BRE IP2/05 PDF

Introduction

Interstitial condensation can occur in all types of buildings and cause a range of problems from staining of interior decoration, as the condensate leaks back into the building, to damage to the fabric that can affect structural integrity. Concerns have been expressed about the health implications of the growth of so-called ‘toxic mould' that can occur when condensation persists within structures. Changes in construction, especially the use of more thermal insulation and impermeable claddings and the trend toward offsite manufacture of building elements, may increase these risks.

The recent revision to Part C of the England and Wales Building Regulations^[1], which came into force on 1 December 2004, requires, for the first time, that: ‘The floors, walls and roof of the building shall adequately protect the building and its users from harmful effects caused by...(c) interstitial and surface condensation'. This introduces a new requirement for structures to be assessed for interstitial risks and emphasises the need for appropriate calculation techniques.