Empirical Masonry Design
Empirical Masonry Design
(OP)
I have a question I'm hoping someone can shed some light on...I am designing a small 50'x40' structure with masonry walls and a timber framed roof (plywood sheathing/wood trusses). The wind speed and other factors are such that I am allowed by the IBC to use empirical design for the masonry. This structure has a gable roof with a 10' eave but the height at the gable end extends to almost 21' at the ridge. Using empirical design, I have no trouble getting an 8" block size to work along the eave edges (meeting h/t of 20 or 18). However, at the gable end this requirement leads to a 12" or larger block.
First off, I would assume that the h/t requirements apply to the gable end as well as the sides supporting the truss bearing. What is the typical framing used to get an 8 or 10" block to work at the gable end? If a gable-end truss is used to terminate the masonry at 10', is there anywhere I can find details for connecting the truss to the top of the CMU; as well as how to brace the gable truss back to the roof sheathing for out of plane loading? Is there a different detail that typically be used?
First off, I would assume that the h/t requirements apply to the gable end as well as the sides supporting the truss bearing. What is the typical framing used to get an 8 or 10" block to work at the gable end? If a gable-end truss is used to terminate the masonry at 10', is there anywhere I can find details for connecting the truss to the top of the CMU; as well as how to brace the gable truss back to the roof sheathing for out of plane loading? Is there a different detail that typically be used?






RE: Empirical Masonry Design
If you must use a gable end truss, there are two options. You could provide OSB for all or part of the ceiling, thus creating a flat diaphragm that braces the end wall at 10'. Or you could provide diagonal 2 X 6's to brace the top of the CMU up to the roof diaphragm.
DaveAtkins
RE: Empirical Masonry Design
RE: Empirical Masonry Design
RE: Empirical Masonry Design
RE: Empirical Masonry Design
DaveAtkins