Part H · the register

The Retaining Wall at the Top of Your Kirkwood Lot Carries the Roof Crew

A retaining wall on a sloped Kirkwood lot can take the ladder, the pallets and the bin weight, so check its cap and footing before the crew stages.

Many Kirkwood lots fall away from the house at the back or along one side, and the drop is often held by a stone, block or poured retaining wall. On a roof job that wall is more than a boundary. It becomes the place where the crew sets the ladder foot, rests a pallet of shingles, steadies a hand while climbing, or lets the dumpster load sit close to the edge. Each of those is a load the wall was never built to carry as a working surface, and a roof contract rarely mentions it.

Town roofing

Older Kirkwood blocks often have narrow side yards between the house and the lot line, and that side yard is frequently the only route a crew has to the back slope. When the route runs along a wall, the wall decides where the ladder can land. A wall two feet high changes little. A wall four or five feet high, with a grade drop behind it, means the ladder foot either sits on the lower yard with a long reach to the eave or lands on the cap, where it can slide on wet stone. A crew that cannot reach the eave from the side yard will often ask for a second staging point, and that request is where a wall gets loaded without anyone deciding it should be.

Freeze and thaw works on these walls every winter. Water soaks the soil behind the wall in February, freezes in the next cold snap, and widens the gap in the joints. Each cycle pushes the wall a little further. Weep holes clog with silt, and a cap stone that looked fixed in October can rock when someone steps on it in April. A roof crew working in spring is standing on a wall that has been loaded all winter by the ground behind it.

The wall also shows where the roof water goes. If the downspouts empty onto the lower side yard, the water runs downhill and collects at the base of the wall. Trapped water behind a wall pushes outward, and that pressure is slow and steady rather than sudden. You will not see it from the driveway. You may see a bulge in the face, a stepped crack that follows the mortar, or a white film of salts at the joints after a wet week.

Kirkwood's permit desk handles the building side of work on the house and lot. A cap reset or a few repointed joints is usually small work, but a section that has to be rebuilt, or a wall that holds back a driveway or a structure, may need its own review. Ask the city's permit desk whether a wall repair is a separate filing before the roof date is set. Finding that out after a stone has come off during staging is a much harder conversation.

The roof crew's needs and the wall's limits meet in a few places. The ladder foot, the material stack, the dumpster and the tarp stack at the eave can all sit near the top of the wall. Ask the Keys office at (314) 220-2333 where the crew plans to stage each item, and ask for those positions to be marked on the site sketch.

What it costs

A wall problem found on a roof job belongs on its own line. Resetting a loose cap, clearing a blocked weep hole or repointing a short run of joints is small masonry work, and it is priced separately from shingles, underlayment and flashing. A failed section that needs to come down and be rebuilt is a different number entirely, and it can change the schedule, the dumpster position and the ladder plan at the same time. Those changes should appear in writing before anyone signs, not as an add-on after the first section is open.

Keys puts a written scope, with photos and measurements, in the homeowner's hands. That scope should state whether the retaining wall is inside the roof work or outside it. If the wall is outside, the proposal should say who is responsible for it, when that person will be on the lot, and what happens if the crew's staging moves a cap before that person arrives. A roof price that ignores the wall is not a lower price. It is a price with a line missing.

Waiting costs something too. A wall that is already moving in autumn will move further by the next thaw, and the roof date that follows may be pushed by the repair. Doing the small wall repair first is usually simpler than doing it after a section has been pressed out of line by the ground behind it, because the crew then has to work around a repair and a roof at the same time. Keep the photos taken before the crew arrives, because they are the only record of the wall's condition on the day the roof work started.

What to ask

Put these questions to every roofer who bids on a property with a retaining wall, and ask for the answers in writing.

• Is the retaining wall inside the roof scope or outside it, and is its location marked on the site sketch?
• Where will the ladder foot land, and will any part of the ladder rest on the wall cap?
• How far from the top of the wall will the shingle pallets and the dumpster sit?
• Will anyone check the mortar joints and weep holes before the crew arrives, and will those photos be in the file?
• Who is responsible if a cap rocks or a section moves during staging, and how is a second trip priced?
• Where will the downspouts discharge, and will the route keep roof water away from the base of the wall?
• Does a wall repair need a separate city filing, and who makes that call?

A roofer who answers the wall questions with a single word has not said where the ladder goes. A roofer who answers with positions, measurements and a named responsibility has given you something you can check on the morning the crew arrives. Keep the written answer with the roof contract, and compare it with the photos taken before the first stone is moved.