Inspect Retaining Walls

Retaining walls hold back thousands of pounds of soil — a failing wall can collapse suddenly and cause significant property damage or injury. Inspect once a year after spring thaw and rains, when soil saturation is highest. What to look for: Leaning — step back and look down the length of the wall. Any visible lean or curve that wasn't there before is a red flag. Small amounts of lean can sometimes be stabilized; significant lean usually means rebuild. Bulging — pressure from soil or poor drainage behind the wall pushes individual blocks or stones outward. Cracking — horizontal cracks in concrete or masonry retaining walls are serious; vertical cracks are less urgent. Drainage — the most common cause of retaining wall failure is water pressure building up behind the wall. Check that the weep holes (small openings at the base of the wall) are open and flowing, especially after heavy rain. If no water comes out after a soaking rain, the drainage aggregate or filter fabric behind the wall may be clogged. Concrete walls: check for spalling (surface flaking) caused by freeze-thaw cycles — seal exposed rebar before it rusts and expands, cracking the wall. Timber walls: probe with a screwdriver at the base of each timber — rot at ground level is the #1 failure mode. If you find significant lean, bulge, or drainage failure, consult a structural engineer before the next winter frost cycle, when the problem always gets worse.