Many people have recently asked me about landscape walls. As a result of those inquiries, I’ve drawn up a cross section of a landscape wall and rubble trench foundation for you to check out below. This is a basic design that can be used in most locations. Some building departments allow for rubble trench foundations within the codes while others are less accustomed to them. Be sure to discuss the potential to use this design before you commit to the design. You may need to make changes to the system or simply educate the building officials around the effectiveness of the rubble trench design.
I’m open to feedback on the design. If you think there’s a better system, let me know. I always like to hear how other people do things. As a builder, I always spent time visiting other contractor’s job sites and talking to them about how they did things. I’ve learned a LOT by talking to others and I continue to learn this way today. One detail I often put into landscape walls in wet climates is a metal wall cap. The caps are custom made by the local metal shops (those who fabricate metal roofing are best) to fit over the top of the finished wall. You need to provide some anchoring points for the caps within the wall, but that’s not shown here.
Simply let in a 2x at the top of the wall so that the bottom edges of the roof cap can hit it during installation. be sure to install the wood nailers before the mesh so that the mesh can lock them tightly in place. Get the wall cap in a color that matches or compliments your plaster and you’ll barely notice it’s there (or you’ll see it as an asset to the design).
One point around landscape walls and moisture. It’s really not that big of a deal if the bales get wet and ultimately rot out. That matters BIG TIME in a house, but a wall is just that, a landscape wall. The bales are not acting as insulation, they’re basically acting as forms for the plaster. Once the mesh is properly installed and you add 1 1/2″ of plaster to each side of the wall (all the way up and over actually), the bales can rot out without the wall collapsing.
Of course, the overall strength of the wall is better with the bales in place, so protect them as best you can. Just don’t loose sleep over water getting in through a failed washer on a screw that attaches your wall cap. The wall will be fine!