Freeze the configuration
Record equipment make/model, storage position, lowered/raised attachments and whether removable accessories stay on the machine. Separate idle-yard storage from transport or operational enclosure requirements.
DERFLEX / TECHNICAL PROCUREMENT GUIDE / 2026
How to Measure Irregular Equipment for a Custom Tarp
A machine is rarely a perfect rectangle. Exhaust stacks, control cabinets, handrails and sloping housings change the fabric path—and the pattern your manufacturer must build. Use this field-to-factory method to capture a usable equipment-cover specification before ordering custom PVC tarps.
01 Fixed datum02 Three-dimensional profile03 Factory-ready drawing
Real DERFLEX factory imageCoated-fabric supply for custom industrial tarp fabrication
Measure the profile.
Specify the fit.Dimensions • Access • Reinforcement • Fastening
Specify the fit.Dimensions • Access • Reinforcement • Fastening
How do you measure irregular equipment for a custom tarp?
Measure the equipment in its actual parked or covered configuration. First establish a fixed origin and record the maximum length, width and height. Then measure each stepped or curved section along the route the fabric must follow, locate protrusions and openings from that origin, and record the fastening line. Submit dimensioned top, side and detail views—not just a single L × W × H figure—for pattern review and finished-size approval.
The critical distinction
Three different sizes. One approved pattern.
A machine's bounding box is the beginning of the specification, not the end. A custom PVC equipment cover also has to follow real surface geometry and still allow safe installation and removal. For simpler flat covers, see our general custom tarp measuring guide.
MEASUREMENT 01
Equipment envelope
The farthest overall length, width and height in the position that will actually be covered. Includes protrusions, guards and attachments.
MEASUREMENT 02
Fabric travel path
Routes across roof shapes, steps, curves and down to the lower edge. Measure where the fabric will run, not merely the floor projection.
MEASUREMENT 03
Required finished cover
The approved panel and assembly dimensions after fabrication, with openings, drops and fastening design defined. Do not substitute raw cut size.
Figure 01 / Measurement framework
Start from a datum—not a photograph.
Use one physical origin across every view. In the illustration below, X runs front to rear, Y runs left to right, and Z measures height above the same base reference. The shapes and labels are schematic and are not a production drawing.
Side elevation · irregular equipmentSCHEMATIC / NOT TO SCALE
Field capture rules
A consistent reference avoids conflicting measurements.
- Datum O: select a rigid, accessible machine corner or base feature that can be found again.
- X / Y / Z: label directions on every sketch; state which side is front and which is left.
- Stations S1–S3: add more cross-sections wherever the profile changes materially.
- Projection P1: record its origin location, width, height, projection and required cover treatment.
- Path C: follow the proposed cover route with a flexible tape; keep horizontal projection separate.
Safety first. Isolate equipment and measure only in a safe condition using the site’s lockout and access procedures. A standard stationary-storage tarp must not be assumed safe over hot, ventilated or operating machinery.
Seven steps / Field to fabrication
The measurement process for a non-rectangular machine
These steps produce a dimension set a cover fabricator can review, rather than a rough sheet-size estimate. Keep one set of units throughout and record who measured the asset.
Set the origin and axes
Mark a repeatable origin and front/left convention. Sketch the top, both sides and any unusually shaped faces. Put every hardware position and opening on these same references.
Capture L, W and H at outermost points
Measure beyond the nominal chassis or housing: mirrors, rails, projecting motors, guards, levers and stacks may determine maximum size. Record top height and each required lower-edge drop separately.
Map slopes, curves and steps
Take extra stations before/after height changes. Use a flexible tape along the intended fabric route over curved housings; a straight-line floor projection does not equal cover path length.
Locate features in 3D
For each projection, record face, X/Y/Z position, maximum dimensions and whether it must be covered, boxed out, isolated or avoided. Mark access doors, cables, drains, ventilation and service clearance.
Measure the hold-down route
Define which frame locations are safe attachment points and where the finished lower edge stops. Mark straps, webbing, D-rings, eyelets, zipper lines and wear areas from the datum—not by guessed spacing.
Verify and issue a controlled drawing
Cross-check the maximum envelope, critical offsets, both diagonals where relevant, and cover removal route. Attach labelled photos and issue a revision for supplier feedback, pattern approval and repeat OEM orders.
A usable approval package
1. Dimensioned top and elevations. 2. Profile station list. 3. Protrusion and opening schedule. 4. Attachment map. 5. Finished-size request, quantity, use condition and photo set.
Avoid automatic allowances: Do not add a generic 50 mm, 2 in or other assumed hem or seam allowance to every dimension. Specify functional clearance and the required finished cover; ask the fabricator to calculate cutting, seams and reinforcement after reviewing the selected fabric and pattern.
Figure 02 / Dimension schedule
Map protrusions like an engineer, not a guess.
A feature may protrude only slightly yet dictate a large pattern change. Treat each access point, pipe, control box and obstacle as its own record. The example below illustrates notation only; it is not derived from a real customer order.
Top plan · location by X/Y coordinatesEXAMPLE NOTATION
The coordinates that matter
Every feature gets a location and a function.
Record both the physical measurement and the reason a pattern feature is required. For a cover that is removed daily, a control-panel opening may matter more than a minor surface projection.
Recommended photo set
- Front and rear elevations
- Left and right elevations
- Top / roof, if safe and accessible
- Detail photos of each P-numbered projection
- Tie-down locations and high-wear contact zones
Project drawing convention: Include a scale/reference item in photos, but never use photo pixels as the controlling dimension. Include units and drawing revision.
| Field | What to write | Why it matters for fabrication |
|---|---|---|
| Feature ID + face | P1 / top; P2 / right; A1 / access panel | Connects the top view, elevations, photos and pattern annotations. |
| Location (X / Y / Z) | Distances from common datum, using one stated unit | Prevents mirrored placement and uncertain cut-out positions. |
| Physical size | Width, height, projection, radius / slope if relevant | Determines box-outs, relief panels and material travel distance. |
| Functional requirement | Cover fully / leave open / inspection flap / separate boot | Distinguishes surface coverage from necessary access and ventilation. |
| Local condition | Sharp edge, hot surface, abrasion, load, water flow | Flags safety review, wear patches and seam routing. |
| Verification | Photo reference, field check initials, revision | Makes the design traceable before sample and bulk approval. |
Shape-based selection
Choose a cover architecture before finalizing measurements
An oversized rectangular tarp is not always the right response to unusual geometry. The appropriate approach depends on protection, drainage, ease of handling, frequency of access and whether the same equipment model will be covered again.
01
Stepped housings
Measure each elevation change, step depth and transition radius. A shaped panel may reduce unsupported fabric, especially around a raised motor housing.
02
Curved tanks & roofs
Provide cross-section profiles and arc lengths along the fabric route. Flat chord length alone can underestimate the cover path.
03
Pipes & exhaust stacks
Measure the center location, outside envelope and interface condition. Seek a special design review; do not drape ordinary PVC fabric over hot exhaust.
04
Unequal-height sides
Measure drops independently from the proposed seam or high line to the actual lower-edge location on each face.
05
Doors & service panels
Record opening limits, swing direction and access frequency. A zipper or flap is not useful if its location conflicts with a handle or hinge.
06
Multiple connected zones
Consider sectional covers when a single fitted tarp would be too heavy, difficult to lift or awkward to route around fixed obstacles.
For heavy construction equipment with booms, cabins and counterweights, see DERFLEX's heavy machinery tarp cover options. The material supplier and finished-cover maker should review geometry and attachment loads together.
Factory translation
How field dimensions become an industrial tarp pattern
Material and manufacturing choices change the finished cover geometry. The buyer should approve the intended fit, while the fabricator plans raw panels, welding routes, hems, reinforcement and assembly order around the actual coated fabric.
| Design decision | What the measurement drawing must show | Production consideration |
|---|---|---|
| Flat vs semi-fitted vs fitted | Station profile, unequal drops, desired ease and installation sequence | Simpler covers allow more flexibility; exact-fit multi-panel covers need greater drawing precision. |
| PVC coated polyester | Outdoor exposure, handling frequency, folding, wear areas and expected duty | Review fabric weight, coating, flexibility and reinforcement. Use DERFLEX PVC tarpaulin material as a sourcing reference, not a universal one-grade specification. |
| Welded / sewn seams | Panel breaks, bend transitions, drainage direction, required waterproof joints | Seam width and cut allowance depend on fabric and process; confirm after material and pattern review. |
| Edge reinforcement | Finished lower line, corner locations, tie-down direction, rubbing points | Webbing, hems, corne, r patches and local abrasion layers should follow actual load and contact zones. |
| Hardware and access | Measured anchor centers, strap reach, closure direction, opening perimeter | Fastener rows and zippers must be aligned to reachable, suitable supporting features. |
| Repeat-production control | Named units, datum, drawing version, fit definition and inspection method | Set the agreed finished-size tolerance and sample approval process for dimension-critical repeat programs. |
For custom conversion and OEM programs, DERFLEX can discuss custom tarp manufacturing and finishing options based on the approved project drawing. Specific size tolerance, construction and material availability are subject to quotation review.
Illustrative workflow / No invented customer claim
Worked example: a stepped compressor with an offset pipe
Imagine a stationary compressor with a tall service housing on one side and a pipe rising above its main roof. It would be inaccurate to choose a finished tarp only from its nominal base footprint. The right package would capture:
A / ENVELOPE
Largest outside size
Overall length, width and total height in the actual parked condition.
B / PROFILES
Step transition
Horizontal location of the height change and sloping transition length.
C / PENETRATION
Raised pipe
Pipe center, projection and whether it can safely be included or must remain open.
D / USE
Access & retention
Door swing, cover-removal route, safe anchor points and required ventilation.
The proposed result might be a semi-fitted multi-panel cover, a simple draped cover with a separate weather hood, or a sectional enclosure. The choice depends on safety, operating state, use frequency and fabrication review—not on an arbitrary fixed clearance figure. Buyers protecting stored equipment can also review industrial storage tarp applications.
Quotation toolkit
Send an RFQ the production team can actually use.
A production-ready inquiry links geometry to the material and service conditions. Include a labeled drawing and photos, the required finished cover behavior, and the intended quantity. There is no submission form on this page; the quote button opens the official DERFLEX request page.
Field-to-factory approval checklist
- 01 / Asset — Equipment type, model and parked configuration
- 02 / Geometry — L, W, H envelope, profile stations, slopes and arc paths
- 03 / Datum — Origin, X/Y/Z directions and all feature coordinates
- 04 / Function — Access, drains, cables, vents and safety exclusions
- 05 / Fixing — Anchor centers, lower edge, straps, D-rings and reinforcement
- 06 / Fabric — PVC material direction, color, performance, handling duty
- 07 / Drawings — Dimensioned views, marked photos, units and revision
- 08 / Commercial — Quantity, OEM branding, packing, destination, required tests
For repeat programs, review an approved sample and agree how final dimensions will be checked before bulk fabrication. Explore made-to-measure tarpaulin programs.
Copy-ready custom equipment cover brief
Replace the bracketed fields. This brief is a starting point; your dimensioned drawing remains the fabrication reference.
PRODUCT: Custom industrial equipment tarp / fitted cover EQUIPMENT: [type, model, parked configuration] APPLICATION: [outdoor idle storage / other approved use] DATUM: [origin location and X / Y / Z convention] OVERALL ENVELOPE: L [ ] × W [ ] × H [ ] [units] PROFILES: [station IDs, heights, slopes, curved paths] PROTRUSIONS: [feature schedule + coordinate drawing] ACCESS / SAFETY: [flaps, no-cover zones, ventilation] FINISHED COVER: [desired fit, lower edge, functional drop] FASTENINGS: [anchoring points, straps, eyelets, D-rings] FABRIC: [preferred PVC specification, color, performance] ORDER: [quantity, branding, packing, destination] ATTACHMENTS: [drawing revision and labelled photos] REQUEST: Confirm pattern, finished-size tolerance, seam layout and sample approval before production.
You can also select and copy the text manually.
FAQs / Buyer decisions
Questions buyers ask before pattern approval
Practical answers for machine builders, importers, procurement managers and tarp fabricators specifying made-to-measure equipment covers.
How do you measure irregular equipment for a custom tarp?
Measure the maximum machine envelope in its covered condition, establish a fixed datum, then document profile stations, curved fabric paths, protrusions, openings and safe fixing points. Send top, side and detailed dimensioned views with labelled photos. The finished cover design is then reviewed against these measurements.
Is length × width × height enough for a fitted machinery cover?
No. Those dimensions only describe the outer envelope. Raised housings, curved surfaces, projecting pipes, service doors, clearance and fastening locations can all change the cover pattern. A fitted cover needs the extra geometry recorded on a drawing.
How should I measure an arched or curved machine housing?
Mark measurement stations and use a flexible tape to follow the route where the fabric must pass. Record the arc or slope path separately from the straight horizontal projection, and provide at least one cross-section that shows the profile.
How much clearance should a custom equipment tarp have around protrusions?
There is no universal allowance. Required clearance depends on the projection, cover architecture, handling access, water shedding and any safety restrictions. Define the functional need and ask the fabricator to confirm the designed clearance and finished pattern. Hot exhaust and operating ventilation need separate technical review.
Should I specify cut size or finished cover size?
Specify the measured machine geometry and intended finished cover size or approved fitted pattern. The fabricator should calculate raw cut panels, seam overlap and hems based on the selected fabric and construction method. Agree the finished measurement condition and tolerance before approval.
Can I cover equipment while it is operating?
Do not assume a standard PVC storage tarp can be used over operating equipment. Heat, exhaust, electrical access, cooling airflow and moving components may make a conventional cover unsafe. Follow the equipment manufacturer's directions and obtain an engineered operating enclosure where required.
What photos and drawings help DERFLEX prepare a custom tarp quotation?
Include front, rear, left, right and safe top-view photographs; detail images for marked projections and tie-downs; top and side dimension drawings with a datum and units; profile sections; and the quantity, service condition, material direction and required finished fit.
From field measurements to repeatable supply
Have a difficult machine profile? Send us the drawing.
DERFLEX supports PVC coated fabric sourcing and custom tarp manufacturing discussions for OEMs, fabricators and industrial project buyers. Share the equipment geometry, marked photos, use conditions, quantity and target material so the team can review the practical cover construction before quoting.
Custom dimensionsWelded seamsReinforcementOEM programs
Request a Quote →
Official DERFLEX quotation page. Materials and fabrication details are confirmed per project.