Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts
Abstract
?There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such 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 and 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 percent 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 vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15more »
- Publication Date:
- Research Org.:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Org.:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office
- OSTI Identifier:
- 1225940
- Report Number(s):
- NREL/FS-5500-64766; DOE/GO-102015-4738
- DOE Contract Number:
- AC36-08GO28308
- Resource Type:
- Program Document
- Country of Publication:
- United States
- Language:
- English
- Subject:
- Residential; Residential Buildings; BSC; Building America; Masonry; Retrofit; Insulation retrofit; Moisture damage; Joist ends; Embedded members; Embedded wood members
Citation Formats
. Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts. United States: N. p., 2015.
Web.
. Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts. United States.
. 2015.
"Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts". United States. https://www.osti.gov/servlets/purl/1225940.
@article{osti_1225940,
title = {Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts},
author = {},
abstractNote = {?There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such 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 and 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 percent 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 vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15 percent) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk 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.},
doi = {},
url = {https://www.osti.gov/biblio/1225940},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Oct 01 00:00:00 EDT 2015},
month = {Thu Oct 01 00:00:00 EDT 2015}
}