The Cav-Form Story

Cav-Form, as with many innovations, was borne out of necessity. The increasingly common client brief involved maximising internal floor space, without compromising the integrity of the wall or the quality of the build. Of course, it also needed to be compliant with building regulations. In combination, these requirements provided a challenge to the traditional method of construction. The backing blocks ordinarily used within the construction of a random stone wall are both sizeable and numerous, rendering them incompatible with the goal of maximising internal floor space. Clearly, an alternative solution to the blocks was necessary and one that would provide the same functionality without using up vital space. The development of the Cav-Form system, elements of which can be seen in more detail below, has provided this much needed advancement in construction. A client brief, which once appeared to be so ambitious, no longer seems unachievable — in fact, it can be achieved in a more cost effective, practical and environmentally beneficial manner.

The Cav-Form System

Cavity spacer

The cavity-forming spacer attaches easily to the most proprietary masonary ties and fits the Cullen range of timber frame wall ties to create a perfectly uniform, clean, dry space. It helps keep the insulation batts pressed firmly against the inner leaf.

Retaining clip

This unique Cav-Form clip fits in seconds and holds the board in place permanently. It attaches to the cavity tie to secure the backing board and hold the system in place during construction. This also helps keep the insulation batts securely positioned against the inner leaf.

Waterproof backing board

Manufactured from recyclable co-polymer polypropylene, the stong corrugated board replaces concrete backing bloacks a a rate of 1 sheet of Cav-Form to 9 concrete blocks. Supplied in 2000mm x 450mm sheets, the board is light to handle and easy to install. In fact, unlike 9 concrete blocks, you can lift a sheet of Cav-Form between your finger and thumb. The board is placed in front of the Cavity Forming Spacer in between rows of cavity ties. It protects the cavity from mortar and debris during constuctions and from water ingress after construction.

Fitted to masonary

Stone, brick, concrete block and timber are all absorbent materials and draw moisture (including rainwater and water vapour from the atmosphere) into the outer leaf. It is imperative that this moisture does not travel any further. The cavity is the essential moisture barrier, preventing the inner leaf from becoming damp. Any mortar or debris dropped into the cavity during construction can seriously affect its function by settling on the wall ties or collecting at the base of the cavity, resulting in moisture and cold bridging. The system also provides added protection to properties exposed to driven rain.