Originally Posted by TomG
SRW’s are non monolithic, unlike say a poured concrete wall, so there are spaces between the blocks where water can exit from behind the wall. One thing that really cracks me up when I see it being installed is using 4” black perforated flex pipe as the drain pipe behind the wall. IT’S PERFERATED ALL THE WAY AROUND, if any water gets into the pipe it’s just going to go out the bottom of the pipe through the holes. Especially if it is completely surrounded with stone.
Hydrostatic pressure relief is why we put PERFORATED drainpipes behind srw and concrete walls. Without it you may get away with it but in a wall that is close to 10' in height it will be subject to "blow out". Its the nature of water and cold. The stone can and will act as a drainage point for only so long and the blocks can only release so much water, actually very little, so there is no back up if the area above the wall ever floods. The water will exit the pipe in such a case, yup likely no one will ever see water exit that pipe. Maybe in your case you have all the slopes figured out and what not but for $50 dollars it just isn't worth not putting it in. I know I would feel good about it if it were my wall. I've been doing walls myself and with my men for 25yrs and I will be the first to say that alot of our walls were not built with drain pipes, this was a time when there were no engineered jobs or specs, we just did what we thought was best. But with all the training going on today, and icpi (for what its worth) techo blok seminars etc, there really is no excuse but to follow proper install methods. So am I bashing you, not really, I'm just pissed to see someone who does all this work, most of it good, some of it needs improvement but hey what do I know, and to ignore and spread the word that using drains is a waste of time and not required, its just wrong. Whats next, geo textile a waste of time too.