The drive for energy efficient buildings is leading to improved air tightness, the installation of bulk insulation and a failure to consider the building envelope holistically is leading to roof space and interstitial condensation.
Failure to consider condensation within your roof space and walls can have serious consequences.
“Higher levels of insulation may introduce unforeseen problems where they are incorporated into construction styles which have previously been relatively immune to condensation. This is because insulation, whilst it keeps some surfaces warm, also keeps other surfaces cold.”
A simple example is domestic roof spaces.High levels of ceiling insulation mean that roof spaces are colder as they are not heated to the same extent from below.” (CSIRO, 2001)
Unlike foil and perforated foil products, the high water vapour permeability of the Proctor Roofshield and ProctorWrap breathable membranes allows for the escape of high volumes of vapour from within the building at the same time as restricting the ingress of moisture.
<li>protection against wind-driven rain, snow and dust during construction and for the life the building</li>
<li>highly durable, strong and lightweight textile membranes</li>
<li>quiet when exposed to wind</li>
<li>non corrosive for coastal environments</li>
<li>vapour resistance no greater than 0.26MNs/g</li>
<li>complete range of AS4200.1:1994 compliant products for walls and roofs</li>
<li>a system approach including window surrounds and tapes</li>
|Description||How much vapour can |
pass through 10m²/day?
|How long would it take for 1,000mL|
vapour to pass through 10m²?
| Proctor Roofshield|
|6,500 mL||3 hours + 45 minutes|
| ProctorWrap AT|
|3,100 mL||7 hours + 45 minutes|
|Perforated “breather foil”||120 mL||7 days + 15 hours|
| Perforated “breathable” reflective|
|30 mL||32 days + 1 hour|
Condensation Risk Analysis Service
We use independent software to conduct condensation risk analysis. This software is available for download at www.techlit.co.uk If you purchase this software and need assistance we are happy to share our database of Australian climate data from the Bureau of Meteorology and common material properties.
If you prefer, we offer a free condensation risk analysis available through the Technical Advisory Service of the Dynamic Composite Technologies website. Alternatively please send us send us the following information preferably by e-mail to email@example.com
|Links for background reading or sites referenced in the presentation|
There is a wealth of information on the web about condensation and global sick house/building issues. Just googling “sick building”, “mouldy/ moldy home”, “roof space condensation” will keep you busy for days
|Building Science Information|
One site that is well regarded in the building science community is www.buildingscience.com. There is a lot of free information on this website which although there is a North American slant, is equally relevant to Australia. The following articles make reasonably light reading and go into greater depth, some of the issues raised during the presentation and the Q&A: