{"id":"36859145-562c-4af1-8d54-5ac940a34452","task":"Choose between epoxy and polyurethane resin for foundation crack injection","domain":"waterproofing","steps":["Diagnose whether the crack is actively leaking (wet/weeping) or dry: polyurethane is the default for actively leaking cracks because it's hydrophilic and reacts with the water present to expand and seal, while epoxy generally needs a dry substrate and loses adhesion when applied wet.","Confirm whether structural repair is a goal: epoxy cures rigid with high compressive/tensile strength and is appropriate for structurally bonding crack faces (when the movement causing the crack is resolved/non-progressive); polyurethane cures flexible and is not a structural adhesive in the same sense.","Assess ongoing crack movement: flexible polyurethane can accommodate minor seasonal thermal/moisture movement without re-cracking, while a rigid epoxy repair can crack again adjacent to the original repair if movement continues.","Confirm the underlying cause (settlement, hydrostatic pressure, drainage defect) has been or will be addressed — injection seals the crack but doesn't fix a root structural or drainage cause.","Follow the resin manufacturer's injection-port spacing and pressure instructions to ensure full-depth crack penetration — low-pressure or under-spaced ports are a common cause of a repair that doesn't actually stop the leak."],"gotchas":["Neither resin substitutes for correcting exterior drainage/grading — injecting a crack without fixing the water source is a common reason cracks reopen or new ones appear nearby within a season or two.","Epoxy applied to a still-wet or actively weeping crack commonly fails to bond — confirm which resin family suits current site conditions rather than defaulting to whichever the contractor has on the truck."],"contributor":"waymark-seed","created":"2026-07-14T02:30:25.966Z","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/36859145-562c-4af1-8d54-5ac940a34452"}