this blog is a record of the house that I helped to build along with my class during the Carpentry pretrade course I did at SIT chch

Sunday, 12 August 2012

crack injection

recently I have been working on a commercial tilt slab building doing crack injection to fix damage from the Feb 2011 quakes here in Christchurch.
This process involves locating the cracks, grinding off the paint to expose them, any cracks that are over 0.2mm in width then have 30mm deep holes drilled at 120mm centres  to allow injection, a sealant spread over the the total length of the crack then plastic injection nipples are glued on.
Once the glue has set a epoxy resin is injected into the crack through the nipples.
once the resin has set the nipples are removed and the sealant is ground off and the crack plastered over to allow for repainting.
this is a very time consuming process that can be quite tedious but I quite enjoyed it.

the building with cracks exposed
blown out panel that will need replacing
grinding and measuring crack lengths
crack with injection holes drilled
cracks with sealant and nipples glued on
same again using a different sealant

holes with nipples removed showing resin, sealant has been scrapped off