Treating Weak Points in Building Airtightness

The pencil test: Trace the interior line of your building on a floor plan or section drawing. Wherever the line breaks — that's where air leaks. Here are the top 3 weak points and how to fix them: 1️⃣ Window & door perimeters Quality windows are airtight — but the joints between frames and walls are not. Seal both sides: ? Interior → vapor-impermeable membrane (blocks indoor moisture from entering walls) ? Exterior → vapor-permeable membrane (lets trapped moisture escape) 2️⃣ Wall penetrations (pipes, ducts) Gaps between pipes and walls need the same treatment: vapor-impermeable on the inside, vapor-permeable on the outside. 3️⃣ Different material junctions Masonry-to-concrete, steel-to-concrete — these joints need airtight membrane applied before plastering. Other weak spots include tie-bolt holes in shear walls, kitchen exhaust shafts, and more. Each project has its own — we'll cover them case by case. ? Watch the video to learn more.