Assuming unsealed opening between wall and roof deck was observed on site.
Conditioned air is escaping or outside air is infiltrating around gaps between the building wall and the building roof. In either case heating energy is lost, comfort is reduced (drafts in winter), and the life expectancy of building components is reduced by the uncontrolled migration of air and moisture through the building envelope.
A commercial grade spray-in-place foam should be applied around the entire roof-wall joint of the building / in xxx, where accessible. The foam must be capable of forming an air barrier, and must be installed by a qualified insulating contractor.
The foam must be capable of forming an air barrier and fully sealing the existing gap. It must be installed by a qualified insulating contractor.
Issues and Concerns
This recommendation is in accordance with Measures BE7 and BE8 of the CMHC manual on Energy and Water Efficiency in Multi-Unit Residential Buildings and with Section 6.2 Building Envelope of the ASHRAE Standard on Energy Conservation in Existing Buildings.
The CMHC manual on Energy and Water Efficiency in Multi-Unit Residential Buildings can be found online at www.hwbinc.com/495-1003/introduction.html.
ASHRAE Standard ANSI/ASHRAE/IESNA 100-1995 – Energy Conservation in Existing Buildings is an approved standard of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., the Illuminating Engineering Society of North America and the American National Standards Institute.
Estimate average crack width on site. Determine length of unsealed roof/wall joint. Use ASHRAE crack method for calculations. Sealing will eliminate loss.