Door Undercut & Finished Floor Clearance for Bulk Orders

1. Define what the bottom dimension means

“Leave a gap under the door” is not enough for a repeated order. The buyer, supplier and installer need to know which two surfaces the dimension describes, and whether the floor finish is already included. Keep the actual leaf height separate from the nominal opening description.

For the wider opening dimensions, use the door leaf, rough opening and jamb-depth guide. This guide focuses on the lower opening detail rather than replacing that full schedule.

2. Coordinate floor levels through the swing path

Ask the site team to confirm both sides of the opening and the area swept by the leaf. A floor may be level at the closed position yet rise where the door opens. A tile-to-carpet transition, threshold or bathroom level change also needs its own detail.

• State whether the survey describes bare substrate or completed flooring.
• Identify the approved floor build-up and reference level on each side.
• Record the threshold profile, position and height relative to that reference.
• Confirm swing direction and any higher surface within the swing path.
• Separate confirmed measurements from proposed or unmeasured conditions.

Use a section drawing or marked-up site survey for the vertical relationship. Photographs help explain the condition but cannot replace dimensions or the approval reference.

3. Treat leaf-only and prehung supply differently

Replacing a leaf in an existing frame: provide the frame’s head reference, actual floor condition, existing leaf size and hinge positions. If new flooring is planned, the old leaf is a reference to review, not an automatic production template. See the hotel replacement compatibility checklist for the other hardware checks.

Ordering a new frame or prehung set: confirm where the frame will sit relative to the completed floor, which dimensions the assembly drawing uses, and who approves the installation reference. Coordinate this before repeating one set across rooms. The term “prehung” alone does not define the future floor level.

Mixed room packages: distinguish bedroom, bathroom, corridor and service openings when floor finishes, thresholds or seals differ. Group quantities by the approved detail rather than by appearance alone.

4. Confirm construction and trimming limits

A supplier’s published allowance for one door cannot be transferred to another model. For a wooden or composite leaf, ask which edges can be adjusted and how the selected construction limits that work. For a PVC-laminated surface, clarify how an approved cut edge is treated. For WPC, confirm the actual profile, lower-edge construction and permitted machining method; the material name does not establish a universal cutting limit.

Request written instructions before allowing site adjustment. Where the required height cannot be achieved within the selected product’s approved method, review a different supplied dimension or coordinated assembly instead of planning an unapproved cut. Review interior door systems and WPC door systems against the room schedule.

5. Resolve ventilation, seals and performance requirements together

If a room needs air transfer, ask the project’s mechanical designer to specify the intended route and opening requirement. Do not choose a larger bottom gap simply from a generic bathroom rule. If a bottom seal or automatic drop seal is specified, include its model, preparation drawing and the floor or threshold it must meet.

For an opening with fire, smoke or acoustic requirements, obtain the evidence and installation instructions applicable to the complete proposed assembly. A permitted cutting operation does not by itself confirm an acceptable installed gap or performance. Check the current project and destination-market requirements with the responsible designer or approving authority; this article gives no universal numerical clearance or VISFURN performance rating.

The WPC frame and threshold guide covers the rest of the wet-area interface.

6. Send a quote-ready floor coordination sheet

Attach the door-bottom and floor-coordination CSV template to the existing RFQ form when this detail affects your project. It is an optional supplement to the door schedule, with no assumed gap, trimming value or product specification.

1. Opening and order: door marks, application, quantities and measurement units.
2. Dimensions and references: actual leaf height, frame or head datum, floor build-up and finished levels on both sides.
3. Bottom detail: required clearance with its reference points, undercut definition, threshold and any seal model.
4. Product limits: selected construction and written trimming or cut-edge treatment requirements.
5. Approval and delivery: drawing revision, confirmation status, destination and required project date.

If some fields are unknown, identify them in the inquiry and send the information already available. Do not fill an uncertain production dimension with an assumed “standard” value.

7. Release a repeatable detail before the bulk order

Have the responsible project team review a representative opening with the intended floor and threshold detail, leaf construction, frame position and hardware. Record which dimensions and instructions are approved. For phased flooring or multiple room types, retain separate references where the conditions differ.

If the floor finish changes after approval, revisit the affected door marks before repeating the original height or cutting instruction. Keep that revision connected to the packing and room schedule so the receiving team can identify the correct variant.

Technical references and scope

The Steel Door Institute glossary explains hollow-metal undercut terminology. JELD-WEN’s trimming guidance illustrates why modification limits depend on the product. Allegion’s clearance versus undercut explanation, published in 2016, provides coordination context, not a current code specification. References checked 14 October 2026; their product allowances and ratings are not VISFURN commitments.