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Title: Analysis of Joint Masonry Moisture Content Monitoring

Adding insulation to the interior side of walls of masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw, have known solutions, but wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content & relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100% RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated versus non-insulated joist pockets do not show large differences. South facing joists have safe (10-15%) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-riskmore » situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.« less
  1. Building Science Corporation, Westford, MA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Building Science Corporation, Westford, MA (United States); National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B)
Country of Publication:
United States
Residential; Residential Buildings; BSC; Building America; Masonry; retrofit; insulation retrofit; moisture damage; j oist ends; embedded members; embedded wood members