I am mid-project in a DIY yard project. I have subbed out a large retaining wall to a civil / wall contractor. It’s 220 feet long, between 2-5′ in height, and makes 2 90-degree turns. It’s built to code with CMU blocks and has an overkill of rebar in it and through the 26″ wide and 14″ deep footer. I’m in Southern California, so it’s a dry climate. I plan to have the face of the wall stuccoed.
The wall just went up this weekend, but hasn’t been filled with concrete, yet. That is coming this weekend. Before he comes back on Saturday morning I wanted to get a few things cleared up for my own knowledge and to know what to ask for to make this wall last. The wall has a lot of room behind it now, but will be backfilled with 12″ of 3/4 gravel and then compacted and graded soil. No landscape fabric.
When reading on the Internet, the topic of sealing the back, “positive” side of the wall has come up quite a few times. People on the Internet say both you should NEVER seal a retaining wall and others say you should ALWAYS seal a retaining wall. The never crowd says that hydrostatic pressure will build behind the waterproofing and lead to a wall failure. The always crowd says that letting water into the blocks will lead to the blocks deteriorating and the stucco peeling off of the front face in a few years. Some places even seem to have local building codes that either require it or require you not to do it. My local building code does not even mention sealing the backside of retaining walls either way. What is reality – should you seal the back like a below-ground foundation or not seal it at all?
Thanks in advance for your help!