Cracks in Mortar Joints

[scottiesei]

I am working with a contractor on a project which an unreinforced masonry structure was stabilized (sink hole). As always, the walls cracked. My plan is to provide reinforcing details for the significantly cracked areas but I am being asked to provide repairs for the minor "hair line" cracks throughout the entire structure. Typically, I'll leave cracks less than 1/8" to be repaired by the contractor by surface patching, tuck pointing or epoxy. This is the first time anyone has asked about the hair line cracks and its overall effect on the structural performance of the wall. I've done a pretty extensive search of PCA and NCMA docs to really no avail. If anyone has any documents or references regarding the effect of minor cracks on mortar joints I would appreciate a link.
Thanks!

 

[ishvaaag]

Work for a specialty contractor. Ask them certificates to satisfy the official inquiriy about strength. May add even inox rods joining separate layers of masonry.

http://www.ladbs.org/faq/info bulletins/building code/2008/IB-P-BC 2008-056 Crack Repair of URM.pdf

http://www.limes.us/pdf/restore-masonry-injection.pdf

http://www.icc-es.org/Criteria/pdf_files/ac205.pdf

http://www.ndt.net/article/ndtce2009/papers/134.pdf

http://www.hilti.ie/data/editorials/-11639/HIT_HY70_leaflet.pdf

http://www.whitecap.com/static/pages/dot/pdf/ohio/Powers Power-Fast Epoxy Injection Gel.pdf

http://www.simpsonanchors.com/pdf/catalogs/C-SAS-2009/C-SAS-2009-p101-p102.pdf

http://www.simpsonanchors.com/pdf/catalogs/C-SAS-2009/C-SAS-2009-p109.pdf

http://www.uspconnectors.com/pdfs/Submittal7412.pdf

http://www.restorationuk.com/shop/pdfs/focus400.pdf

http://www.permagaurd.com/myfiles/file/Aida Injection Cream Brochure.pdf

http://www.remmers.de/html/uk/downloads/mauerwerksinjektion.pdf

http://bwk.kuleuven.be/materials/Pu...idation and strengthening of masonry 2003.pdf

http://www.quakewrap.com/frp papers/CFRP-Retrofit-Of-Masonry-Walls.pdf

 

[scottiesei]

Thanks for the links. It would be helpful to note that the project is in Florida. I am specifically looking for some type of criteria of when the cracks are acceptable or not.