Wednesday, August 24, 2011

Tips On Building A Drystack Stone Wall

 I spent many years as a self taught stone mason
 doing random rubble dry stack walls which I enjoyed doing 
more than just about any other trade that I have dabbled in,
until my body just couldn't do it any more.

The last time I worked at it was this project
at Breitenbush Hot Springs in Oregon in the summer of 2008.

 Let me caution that stone masonry is hard work 
that requires sturdy boots, gloves and attention to what you are doing. 

It is easy to have serious accidents: 
smashed fingers or hands, broken bones, or worse, 
and what follows is not intended as a complete instruction
 but merely as notes to the process.

A safe work site is essential as well as safe practices.

(Please note that this is a reworking of the post:

The site was next to a beautiful hot soaking pool where the path along the pool
 needed to be enlarged to allow conduits for new water and electric service.

 The area below the pools where the wall was to be located was essentially a bog
 that handled the runoff from the pools, 
and a dry stack wall was perfect because it would allow free flow
 of the water through this area.

     The first part was to dig a footer for the wall which is not easy in a bog,
 and a place from which to work and to move stone over.

 The big drawback was limited space to lay out the stones.

      The foundation was essentially a trench filled with rubble 
that was not suitable for use in the face of the wall.

      In selecting stones for the base of the wall,
 you want to use the largest stones at the bottom of the wall 
as they are easier to place and move into position 
and there is minimal lifting of your largest stones.

The back fill here is rubble, 
again stones that are not suitable for the face of the wall,
but which stones are good for the face of the wall?  

Hard to explain in print, but basically you want a smooth face in front
 with an acute angle on the top that slopes downward as it goes into the wall. 

This is all about gravity
 and the next stone on top must have a tendency to slide into the wall not out. 

The earth is constantly vibrating, even though we don't feel it,
 and as the wall ages we want the stones to vibrate inward,
 if at all, making the wall stronger and stronger.

The above photo shows how large the base stones are 
and the next important principle is that at regular intervals you want a stone 
that reaches back into the wall tying everything together. 

The stone with the tape on it would have looked beautiful
 if it had been set with the long side facing out, 
but structurally it would have been weak and wanting to tip out of the wall. 

As it is set above it ties the wall together and makes it much stronger.

      You can also see here how the tops of the stones slope downward
 as they go into the wall. 

Lastly, you can see how the fill stones are rounded and not suitable for face stones. 

As the wall gets higher you will notice the fill stones get smaller.

The wall takes shape and the conduit ( the whole reason for this wall ) is in place.

 The vertical white pvc pipes sticking up out of the rubble are for the railing.

 This photo shows another principle, always tip your wall into itself 
or the bank that you are holding back.

 A rule of thumb is to tilt it in at minimum one inch for each foot of rise;
this wall is much more than that.

      The blue hand truck in the background came from Harbor Freight 
and turned out to be quite good as it had large pneumatic tires and held up to lots of abuse.

 The buckets hold chisels, 3 # mallets, gloves, tape measure, etc. 
and a 2' and 4' level are essential.

The completed wall,
note the larger stones at the bottom of the wall.

You can see here how much the wall leans into the bank which I call the batter.

On the top we added a cap which should give a nice even appearance.

We added these steps to the left end of the wall.

For more on stonework check out Stonework
under LABELS on the right sidebar;
and also check out the post: Stone Walls In Winchester, Virginia
to see more examples of drystack walls.