Ceiling strapping spacing recommendation to hold up 22″ of blown-in cellulose
Myrtleboone
| Posted in General Questions on
I am in the process of trying to determine how much strapping spacing is needed on a ceiling to support 22″ of blown-in cellulose above it. The strapping is 1×4 pine and I plan on spacing 16″ OC whixh makes the space between supports of 12″. The strapping is holding 6 mil poly up against the bottom chord of the truss. There will be some ballooning of poly downward in those squares between truss and strapping. 5/8″ Sheetrock will be used up against strapping to finish. Thanks in advance.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
"We have blown very high R-values, up to R-100, and never had any issues with the ceiling sagging."
see here: https://www.greenbuildingadvisor.com/community/forum/green-building-techniques/25580/58-drywall-sufficient-support-r-60-cellulose-ceiling
Mathew… I have dense packed cellulose, R60 between 24" OC rafters, cross strapped with dry 1 X3" pine purlins 16" OC, with ½" generic Home Depot (called low sag) drywall. We used high quality, drywall PVC glue (not the green stuff and not liquid nails) and screws. There is no visible sag or rounding.
Correction ... polyurethane glue, not PVC glue.