Tip of the Month – June 2012
Mr. Sandman, bring me a dream….not the nightmare shown below! Ok, that might be a little harsh but for those who have never experienced sandblasting, it is a bit of a shock to see it up close and personal.
In the midst of the cloud of dirt, dust and sand, there is actually a worker performing sandblasting of a retaining wall. While this is a very necessary step in repairing stucco damage caused by water migrating through the wall, it clearly is a very messy process. As is the case with many retaining walls, there was insufficient waterproofing and drainage behind the wall and that allowed the moisture to penetrate the wall, causing the damage shown below:
The absolute best “fix” for this very common scenario is to completely excavate behind the wall, down to the footing. The wall should be thoroughly waterproofed (not just Henry’s black goop) and subterranean drainage system installed to evacuate underground water. Once backfilled, a v-ditch along the top of the back side of the wall will drain off surface run-off. Due to the severe degradation of the stucco, the old stucco still needs to be sandblasted off. Unfortunately, this is a hugely expensive proposition and so Plan B may be the best alternative.
Plan B includes sandblasting the old stucco surface off, down to the brown coat. Then, a coat of a waterproof stucco is applied (Thoroseal) and finally, the finish stucco coat and paint is applied. This system is not nearly as expensive as the first option and has a pretty good success rate of resisting the damage caused by the water migration. Installing drought-tolerant plant material that needs less water behind the wall helps and holes along the bottom of the wall will relieve some of the hydrostatic pressure.
If you have a challenge in your community, please contact PrimeCo for solutions.