04/29/2026
Compatibility and materiality: what happens when things just don’t "stick"?
We recently encountered a site-side challenge where a high performance sub-slab v***r barrier refused to adhere to foundation walls that had been treated with a fluid-applied air barrier. On paper, these products were technically compatible. In reality, the construction site had other plans.
We brought in the product reps for both systems, attempted heavier-duty "claw-type" tapes, and re-prepped the surfaces, but we still couldn't get the bond we needed for a passive-house level seal.
The solution? We pivoted to a tried-and-true mechanical termination bar detail to fasten and seal the top edge of the membranes to the vertical surface.
This is the reality of high performance building: you can have the best data sheets in the world, the best details and the best intentions, but you always need a "Plan B" that accounts for the variability of the field. Sometimes the simplest mechanical solution is the most resilient one.
