The wall looked worse than the title photo when we met with the client. It was intact, but crumbling and leaning (collapsing really) from water damage. We did our best to ease his concerns. It wasn’t until we started the demolition that we realized the extent of the damage and solution of the problem. Sometimes, you just have to tear it all down and start over. That was our case this time.
When the excavator dug behind the wall, we found the reason for the failure. A french drain (catching the gutters and most of the side yard runoff) had been improperly installed. Water was seeping down to the old wall foundation and saturating the inner block face. There was no waterproof barrier installed either. We had to remove everything.
Our contract (and building permit) was to reconstruct the old wall. We added 1/2 inch steel rebar vertically and 1/8 inch steel “ladder” horizontally for each block layer. We placed the blocks three tiers high each day and filled the cores (with a mix of half grout and concrete) and let each tier dry overnight.
Your eyes do not deceive you, we mixed all the mortar and concrete in the wheelbarrow.
We made sure to fill all the voids and cracks on the back side of the wall as we progressed. When we reached the original height, we coated the back with roofing adhesive and secured a vapor barrier that also doubled as a vertical french drain. We constructed a new french drain at the base of the new wall connecting to the new PVC pipe with a T-fitting.
We back filled with two foot layers of dirt (which were tamped lightly). We continued to back fill using that method until we reached the top of the blocks. All the extra dirt was mounded to slope away from the wall and a heavy layer of clean sand was added to fill any air voids that remained. Grass seed was spread onto the sand (and took root quickly).
A temporary barrier of colorful flagging was erected until we could build a metal fence to prevent anyone or anything from accidental falling. This was a larger project than most folks tackle but retaining walls are common with uneven terrain. Rock, landscape timbers, brick and even dirt berms usually improve the function and aesthetics of a yard. There is as much to repair around the house as there is inside the home.
Until next time, stay safe and work smart.