An independent analysis of the thermal characteristics of Irish concrete hollow blocks and hollow block wall upgrades and a discussion on hollow block design

Hollow block walls, whether originally built with external render and internal plaster, or more recently with external render and insulated drylining, represent the most common form of wall construction in Leinster over the last 50 years (see image in Figure 8). In terms of vapour movement, air movement and thermal performance it is also one of the least understood forms of construction practiced in Ireland. This technical paper and two articles by the same author published by Construct Ireland in February and May 2009 (Issues 6 & 7, Vol. 4) form a concerted effort to rectify this knowledge deficit. It is our wish that together these information sources will enable homeowners, architects and builders to deal better with the legacy of this problematic form of construction. The current situation, particularly in relation to filling of cavities, where installers do not understand the full picture (i.e. the consequences for thermal performance, weather tightness and health) and are thus advising values that are unachievable or incorrectly estimated, must be controlled and misrepresentation stopped for the sake of consumers.