Kris Ericsen
12-12-2010, 12:39 PM
Generalized cracking along and across mortor joints in Alaska
This CMU constructed warehouse in Anchorage is 50' by 50' by 24' high built in 1983 using conventional 8" by 8" by 16" block. Rebar spacing is unknown but is assumed to have met 1976 or 1980 UBC. There are no mezzanines, pilasters or any other interior columns and full span Steel Bar type Trusses are assumed to stand about 48 inches in height; subtracting the interior ceiling drywall height from the outside roof to ground height, with no access to the truss space.
The two types of cracking are:
1) Generalized cracking both along and across the mortor joints over the entire long south facing wall; with a curious more pronouced cracking pattern of an approximately 8' by 10' grid seemingly super imposed upon the generalized joint cracking.
2) Moisture intrusion freeze cracking along the unprotected & un caped parapets and wing wall extensions.
The slab and support structure/footings appear to be stable; in that no differential movement/displacement is appereant.
My hunch is that the large wall area, without pilasters or other architectural reinforcement; has been subjected to so much Seismic stress over the decades, that the motor joints have largely failed, leaving the Rebar to hold the wall together.
I guess the main questions are-
Can the wall continue to hold up and do it's job into the future, as it has done in the past?
Will the appearence be a Deal Killer in the present or future that could come back on me?
Should I refrain from offering conclusions and just punt the whole issue over to an Engineer for a formal analysis?
I'd appreciate your thoughts on this inspection that I promised to complete by Tuesday 12/14.
Thanks
Kris Ericsen ICBO ICC
Anchorage AK
This CMU constructed warehouse in Anchorage is 50' by 50' by 24' high built in 1983 using conventional 8" by 8" by 16" block. Rebar spacing is unknown but is assumed to have met 1976 or 1980 UBC. There are no mezzanines, pilasters or any other interior columns and full span Steel Bar type Trusses are assumed to stand about 48 inches in height; subtracting the interior ceiling drywall height from the outside roof to ground height, with no access to the truss space.
The two types of cracking are:
1) Generalized cracking both along and across the mortor joints over the entire long south facing wall; with a curious more pronouced cracking pattern of an approximately 8' by 10' grid seemingly super imposed upon the generalized joint cracking.
2) Moisture intrusion freeze cracking along the unprotected & un caped parapets and wing wall extensions.
The slab and support structure/footings appear to be stable; in that no differential movement/displacement is appereant.
My hunch is that the large wall area, without pilasters or other architectural reinforcement; has been subjected to so much Seismic stress over the decades, that the motor joints have largely failed, leaving the Rebar to hold the wall together.
I guess the main questions are-
Can the wall continue to hold up and do it's job into the future, as it has done in the past?
Will the appearence be a Deal Killer in the present or future that could come back on me?
Should I refrain from offering conclusions and just punt the whole issue over to an Engineer for a formal analysis?
I'd appreciate your thoughts on this inspection that I promised to complete by Tuesday 12/14.
Thanks
Kris Ericsen ICBO ICC
Anchorage AK