You can’t control who moves in next door and for some, even the faint whiff of tobacco smoke wafting through a bedroom window is too much. Imagine smelling your neighbour’s cooking odours or cigarette smoke daily and it coming through the wall. This scenario plays out all over the city with frustrated residents and new mothers in particular.
We conduct countless building investigations involving smell contaminants migrating through shared floors and walls. Patterns have emerged from our findings. Namely, in colder months, holes or penetrations through shared assemblies allow air to carry the offending odour from the source to the target. The solution is usually the same; seal it up, test the seal and if tight close it up. The irony; it would be so easy and affordable to seal those penetrations during the construction phase. It begs the question; why isn’t air tightness testing in multiunit residential mandatory?
For low rise residential houses, the trick is to assemble party walls as air tight as possible. Yet, there’s nothing in the Ontario Building Code that requires a continuous air barrier system for Part 9 buildings on shared partition walls (the focus is on controlling fire spread). For semi-detached homes, most of the troubles occur in floor cavity areas; but, in stacked town homes, the complexity grows as staircases and walls penetrate the separation between the units making remediation more invasive and expensive.
For high rises, we’ve had instances of contamination coming through the gap between the slab and the curtain wall and even from the pressurised hall; however, most of the contamination connections identified in our investigative work involves missed or failed fire seals through sleeves in the floor slabs.
Again, all of these contamination issues between units could be significantly curtailed by simple compartmentalisation testing of separate units with independant heat recovery ventilation for each unit. One example of this kind of testing is LEED’s Environmental Tobacco Smoke (ETS) testing where 10 percent of completed units are randomly tested and within the maximum allowable air leakage threshold. This is one simple way to test the integrity of the apartment unit or “compartment” for higher resistance to fire, smoke and other smelly contaminants. In some cases, a visual inspection of the penetrations catches the problem, but only a stress test like a blower door test, which quantifies the air leakage rate in the unit, while using visible tracer smoke positively identifies a breach or potential source of contaminant.
It’s not just unwelcome odours. We had a case where a client had bedbugs crawling through his 100-year-old semi’s party wall ravaging the family’s five-year-old daughter. Though the client had paid to fumigate and treat their neighbour’s home twice, the rental next door to a large family living in squalid conditions couldn’t kick the pests even with repeated treatments. In the end the masonry wall had to be stripped back and a liquid-applied air barrier was painstakingly applied to the assembly. The good news, this retrofit resulted in a quieter house and one free of the neighbour’s other habits: strong cooking and second hand tobacco odours.