Allowable Lateral Deflection on Masonry Wall 1

[damo74]

Hi folks. I'm design a steel A-Frame to support a portion of the roof of a dwelling. When I analyse it using a pin and roller support, I get a certain amount of horizontal kickout at the eaves, as expected. The supporting walls are block cavity masonry walls. Usually I would use a limit of height/300 for allowable horizontal deflection at the eaves of walls.

Can anybody give me some more advice on what limit to use?

Should my deflection be based on live load alone, or dead and live together? I would assume that it would be live only as the walls would only be plastered after the roof has been constructed and the frame is supporting the dead load. Is this assumption accurate?

 

[DaveAtkins]

I think height/300 is reasonable, since this is the same as span/600.

The masonry walls will see dead load plus live load, so that is what I would use for checking movement.

DaveAtkins