Over-cladding systems
Overcladding system is often the most logical solution to achieve a range of improvements to the thermal performance and external façade of the building, especially for high rise buildings. It is best suited to use in a comprehensive rehabilitation scheme, including window and door replacement and the installation of new heating and ventilation systems.
Overcladding system in its generic form is a composite system consisting of three key components:
- Insulant
- Fixing or framework
· Mechanical fixing
· Chemical fixing
· Mechanical and chemical fixing
- Finish
· Wet render
· Dry cladding

Overcladding system is appropriate for refurbishment projects when

· The external walls are poorly insulated
· The external walls are deteriorating or insufficiently weather tight, leading to damp, draught and heat losses.
· Wall cavities are bridged or blocked, limiting the possibility for cavity fill insulation.
· The use of internal lining insulation would be too disruptive, would alter critical internal dimensions or make room sizes too small.

General factors to consider in application of overcladding systems:

· overcladding system will involve alteration in various details of the building such as at windows, doors and where services punctuate the external envelope;
· the planning authority should be consulted for all overcladding system refurbishment projects. Overcladding system may not be appropriate where its application may alter the appearance of a sensitive or historic building.

An overview of existing overcladding (wet render, dry render and bespoke) systems available and some suggestion for selecting overcladding systems are given, including a list of advantages and drawbacks.