Ideas from Ed: The Small Wall

“Ideas from Ed” (September 2019) Ed is a do-it-yourselfer who is happy to share some of his ideas and experiences in
this monthly column. This month:  The small wall

This was a rather interesting project undertaken with the help of my son.  I don’t have any real good “before” pictures,
but you might be able to see a few things in the picture below.  The hillside retaining wall was in very poor
condition and ready to collapse.  There was an old brick planter built on the slab which was in bad shape and more “in
the way” than anything else.  The wooden posts holding up the small roof were rotted and decayed.  Our goal was to remove the planter entirely, replace the wooden posts with fluted columns, and, mostly, to replace the
wall.  The wall work is the focus of this month’s article.

I won’t go into details here about removing the planter or replacing the support posts.  You can see what was done in some of the later pictures in this article.  Removing the old wall was not all that hard, since its condition was so bad.  What IS a big deal, however, is planning for drainage behind the new wall.  You can see there is direct runoff from the hillside above plus downspout water nearby to contend with.  Here we began dealing with the drainage concerns by placing a perforated pipe at the base of the wall.  Note that the perforations are only on one side of the pipe, and they go facing DOWN.  As long as the pipe has “grade” (slope in one direction), water will seep in and flow downward.  You should also note that roofs make a LOT of water, so the goal here was to deal with groundwater only with this pipe along the slab, and take the downspout water separately to another outlet on the ground surface away from the wall.  The groundwater was tied into a nearby drainage pipe (not fully shown in the pictures).

Once the type of block to be used was selected, it’s critical to understand how they are to link together for strength.  Some types stack vertically, some have a slight offset against the hillside, some have internal connectors, etc.  (Read the directions that come with the blocks!)  We chose blocks that stack vertically, but have fiberglass “pegs” that are inserted into the tops of a row of blocks, such that the next row sets down onto those pegs.  That aligns things properly and makes for a stronger connection between rows than if the weight of the blocks alone was keeping it all in place.  Then the cavities in the blocks are filled with gravel.  The bottom row is the most important, and NEEDS to be level and plumb, as subsequent rows depend on that row for support and alignment.

Gentle curves can be made.  The hardest part might be (and was) that no “half-blocks” were available.  So to start against the building, we had to use a saw with the appropriate blade to cut some in half.  That permitted the system to be a half-block offset side-to-side, from row to row, thus making nice vertical lines – almost like shingles on a house.

Top-row “finishers” WERE available, and capped the wall nicely.  With a little cleanup and some plants tossed
on for good looks, the wall presents nicely!

I hope all your projects go well.  Thanks for reading, and happy restoring!

Ed