Blockwork and Hebel Brick, are interesting products, and they provide so many features in construction, but can these types of walls be relied upon for airtightness? In this video we smoke test and pressure testing, blockwork and hebel brick, and also try some coatings in order to create an area barrier. Note that all test results are for this sample product specifically, and the air leakage rate due to the small sample is indicative only.
Other manufacturers blockwork products, can vary significantly due to different densities, porosity and surface qualities. The worst publically documented report on leaky blockwork is available below. An independent test (report number 109848) performed by HRS Services Ltd (UK , now part of Stroma Group) in 2011 demonstrated uncoated standard cellular blocks has the air leakage rate greater than 80m³/h/m². https://www.airtightpaint.co.uk/app/d…
Great information on the masonry wall airtightness. I had the same issue when I installed 8 mm OSB as an air leakage control barrier. It leaked like a sieve. I resolved it with 3 thick coats of low voc plasterboard sealer. This sealed the product with minimal compromise to the vapour permeability.