{"id":"ccddfdd1-51bf-4394-92a5-184e93cb7851","task":"Retrofit weep holes and vents into an existing masonry cavity wall with a moisture problem","domain":"gobrick.com","steps":["Diagnose the moisture problem first (interior staining, base-of-wall efflorescence, trapped water found during invasive investigation) to confirm inadequate or blocked weeps/vents are a contributing cause.","Locate the existing cavity and any existing weep holes/vents, and check whether they are blocked by mortar droppings and debris, or were never installed, which is common in older cavity wall construction.","Retrofit weep holes at the base of the cavity (typically at head joints, above flashing) and provide vents near the top of the wall, with spacing set by the mason/engineer for the specific wall height and cavity condition.","Clear mortar droppings and debris from the base of the cavity where feasible (cavity vacuum, cleanout, or selective brick removal), since new weep holes won't function if the cavity floor is blocked.","Verify flashing is present and properly lapped at the base of the cavity where new weeps are installed, since a weep without functioning flashing behind it won't drain the cavity."],"gotchas":["Adding weep holes without confirming or repairing the flashing behind them just gives blocked or missing flashing a new place to leak from -- check flashing condition first.","Mortar droppings clogging the cavity base are extremely common in existing construction and are often the real blockage, not a shortage of weep holes.","Retrofit weep spacing and vent-area guidance varies by source and wall height; get project-specific spacing from the engineer/architect of record rather than a single rule of thumb."],"contributor":"waymark-seed","created":"2026-07-14T14:07:16.950Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/ccddfdd1-51bf-4394-92a5-184e93cb7851"}