Resources
Specification Compliance and Client Approval
Answering the real question first
If you work on public contracts, your first question is: “will the client accept this?”
The honest answer: stay-in-place formwork is a recognised and widely used method. Its use in culverts, however, depends on the project specification and the client's engineer. This page sets out the process and the documents required.
What MenfeX does not change
None of the following requirements are altered — all follow the project's structural design and specification:
- Concrete class (min. C25/30 for cast-in-place)
- Reinforcement layout and bar sizes
- Concrete cover (50 mm)
- Pour block and expansion joint rules (6 m / 12 m / 24 m)
- Curing period
- Cement selection in aggressive ground
- Culvert geometry per the standard drawings
MenfeX changes the forming method only. The plastic is excluded from the structural section.
Approval steps
- 1
Raise it early
Bring it to the supervising engineer during the construction programme, not after award.
- 2
Submit a technical file
Product data sheet and material certificate, installation detail drawings, a statement that the formwork is excluded from the structural section, the installation guide, and the manufacturer's quality certificates.
- 3
Trial installation
A witnessed trial pour on site where required.
- 4
Written approval
Obtain approval in writing before production begins.
Certificates and documents
| Document | Status |
|---|---|
| MenfeX product data sheet | In preparation |
| MenfeX material test report | In preparation |
| MenfeX lateral pressure report | In preparation |
| Installation detail drawings | In preparation |
FAQ
Does leaving the formwork in place cause a structural problem?
No. The plastic is excluded from the structural section and carries no load.
The structural approach is the same as for the stay-in-place formwork systems already in wide use: the formwork is not a load-bearing element. Capacity is provided entirely by the reinforced concrete section, exactly as in a culvert cast with steel formwork. The design ignores the plastic.
Reinforcement layout and 50 mm cover follow the project's structural design — MenfeX changes neither.
Will the client's engineer approve stay-in-place formwork?
Stay-in-place formwork is a recognised method, but its use in culverts depends on the project specification and the client's engineer.
Be sceptical of any supplier who tells you it is unconditionally permitted. On public contracts, a change of forming method goes through the supervising engineer and is confirmed in writing.
Raise it during the construction programme, not after award. The technical file to submit and the steps to follow are set out on the Specification & Approval page. We support witnessed trial installations on site where required.
Request a trial installation
If you would like to trial the system on your contract, write to us about a witnessed sample installation.