Sarking, wall wrap and insulation board are all held up by something small that gets ordered last, and the choice comes down to one number: how wide the fastener presses on the material. A Stinger staple crown is 9.5 mm. An Ametalin cap nail cap is 25 mm. Kingspan will not accept anything under 35 mm on a concrete soffit. That is the whole argument, in numbers rather than adjectives.
In short
- Cap against plain is a question of face width: 9.5 mm for an A-11 staple crown, 25 mm for a cap nail, 45 mm for a Bradfix washer.
- Only two fixing centres are published in our whole catalogue: Ametalin's 300 mm on a cavity wall and 150 mm direct to stud, and Bradford's 300 mm maximum for the Plasti-Grip washer.
- On an ICCONS fastener the size on the box is the board thickness, not the pin length. The head is 60 mm on every size they publish, and the 45 mm we stock is not on their sheet.
- Tool, fuel cell, pin, washer and magnetic adaptor are one system. Leave one out and the job stops.
- Almost nothing here carries a published pull-out figure, and this article says so where it does not.
Most of this blog is about the material. This page is about what holds it on. A roofing blanket has its own sequence, in installing a roofing blanket.
Fixed to what, with what
Fixings organise by what is fixed to what. That pair picks the fastener, and the fastener picks the tool.
| What you are fixing | To what | Fastener | Tool | Also needed |
|---|---|---|---|---|
| Sarking, wall wrap, permeable membrane | Timber framing | Ametalin Cap Nails, 25 mm cap on a 25 mm ring shank nail | Hammer | Nothing else |
| Sarking, wrap, roofing felt, rolled insulation | Timber framing | Stinger A-11 staple, 3/8 inch (9.5 mm) crown | Stinger HT38 hammer tacker | Staples by the 5000 box |
| Sarking, wall wrap, insulation | Steel framing | Gripshank Supersharpy 22 mm break away pin with a GTW25 25 mm steel washer | ICCONS ST3025C gas pin nailer | GTMA-25W-SN magnetic adaptor, fuel cell |
| Wall wrap | Steel framing | Bradfix Plasti-Grip washer, 45 mm | Screw gun | 8 to 10g countersunk self drilling screw |
| Sarking or wrap, without penetrating | Steel framing | Trade Select Double Sided Fixing Tape, 38 mm x 50 m | None | Clean dry stud, squeegee or roller |
| Rigid insulation board | Concrete soffit or wall | ICCONS ballistic point insulation fastener, sized to the board | ICCONS GTIXF-160C gas nailer | GT-IXF fuel cell |
| Underfloor batts | Timber floor joists | Bradford Optimo saddle or strap | Stapler for saddles, screws or nails for straps | Bradford Optimo batts only |
The number that decides it
A membrane does not fail in the middle of the sheet. It fails at the fixing. A plain staple clamps a 9.5 mm strip between two thin legs, so the wind load off a square metre arrives at two slits and the flapping lengthens the tear. A cap or a washer takes it across a disc. Nobody publishes that comparison, so here it is.
| What holds it down | Face diameter | Substrate | Published spacing rule | Source |
|---|---|---|---|---|
| Plain A-11 staple crown | 9.5 mm (3/8 inch) | Timber | None published | Stinger HT38 sheet |
| Ametalin cap nail cap | 25 mm | Timber | 300 mm on a cavity wall, 150 mm direct to stud | Ametalin APM-45726-9 |
| ICCONS GTW25 steel washer | 25 mm | Steel | None published | Our catalogue only |
| Bradfix Plasti-Grip washer | 45 mm, 5 mm high | Steel | 300 mm maximum | Bradford PTS0128 Issue B |
| ICCONS ballistic point fastener head | 60 mm | Concrete | 100 mm minimum spacing and edge distance, 4 per m² on cut panels | ICCONS TDS 4002.5 |
| Kingspan minimum for a K10 G2 soffit board | 35 mm minimum head | Concrete | Set by Kingspan's own fixing schedule | ICCONS TDS 4002.5 |
Ametalin put the same argument as a ratio: the cap nail gives "over and above 20 x the holding power of plain nails or staples". No kilonewton figure, no test standard, no comparison staple named.
Timber: cap nails and staples
A 25 mm impact resistant polymer cap, reinforced into a cup shape, sits on a 25 mm ring shank galvanised nail, collated in strips of ten, 25 strips to a box of 250, with end tabs so the last nail can still be driven.
The centres are the only ones a membrane maker in our catalogue publishes for a cap or nail fixing: 300 mm for timber framed cavity walls, 150 mm direct to stud, fixing done before cladding. Picking the wrap comes first, and that is choosing wall wrap and sarking. On foam core products such as Ametalin ThermalBreak the nails should not completely compress the board, or no thermal break is left at the fixing.
Where they earn their place is a frame that stands wrapped for a while: Ametalin say the large cap reduces blow-offs and lateral slippage where membranes are exposed for extended periods. A box of 250 at 300 mm centres covers about 75 m of stud line.
The Stinger HT38 hammer tacker
A hammer tacker sets the staple with the weight of the swing instead of a spring, so a wrap goes up faster. Stinger's sheet for the HT38, item #0136450, is one page: roofing felt and rolled insulation with staples only, magazine holding 168 of the 3/8 inch (9.5 mm) 20 gauge staple. The staples are better documented than the tool, at A-11 galvanised chisel point, 5000 to a box, to ASTM F1667, though RM Industries call the same item a 10 mm crown in 21 gauge.
Steel: pins, washers or no holes at all
Steel has no fibre to grip. Three methods.
Gas driven pins with washers
The ICCONS ST3025C is a gas actuated break away pin nailer firing Structnail Gripshank Supersharpy 22 mm pins, code SNS2229DG. Gripshank is the ringed shank that stops the pin backing out of steel, Supersharpy the point that drives without a pilot hole. A GTW25 25 mm steel washer, 250 to a pack, then holds a membrane across the same 25 mm face a cap nail gives on timber.
A GTMA-25W-SN magnetic adaptor holds the washer square on the nose while the pin fires, so the fixing is one action rather than a washer held overhead with one hand.
None of those four items carries a data sheet, and ICCONS TDS 4002.5 does not mention Structnail at all. No pull-out figure, no base steel thickness range, no spacing, no membrane schedule. Take the spacing from the membrane maker, and get a figure from ICCONS in writing before specifying.
Bradfix Plasti-Grip washers on a screw
The washer under a screw needs no gas tool. Bradfix Plasti-Grip is polypropylene, 45 mm across and 5 mm high, 1000 to a box, code 136770, cupped underneath to seal around the membrane. Three rules matter more than the dimensions: 300 mm maximum spacing, a countersunk self drilling screw of size 8 to 10g, and tightening only enough to press the perimeter down. Bradford name AS 4200.2 and say no NCC clauses apply.
Bradford state plainly that the product is untested for high wind pressure and not designed for prolonged exposure, with anything left more than 6 weeks inspected for damage. Supplier copy, ours included, has called these a high wind fixing, and the maker's limitations do not support it.
Tape, and no penetration at all
The Ametalin cap nail page sends you here for steel framing. Trade Select Double Sided Fixing Tape is a 38 mm x 50 m roll that fixes a membrane to a steel stud with no penetration at all. The stud has to be clean and dry, and Ametalin do not recommend it under a hot metal roof. Full specification in which insulation tape.
Concrete soffits and the gas tool system
Fixing rigid board to a concrete soffit is where the word system stops being marketing. The GTIXF-160C is a light weight gas nailer ICCONS describe as designed for fastening insulation from 25 mm to 120 mm, and the gas is the GT-IXF-24+ cell, listed only as a fuel cell for it. On licensing our sources disagree: ICCONS list "No License" among the tool's features, while our product pages say operators should be trained and licensed as their state requires.
The number on the box is the board thickness
This catches anyone used to buying nails by length. A GTIF050 is not a 50 mm pin. It is the fastener for 50 mm insulation, and the head is 60 mm across on every size ICCONS publish.
| Part number | Insulation thickness (mm) | Head diameter (mm) | Inner carton | Outer carton | Stocked |
|---|---|---|---|---|---|
| GTIF025 | 25 | 60 | 50 | 1000 | Yes |
| GTIF030 | 30 | 60 | 50 | 1000 | Yes |
| GTIF035 | 35 | 60 | 50 | 1000 | No |
| GTIF040 | 40 | 60 | 50 | 1000 | Yes |
| GTIF045 | 45 | Not published | 50 (our pack) | 18 packs (ours) | Yes |
| GTIF050 | 50 | 60 | 50 | 900 | Yes |
| GTIF060 | 60 | 60 | 50 | 800 | Yes |
| GTIF075 | 75 | 60 | 25 | 600 | Yes |
| GTIF080 | 80 | 60 | 25 | 600 | Yes |
| GTIF090 | 90 | 60 | 25 | 600 | Yes |
| GTIF100 | 100 | 60 | 25 | 500 | Yes |
| GTIF120 | 120 | 60 | 25 | 400 | No |
Every figure there is the ICCONS one except the 45 mm row, which is ours, because ICCONS have no 45 mm part: its head diameter is nowhere and its pack data comes from the RM Industries price list of May 2026. That list also disagrees at 75, 80 and 90 mm, where our pack figure is 50 against an inner carton quantity of 25, so check the pack size on the order. ICCONS stop at 120 mm while our product page puts the manufacturer range at 130 mm. Colours are White, Black and Grey, and copy calling the standard one clear is wrong.
In concrete of 15 to 50 MPa, ICCONS publish a 100 mm minimum spacing and edge distance and a recommended tensile resistance of 0.15 kN for all GTIF sizes, with at least four fixings per square metre on cut panels. That 0.15 kN is the only published holding figure on this page. How many go into a whole board is the board maker's schedule, set out for a K10 G2 soffit board in soffit insulation board.
Holding batts up under a floor
Under a suspended floor the enemy is gravity rather than wind, and friction alone lets batts sag and drop unseen.
Optimo Saddles give a stable base in new builds, go up by staple fixing, and suit 45 mm framing only. Optimo Straps are aluminium, are made for existing homes, and take galvanised screws or nails. Spacing is evenly distributed, with a minimum of two supports on each side of each batt. Both come 250 to a box for R2.5 at 90 mm, codes 96262 and 95295, covering 53 m² against 415 mm batts or 75 m² against 565 mm. Straps conduct electricity, so power gets isolated first. The rest is in underfloor insulation for a suspended floor.
What nobody publishes
This section exists because the alternative is inventing numbers.
- Cap nails have no pull-out figure at all. Ametalin publish only the claim of over 20 times a plain nail: no kilonewtons, no test standard.
- The Structnail system has nothing between its four parts. Tool, pins, washers and adaptor share no data sheet: no steel thickness range, no tensile value, no spacing. The Bradfix washer has no pull-out figure either.
- Staple leg length by substrate is unpublished. The Stinger staple is a 3/8 inch leg and nothing tells you what hardwood needs against pine.
- Only two fixing centres exist in the whole catalogue, Ametalin's and Bradford's. Nothing we hold cites an Australian product standard for a cap or a washer.
What goes wrong
- Plain staples on a frame that will stand exposed. 9.5 mm of crown against a whole sheet of wind.
- Cap nails ordered for a steel frame. They are nails, for timber. Steel takes a gas pin and washer, a washer under a screw, or tape.
- Over-tightening a Plasti-Grip washer, or driving a cap nail so hard it crushes a foam core. Both remove what you paid for.
- The concrete fastener ordered by pin length. The number on the box is the board thickness.
- Buying the gas tool without the magnetic adaptor. A washer held overhead with one hand is not a method.
- Wrap left up for months on a Bradfix washer. Bradford put a 6 week inspection point on it.
We supply it, and we install batts, wall wrap and sarking
AWBM stocks the fixings as well as the membranes and boards they hold: cap nails, hammer tackers and staples, gas tools, pins, washers, fixing tape and sub-floor saddles and straps. Delivery in Victoria and New South Wales is $55 in metro Melbourne and metro Sydney, $99 in the outer suburbs and $149 anywhere else, set by postcode. Send the frame type and how long it stands before cladding.
Or browse accessories, building membrane and commercial insulation.
Frequently asked questions
What holds sarking, wall wrap and insulation in place?
It depends on the substrate. On timber, cap nails or staples from a hammer tacker. On steel, a gas driven pin with a steel washer, a plastic washer under a self drilling screw, or double sided tape. On concrete, a ballistic point fastener sized to the board and fired from a gas nailer.
How far apart do Ametalin cap nails go?
Ametalin specify 300 mm centres for timber framed cavity walls and 150 mm for direct to timber stud, with fixing done before the cladding goes on. A box of 250 covers roughly 75 m of stud line at 300 mm centres, and direct to stud doubles that.
Why not just staple the wrap on?
Face width. A Stinger A-11 staple clamps a 9.5 mm strip of membrane between two thin legs, and the wind load off the whole sheet arrives at those slits, where the tear starts. A cap nail spreads it across a 25 mm cap and seals the penetration. Ametalin claim over 20 times the holding power of a plain nail, with no test figure behind it.
What are insulation pins?
The term covers two things. Searches for insulation pins often mean stick pins, hangers, skewers or spindles for ductwork and plant insulation, which we do not stock. What we stock are gas driven pins: 22 mm Gripshank Supersharpy break away pins for steel, and ballistic point fasteners for concrete.
What size insulation fastener do I need for a 50 mm board?
A GTIF050. The number in an ICCONS code is the insulation thickness, not the pin length, so you order against the board. The head is 60 mm on every size ICCONS publish, though the 45 mm we stock has no row on their sheet and no head diameter. Their sheet runs 25 to 120 mm; we stock 25 to 100 mm.
How do you fix insulation board to a concrete soffit?
With a ballistic point fastener sized to the board, fired from a gas nailer such as the ICCONS GTIXF-160C: push it through until the head is flush, then pull the trigger. ICCONS publish a 100 mm minimum spacing and edge distance in 15 to 50 MPa concrete, a recommended tensile resistance of 0.15 kN and four fixings per square metre on cut panels. The count for a full board comes from the board maker.
Do I need a licence to use a gas nailer?
Our sources disagree, so check rather than taking either one. ICCONS list "No License" as a feature of the GTIXF-160C, the usual distinction between a gas tool and an explosive powered one. Our product pages say operators should be trained and licensed as their state requires. The tool manual and your state regulator settle it.
Can I fix wall wrap to a steel frame without making holes?
Yes, with double sided fixing tape. Ametalin's Trade Select roll is 38 mm x 50 m, runs up the stud and holds the wrap with no penetration. The stud has to be clean and dry, because moisture costs adhesion, and it is not recommended under a hot metal roof.
Sources
- Ametalin Cap Nails technical data sheet, APM-45726-9, 2024. Configuration, fixing centres, the holding power claim, the foam core caution.
- Stinger HT38 Hammer Tacker data sheet, items #0136450 and #0940042, from RM Industries, no issue number or date printed. Tool and staple specification.
- ICCONS Insulation Solutions technical data sheet TDS 4002.5, PDF created 4 July 2024. The GTIF table, concrete performance, tool and fuel cell.
- Bradford Product Technical Statement, Bradfix Plasti-Grip Washer, PTS0128_B, Issue B, no date printed. Dimensions, spacing, screw rules, AS 4200.2 and the limitations.
- Bradford Product Technical Statement, Bradford Optimo Fixing Products, PTS036_B, Issue B, no date printed. Saddles and straps, support spacing, coverage, codes.
- Ametalin technical data sheet for Trade Select Double Sided Fixing Tape, TPM-45937-0, copyright 2025, no issue date printed. Roll size and the hot metal roof warning.
- AWBM catalogue product data read 23 September 2026, and the RM Industries price list of May 2026 cited inside it, for codes and pack quantities.
General information, current at the date shown. It does not set the fixing schedule for your job: that comes from the manufacturer's instructions and, where wind load governs, from a design professional. Several products here carry no data sheet at all, and that is stated where it applies. Specifications change without notice.