I have to evaluate the floor capacity of an old building. they want to convert it into a dry storage facility. so knowing the floor capacity is necessary. the building floors are supported on bar joists that have round bar top and bottom chords...also the web member.
Im having a heck of a...
everything is steel. flat bar or small tubes for the ties. they can handle the tension.
your concern is about the the rafter spread or thrust on the end beams/columns...thus your comments about ties. but my question is simply about the vertical support of the ridge, whether the rafters can do...
Mmarlow,
the latest version of the sketch shows rafter and collar ties.
the W shape was the ridge because I first sized it spanning the length of the building. with end columns.
if the rafters provide vertical support...then the ridge can be a rect.tube and much smaller.
Im not going to detail...
mmarlow,
so if there are rafter ties...you say the rafters support the ridge vertically. meaning the ridge beam is sized using the rafter spacings as ridge spans?
btw,mmarlow, collar ties are located in the upper third of the rafters and provide tension in uplift to prevent the rafters from separating from the ridge.
please address the posed question.
for sloped rafters bearing on the top plate of a wall on either side of a ridge beam, on a gabled roof...dont the rafters offer vertical support for the ridge. thus the ridge span is the rafter spacing. or is this for roofs with enough pitch that the rafters have a significant vertical...
