Pro Clima, established in the 1980s within the German ecological building movement, provides building membrane solutions that maintain dry, healthy building fabrics without relying on chemical treatments, even for moisture-sensitive materials such as Radiata Pine.

In Australia and New Zealand, timber is often chemically treated to enhance durability against moisture and insect attack. Pro Clima promotes climate-appropriate design and construction techniques, combined with its Weather-Resistive and Intelligent Air Barriers, to control moisture and humidity within construction systems, preventing mould and decay without chemical treatments.

Drained and ventilated cavities act as water drainage pathways but can experience elevated humidity. Highly ventilated cavities, as specified in Pro Clima technical guidance, are recommended to maintain healthy conditions. Reduced ventilation, such as that meeting only NCC 2025 or NZBC minimums, may increase cavity humidity. For roof systems, standard or enhanced ventilation per Pro Clima guidance reduces average humidity in battened cavities. Cladding type and colour also affect cavity moisture.

Where cavity humidity raises concerns for timber rot, treated battens (CCA or LOSP) or non-chemical alternatives, such as hardwood, may be used. When using SOLITEX products with LOSP-treated timber, unstack and allow a minimum of one week on-site for the solvent to evaporate before installing battens over the membranes.

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