision during their creation. Once built, however, these insulating walls offer greater insulation against driving rain, heat and cold fluctuations and dampness while being more cost-effective than solid walls with less maintenance requirements required to keep dampness at bay. They can also withstand pressure loads more effectively due to being less rigid structures.
Thermal Insulation
Cavity wall insulation is an effective way to minimise heat loss in properties, especially those located in cold regions. Furthermore, it makes soundproofing properties much simpler; but choosing the appropriate material depends on both your property type and climate conditions.
A cavity wall consists of an outer brick layer and an inner brick layer joined together using metal wall ties that connect their bricks on both the external and internal leaves, typically laid out in stretcher bond but other designs may also be possible.
These walls are ideal for exterior walls as they help prevent moisture from permeating through from the exterior to the interior, unlike solid walls which can absorb it and lead to damp problems. Furthermore, cavity walls offer thermal and sound insulation benefits; however they require highly skilled labor and regular supervision during construction as well as ventilation to keep air flowing properly through.
Structural Strength
Cavity walls are popularly constructed as non-load bearing external walls; however, they can also be used as load-bearing structures. Their outer leaf typically comprises half brick thickness and is joined to its counterpart using wall ties embedded into both leaves of the cavity wall’s mortar joints.
The gap between two walls allows moisture to escape without penetrating into the inner wall, thus eliminating one of the primary drawbacks of solid walls. Unfortunately, sediment such as dirt or flaking mortar may collect in this cavity, negating some of its benefits.
Special requirements have been imposed for the construction of cavity walls in frame-type buildings. It is required that any mortar used to construct such walls possess high strength to resist out-of-plane forces and that its ties connect two leaves strong enough to transfer tensile loads.