Question
About to go to settlement on a home, and my home inspector noticed that the retaining wall on the property which is about 5 ft high in an L shape around the property has no drainage (weep)holes. Not sure what the bulder or contractor was thinking. What is the proper way to have drainage installed, it is a lot of wall about 25 ft in the front and 40 feet in the back what would you guess it would cost to fix this problem?

Answer
Hey, Scott.

I don't know what it would cost to fix the problem because I've never done it, don't know anyone who has done it, and don't consider it a problem worth fixing, especially on a five-foot retaining wall. If it was, say, twenty feet or more, it might be a different story because of the amount of wet soil that would be behind the wall.

As a home inspector myself, I think this is one of those problems that many home inspectors note in order to make themselves appear knowledgeable. Should there have been drainage holes installed? Possibly. However, in desert climates, such as where I live, very very few builders install them because we have a sandy soil and we don't get much rain.

Instead of spending thousands of dollars -- and I'm pretty sure that's a minimum of what it would cost -- simply create a drainage culvert around the top of the retaining wall. You don't even have to make it a concrete culvert. Just anything that will drain water off of the retaining wall soil. What I have done with success is dig a trench around the top, put some landscape plastic down, and then cover the plastic within landscape rocks that have a color to match the retaining wall. Then I put some gardening containers on the top of the retaining wall to soften the stark retaining wall with seasonal flowers and vines.

Hope that helps.

Russel