redwood1922
Junior Member
- Joined
- Aug 6, 2011
- Messages
- 33
- Reaction score
- 4
What is reasonable to expect of a concrete contractor who helps repair or retrofit an existing house by adding partial new concrete footings with anchor bolts? I expect that carpenter will use no shims at all to support the house, because Simpson and USP connectors seem to require continuous wood surfaces for seismic rating. If a moderately skilled craft person produces a footing, how close is the top of the concrete footing to design height - or equivalently, how close will the result be to the design clearance for top-of-concrete to bottom-of-girder? Like, within 1/4 inch of whatever specification is on the drawing? Or more like 1/2 inch or 1/8 inch? Will the tops of footings be close enough to adjust for any difference by using a planer to set final thickness of new supporting members? Is the planer idea practical?
I've been looking at readymade plan sets for voluntary seismic upgrades. For example, 2x blocking can lay flat over a new section of mud sill to support an existing girder. Actually the blocking is "thickness as required" according to a FEMA plan set.
The house will be sitting on this blocking. So I think Simpson/USB connectors had better have a nice solid grab on the blocking to connect to girder above and sill or other member below. If the blocking can't be shaved down too much then the wall can't be excessively higher than design. Also, the Simpson and USB catalogs seem to rule out shims for connectors to remain load-rated. So the wall can't be excessively lower than design. I've seen plenty of concrete work that would not be accurate enough for this job I'm describing. That's why I want to know.
I've been looking at readymade plan sets for voluntary seismic upgrades. For example, 2x blocking can lay flat over a new section of mud sill to support an existing girder. Actually the blocking is "thickness as required" according to a FEMA plan set.
The house will be sitting on this blocking. So I think Simpson/USB connectors had better have a nice solid grab on the blocking to connect to girder above and sill or other member below. If the blocking can't be shaved down too much then the wall can't be excessively higher than design. Also, the Simpson and USB catalogs seem to rule out shims for connectors to remain load-rated. So the wall can't be excessively lower than design. I've seen plenty of concrete work that would not be accurate enough for this job I'm describing. That's why I want to know.
Last edited: