Accepting the concrete before you waterproof it: cure, finish, moisture and defects
At the brewery expansion, the foreman finds open tie holes and a rough patch beside the footing joint. The concrete handover sheet says the wall is complete. The waterproofing crew has arrived, but completed concrete work and an accepted membrane substrate are different decisions.
Accept the concrete against the approved waterproofing system’s actual substrate requirements before covering it. Record defects and unresolved conditions by location, then obtain the required correction and acceptance decisions. Do not use one blanket rule that concrete must always be dry: the sheet-membrane source below requires a dry surface, while the crystalline coating source requires a pre-saturated surface. Neither condition transfers automatically to another system.
Make the substrate handover specific
- Identify the accepted system information. Bring the current specification, approved submittal, details and installation instructions to the area. Mark the actual requirements for preparation, concrete age, moisture condition and acceptance evidence instead of carrying limits from the previous job.
- Walk identifiable sections. Use the drawing to divide the wall or deck into areas the crews can locate. Photograph visible tie holes, projections, contamination, voids and other questionable conditions with enough context to find them again.
- Keep repair authority clear. Refer honeycomb, cracks or questionable concrete to the responsible concrete and technical leads. Describe what you observed without deciding that a cosmetic patch is an acceptable structural or waterproofing repair.
- Confirm how conditions will be checked. Agree the project-required method, locations and responsible person for moisture or other readiness checks. A photograph or the wall’s colour does not replace a specified measurement or an acceptance decision.
- Assign outstanding work. List the correction owner, applicable instruction or decision reference, and when the area can be offered again. Where requirements conflict, obtain clarification before turning either version into a crew direction.
- Record the accepted boundary. Identify the exact area, checks completed, decision maker and remaining exclusions. Keep an adjacent unresolved section visible on the handover record so acceptance of one area does not silently release the whole wall.
Common mistakes
- Using a dry-substrate rule for a system that requires another condition.
- Covering a questionable concrete defect with membrane instead of obtaining its repair decision.
- Signing an entire wall when only one section was checked.
Checklist
A usable concrete handover
- Current system and preparation references.
- Located defects and photographs.
- Required condition checks and results.
- Repair decisions and responsible people.
- Accepted sections and unresolved exclusions.
Check your understanding
The concrete sheet says complete, but the approved membrane’s moisture check has not been carried out. Is the membrane area accepted?
