Heavy Stone Retaining Wall

When you are burying a house, one of the tricky bits is to keep the dirt from spilling where you don’t want it…  Like into the doorways.  I have a number of retaining walls planned for this build, and, just to keep things interesting, I have designed each one a different way.  This section is about the “Heavy Stone” wall by the back door/patio.  More details below, but first…  the Video

The Video

Cost

I had assumed that those concrete blocks were the cheap way to build a retaining wall and the fancy quarried sandstone was the expensive way.  Of course, I probably still would have used some real stone…  However, when I looked into it, At least for the cost of the stone, the real stone was cheaper.  Of course, that doesn’t factor in things like the cost of the mortar, which was about 5$ per level on my wall, so still not too bad.  The real cost of building a wall like this is time…  Those precast concrete block walls probably wouldn’t have taken me nearly so much time, but no regrets on choosing to do this one the hard way.

Engineering

Retaining walls often fail.  Keys to keeping this one from going down included…

  1. Wide heavy stones (heavy stone is actually what they called this size at the quarry) that are substantial and want to stay where you put them.
  2. Leaning the wall back against the earth load.  Before the earth can tip your wall over, it would first need to straighten it out.  Gravity helps you keep things as they are.
  3. Curving the wall against the earth makes it a lot harder for the earth to tip it over, just as it is harder for a mug to tip over than for a domino.  Making the wall concave helps even further because the loads against it are in compression, something that the stone handles with ease.
  4. Behind the wall, I had plenty of drainage.  Drain gravel, landscaping fabric and HDPE corrugated/perforated drain tube were working to make sure that water pressure never gets a chance to build up behind the wall.
  5. Layers of carpet were also used in the dirt behind the wall.  This “geo-textile” idea is used by highway engineers to keep dirt from shifting under ramps.  I would have liked to have used more layers, but some is better than none.

 

I watched lots of videos online about how to build a retaining wall that lasts.  I recommend anyone who is planning to build there own do the same, and don’t be tempted to take shortcuts.

The Gallery

Here is a gallery of pics with detailed captions.

Making Copper Tiles for the Ridge Cap

I have always been a big fan of Copper roofs, especially when they patina.  Copper roofs last hundreds of years and just look so much more interesting than asphalt ones.  Problem is that they are just too expensive.  But with my earth sheltered home project, I was going to have very few square ft of roof, so copper suddenly became affordable again.  Making the tiles myself would also significantly reduce the cost. For this first part, I was really just wanting to put a copper cap on the front and back ridge of the garage. This post is about how I did that.  At some other point, I may also make diamond tiles to cover a few hundred feet of regular roof…  But first, this video

The Video

Alternatives

I had put stucco on the front and back of the garage and this ridge cap was to cover the 12-inch ridge along the top of the shotcrete wall…  Looking back, I could have done it a few other ways.  For instance, I could have just wrapped the top of the wall in lath and then just put stucco right up over the ridge.  Another option would have been to put tile up along the ridge.

I had planned to use copper shingles for all the skylight caps also, but now that I am older and wiser, I plan to just cap the second skylight on the garage with copper and switch to using large format tiles (that I can get for about 1$/sqft) on the other 5 skylight curbs.

The tools

The Press Break Roll was pretty fun to use and getting it 40% off from Harbor Freight made it even better.  One of these days I’ll put more details about it under the “tools” section of this website and maybe make a more focused video.  In the meantime, I can put the original crate back on top of it to keep the dust off so it is ready to use next time I am in the mood.

Along with that, I needed a nice mallet for pounding the copper, good aviation snips for cutting it, pliers, etc.  Generally speaking, pretty standard stuff.

The Gallery

Pictures help tell the story, so I put a bunch in the description of each image…  Enjoy.