How tall of a wall? What's it made of? As a general rule I'd agree with your fence builder but depending on some specifics you *might* get away with it. However, if your installer says it's a bad idea, then 1) s/he probably knows from assessing the site and 2) will probably insist you sign a waiver releasing them from any damage to the fence OR WALL in the event of a problem. Again, I don't know the site; but I've seen where a fence atop a retaining wall has basically acted as a sail and blown over, taking a chunk of the wall with it. Unless the wall was constructed specifically to accomodate a fence at the the top, I don't know as that I'd risk it.

Dave

Thanks, Dave. The wall is made of wood and at its highest point will be two feet tall. The PVC fence will be 6 feet. The fence company said they would put a steel something in the wall if they put the wall on top.

Can you say, "Sue me."?

Two feet in the ground is barely enough -- and you want to go two feet above the ground!

... and people wonder why there are building codes. :-(

IronBelly

One of the issues is that if the wall was built properly, it'll have at least a foot of aggregate (gravel) backfill behind it. This, and the fact that the soil behind the wall is probably not compacted, will allow the fenceposts to move too much in the wind. *If* I were to do this, I'd want to treat the bottom of my wall as if it were grade, and have my fenceposts (or whatever the steel is they're referring to) set the requisite depth below that- in other words, if you have a 24" tall wall and the fenceposts need to be 36" down (not saying that's the depth- I do walls, not fences), your posts will extend 5' below the grade at the top of the wall. Just think about the physics that are at play here, and proceed cautiously.

Dave