Minimum number fo hold downs per shear wall? 1

[EngineerofSteel]

I have a two story building with a balloon frame, 22' high. The wall is attached solidly to the main building and has a height:width ratio of about 1:1.15

The tile roof anchors the wall against uplift and calculations do not require a hold down.

However, is there a minimum requirement for hold downs?

I came on to this job after the architect (who calc'd everything himself" was told he needed engineering (he does- the house is very irregular and in seismic zone 4)

This home construction permit was issued under UBC97.

 

[josta]

'97 UBC allowed 90% of the righting moment to be used against the uplift. If there is zero or negative uplift, then no holddowns will be required.

 

[EngineerofSteel]

Then the design is fine as it is.

Thanks.

 

[FSS]

I guess I need more info to believe you don't need holdowns in such a seismic zone.

 

[K2skis]

No uplift no hold down required. However with a big heavy tile roof swaying side to side during a seismic activity it seems very likely that hold downs would be required by calculation. Verify your loads then proceed however you feel most comfortable.