Actually, I do not need to be vindicated by the photo, as my concern in this post is based on standard plumbing practices. But this posting of the two photos makes a great point! I can tell you that, time and time again, an inspector will go under a home and find that the temperature pressure relief valve drain line goes straight down into the crawl space. Now, granted, this is better than no pressure relief valve or drain, but sure not good in the category of fending off wood destroying organisms. Even though most plumbing codes specify the TPR drain should be in a visible location, I have had licensed plumbers tell me that they see this as "no big deal." As a Washington home inspector, we have to call that out as a conducive condition and I finally got a great example of why. The top photo is the TPR drain: Straight down into the crawl. The lower photo is the vapor barrier underneath. The problem is, water was coming out of the TPR valve and that results in the water below. If you think that is of no consequence, let me go on to state that the crawl space was afflicted with an anobiid beetle problem. This pest gives no breaks when it comes to excess moisture. Hence, this extra water was bad news for this crawl space. The funny thing is, generally it is so easy to take a few extra minutes and route the drain line properly outside. Heck, it can even be done with CPVC plastic pipe which is easy to cut and glue. 

Thanks for crawling by.

Steven L. Smith

www.kingofthehouse.com

Bellingham Wa property inspections