Anti-Bird Netting Specifications: What to Put in Your RFQ

A specification for anti-bird nettings is only useful if it is unambiguous to someone who cannot see your project. Most disputes on this product do not come from bad manufacturing — they come from a drawing that could reasonably be read two ways, where the supplier read it the cheap way and the buyer read it the expensive way.

This is a practical specification checklist, written around what the standards actually require.

The three specification families you will meet

Suppliers will quote against whichever family your market uses, and the part can usually be built to any of them:

• ISO 4892-3 — UV ageing of the monofilament.
• ISO 1806 — netting mesh breaking force test method.
• EN 12637 reference — indoor flame-retardant netting classification context.

The mistake is to specify a standard reference without specifying the class or grade within it. If you write only the standard number, the supplier will quote the lowest class that satisfies it. Write the standard and the level you want.

Dimensional data that has to be on the drawing

For this product the critical dimensions are: mesh 19 / 28 / 50 / 75 mm; twine Ø 0.8–1.5 mm; panels made up to order, common rolls 5×50 m and 10×50 m.

Three rules that prevent most dimensional disputes:

1. Give tolerances on every functional dimension, not just the nominal values. A nominal dimension with no tolerance is legally “as the supplier chooses”.
2. Say which dimensions are functional and which are cosmetic. Suppliers prioritise what you prioritise, and they cannot guess.
3. State the gauge or measuring method where a dimension is critical. Two inspectors with different methods will disagree about the same part.

Material and grade

The base specification is UV-stabilised HDPE monofilament, knotted or knotless, with a perimeter rope. Grades commonly offered include:

• HDPE knotless (standard)
• HDPE knotted (heavy duty, gull pressure)
• flame-retardant grade for indoor use
• stone-coloured, black or translucent

Ask the supplier to state the grade on the quotation, not on an assumption. Grade substitution is the single most common silent cost reduction, and it is usually invisible in the finished part — a 201 stainless component looks exactly like a 304 one until the second winter.

Surface treatment

The usual finish for this product is colour through the monofilament — black hides best, stone blends with masonry, translucent for glass atria.

Two points worth writing into the order:

• A measured requirement, not a process name. “Hot-dip galvanised” is a process; “70 µm minimum, tested by coating mass on three parts per batch” is a requirement.
• What happens at cut edges and drilled holes, if any. These are where coatings are habitually broken and where corrosion starts.

Type tests and routine tests

These are different things and are frequently confused in quotations:

• Type tests qualify the design once. On this product: mesh breaking force per ISO 1806; UV ageing 3000 h with strength retention ≥ 90 %; knot slippage check after load cycling.
• Routine tests are run on every batch: mesh size audit (pigeon exclusion needs ≤ 50 mm; sparrow ≤ 28 mm).

Specify which type-test reports you want supplied as documents, and which routine test results must accompany each shipment. On a first order, ask for the type-test report before you place it.

The failure modes your specification should be closing

• Net failing within two seasons — no genuine UV package; recycled HDPE looks identical on the roll and is gone in 18 months of sun
• Birds pushing through at fixings — perimeter rope too thin or fixing pitch too wide; the net bellies away from the cable and birds enter at the gaps
• Sagged panels — installed without a perimeter cable; the net stretches and sags, and pigeons walk it like a trampoline

Each of these can be turned into one line in the specification. That is the real purpose of writing it out: not bureaucracy, but making the specific failure you are worried about somebody’s explicit responsibility.

A specification skeleton you can reuse

1. Scope: Anti-Bird Netting to be supplied as bird net, pigeon netting, anti-bird net, HDPE bird netting, knotted bird net.
2. Dimensions and tolerances: mesh 19 / 28 / 50 / 75 mm; twine Ø 0.8–1.5 mm; panels made up to order, common rolls 5×50 m and 10×50 m.
3. Material: UV-stabilised HDPE monofilament, knotted or knotless, with a perimeter rope; grade HDPE knotless (standard) or better.
4. Standard: ISO 4892-3 — UV ageing of the monofilament; ISO 1806 — netting mesh breaking force test method; EN 12637 reference — indoor flame-retardant netting classification context.
5. Finish: colour through the monofilament — black hides best, stone blends with masonry, translucent for glass atria.
6. Tests: mesh breaking force per ISO 1806; UV ageing 3000 h with strength retention ≥ 90 %; knot slippage check after load cycling; mesh size audit (pigeon exclusion needs ≤ 50 mm; sparrow ≤ 28 mm).
7. Marking and packing: rolls in woven bags; made-up panels folded with the perimeter rope tagged per corner.
8. Inspection: pre-shipment, against this specification, with photo evidence and test records.

Related: the anti-bird netting quality inspection checklist turns this specification into an inspection plan you can hand to a third-party inspector.