Technical Articles
Hollow Core Openings RFI and Approval Checklist
Prepare a hollow core opening RFI with unit records, coordinated drawings, named reviewers and written project-specific approval before releasing a change.
A late cable route, pipe riser or equipment change can leave a contractor with an opening request that was never included in the hollow core package. The first useful deliverable is a documented decision tied to the actual plank and current drawings. Keep the proposed change on hold until the project-specific structural review and written authorization required by the project's approval process are complete.
This checklist helps owners, contractors, precast coordinators and building-services teams prepare that review. It covers information, responsibilities and records. It provides no drilling method, safe opening size or acceptable position.
The question behind the checklist
In a public construction discussion, a poster describing work on a precast hollow core slab wanted to add a cable penetration and asked how to locate the internal voids. It illustrates the gap between a service requirement and the product information needed to assess it. Read the original question.
A photograph and an estimate of slab thickness leave important questions unanswered. Which producer supplied the unit? Which plank mark is involved? Is the opening already covered by the approved documents? Have later changes affected that review? Put those questions into a single request for information, or RFI, before seeking a decision.
Start with the approved opening schedule
PCI Northeast’s hollowcore guidance says opening sizes and locations should reach the precaster during shop-drawing coordination so they can be considered in the plank design. It identifies coordination across trades as a general-contractor responsibility. The practical implication for a late request is to retrieve the approved opening schedule and establish exactly what has changed. PCI Northeast hollowcore FAQs.
Oldcastle Infrastructure’s pocket guide gives a concrete example of a manufacturer’s approval process: additional openings absent from the returned approved shop drawings require written approval from Oldcastle Engineering. This is that supplier’s published requirement. Obtain the applicable requirements from the actual manufacturer on your project. Oldcastle guide, printed page 40.
Give one person responsibility for the request
For the coordination workflow below, nominate an RFI owner. This person gathers the trade requirement, controls the document revision and routes the question through the project’s agreed review process. The role does not confer structural-design authority.
Identify the people who must respond: the manufacturer’s technical contact, the responsible structural engineer, the affected service designer and the contractor’s coordinator. Record any owner or facility-management approval needed for the proposed service change. In an existing building, also identify who holds the original construction and alteration records.
Separate the questions each party must answer. A service designer confirms the required route. A manufacturer provides product-specific information and its technical response. The responsible engineer determines the structural review required under the project’s appointments. A commercial approval or schedule instruction should not be recorded as structural approval.
Use a four-column RFI register
The following register is a suggested document-control tool. Adapt the named roles and closeout requirements to the contract and project review procedure.
| RFI field | Information to record | Owner of information | Evidence needed to close the item |
|---|---|---|---|
| Unit identity | Building, level, grid and plank mark | Contractor or records custodian | Marked plan reconciled with available product records |
| Document baseline | Drawing numbers, revisions and approval status | Document controller | Complete current reference set |
| Service requirement | Purpose, proposed geometry and requested location | Service designer or trade coordinator | Coordinated request drawing with dimensions and revision |
| Existing conditions | Relevant photographs, known alterations and missing records | Site team or building representative | Dated evidence with location labels and stated limitations |
| Product information | Manufacturer, unit designation and available design records | Manufacturer or records custodian | Information linked to the identified unit |
| Technical decision | Questions for manufacturer and responsible engineer | RFI owner | Written response covering the precise proposal |
| Conditions and dependencies | Required further review, evidence or approvals | Responding technical authority | Named owner and closure record for each condition |
| Change control | Differences between request and approved response | Document controller | Superseded files withdrawn and revised request tracked |
| Closeout | Final authorized documents and required completion evidence | Contractor’s coordinator | Reviewed record set delivered to the agreed custodian |
Make missing information visible
If records are incomplete, say so in the RFI. Distinguish a verified plank mark from a presumed one, an original drawing from an unconfirmed copy, and a documented alteration from an observation. Ask the manufacturer and responsible engineer what additional investigation or evidence they require.
Keep any investigation instructions and findings with the same request. A report that describes existing conditions should remain identifiable as evidence for review. The approval record must state who accepted the proposal and which documents their decision covers. Avoid a register entry that simply says “checked” when the reviewer, scope or conditions are unknown.
Where the manufacturer cannot be identified or contacted, record that limitation and ask the responsible structural engineer to determine the appropriate review route. Do not fill the gap with a typical product section from another supplier.
Close the approval loop before releasing the change
Before the contractor releases the proposed work, reconcile the written response with the latest service drawing. Confirm the unit identification, request revision and any dependencies. If the proposed location, geometry or surrounding arrangement changes, send the revised proposal back through the required review process.
Keep unresolved conditions visible to the people arranging the work. Record who is responsible for closing them and where the evidence is stored. After the authorized work, collect the completion records required by the responding technical authorities and project procedure, then update the as-built information. An email attachment left in one person’s inbox is a poor long-term record of an alteration.
Prepare a reviewable technical question
If you need help organizing the information, use the PRECAST.WORLD technical desk. Include the country, manufacturer if known, drawing status, plank identification, proposed service requirement and the specific unanswered question. Share only documents you are authorized to provide.
The technical desk can help frame the request. Project-specific structural review and written authorization remain with the responsible structural engineer and other designated approving parties, including the manufacturer's technical team as required by the project. If the manufacturer is unavailable, keep the change on hold while the responsible structural engineer establishes the appropriate review route under the project's requirements and the required authorization is obtained.