Description
Mechanical fixing on timber-frame and steel substrates needs a different approach from masonry hammer-in plugs: the screw provides pull-out resistance, and the disc spreads clamping force across the insulation face. The TD60 is the standard collar for exactly these substrates, paired with a galvanised steel screw sized to the board build-up.
What Universal PVC Discs TD60 Do in a Timber-Frame EWI System
Universal PVC Discs TD60 are 64 mm polypropylene fixing collars that clamp EPS, XPS, and mineral wool boards to timber-frame, OSB, plywood, cement-board, and steel-sheet substrates using a separately specified galvanised steel screw. They are the standard mechanical-fix solution where hammer-in masonry plugs cannot grip, stocked within the EWI fixing accessories range at Renders World. Each 100-piece bag covers roughly 12–17 m² at the typical 6–8 fixings per square metre — enough to match one bag to a single domestic elevation.
The disc sits at the interface between the screw head and the board face. Without it, even a wide-headed timber screw would cut through soft EPS or compress mineral wool fibres locally, shedding clamping force within hours. With the collar in place, the 64 mm face distributes load across roughly 32 cm² of board — and that distribution is what holds the system against UK wind suction over a 25-year typical service life.
- On the board — the wide collar spreads clamping force across the insulation face, preventing localised pull-through under wind suction and thermal cycling.
- On the substrate — one disc covers timber studs, OSB, plywood, cement board, and steel sheet, so mixed-substrate properties stock a single collar SKU.
- On the finish — countersunk and capped, the disc leaves a continuous board face that the basecoat covers without a telegraphed bump at each fixing.
Why Trade Specifiers Choose TD60 PVC Discs
- 64 mm collar for genuine load distribution — the wide face spreads clamping force, preventing pull-through under wind suction, thermal cycling, and dead-load over the service life.
- Universal substrate compatibility — one disc covers timber studs, OSB, plywood, cement board, and steel sheet, keeping site stock simple on mixed-substrate properties.
- Fits every insulation thickness on the range — because the screw is chosen separately, the same TD60 fixes 30 mm reveal panels through to 200 mm boards from the graphite EPS insulation range without changing SKU.
- Polypropylene durability — resists UV during the open-scaffold phase, tolerates alkaline basecoat chemistry, and holds its geometry from −20 °C to +80 °C.
- Low thermal bridging at each fixing — the polymer collar carries a fraction of the thermal short-circuit of an all-metal fixing, helping in-service U-value match the calculation.
- 100-piece trade pack — one bag matches one typical elevation at 12–17 m², keeping quote-stage arithmetic simple.
Technical Specifications — TD60 Data Sheet Highlights
| Property | Value |
|---|---|
| Disc designation | TD60 (TDP-060 type) |
| Disc diameter | Approx. 64 mm (60 mm nominal) |
| Material | Polypropylene |
| Pack quantity | 100 pcs |
| Compatible insulation | EPS (white and graphite), XPS, mineral wool |
| Compatible substrates | Timber studs, OSB, plywood, cement board, steel sheet |
| Screw type | Galvanised steel — sold separately, length matched to thickness |
| Typical fixing density | 6–8 per m² |
| Coverage per pack | Approx. 12–17 m² at standard density |
| Service temperature range | −20 °C to +80 °C |
The 64 mm collar is the standard supplementary bearing face across screw-fixed EWI systems on non-masonry substrates. Confirm the specific screw length against the actual build-up before ordering screws in volume.
How TD60 Discs Install in a Timber-Frame or Steel Build-Up
On a timber-frame property the workflow is adhesive-first, mechanical-second. Boards are bonded to the OSB or plywood sheathing with a styrofoam adhesive, left to cure for the specified period, and then mechanically secured. At each fixing point the TD60 sits flat against the board face, a galvanised steel screw passes through the central hole, and the screw drives into the timber or sheathing behind to clamp the assembly — so the disc does its work the moment the driver stops.
Stud spacing rarely aligns with every point on a 6-per-m² grid. Mid-board fixings landing on sheathing alone still contribute clamping force, but perimeter fixings should engage solid timber wherever the layout allows, because the corners and edges carry the wind load and stud-engaged fixings out-perform sheathing-only fixings on pull-out.
- Screw length — insulation thickness + adhesive bed (~5–10 mm) + minimum 25–30 mm embedment into structural timber or steel.
- Edge distance — position fixings at least 100 mm from board edges to prevent splitting and stress concentration.
- Density — 6 fixings/m² for EPS · 8 fixings/m² for mineral wool · increase at corners, parapets, and upper storeys per wind-load calculation.
- Driver setting — cordless impact or drill with adjustable clutch; set torque so the disc pulls flush without crushing the board.
For full step-by-step coverage including substrate assessment and corner-zone detailing, the complete EWI fixings installation guide takes the method end to end. To work out exact fixing counts by wind zone, building height, and substrate, the fixing pattern and spacing calculation method runs through the maths with worked examples.
Installation Notes — Screw Selection, Torque, Countersinking
Screw length is the variable that catches first-time TD60 users out. A 50 mm graphite EPS board fixed to 11 mm OSB over a timber stud needs a screw long enough to pass through 50 mm of insulation, 5–10 mm of adhesive bed, the OSB layer, and reach a minimum 25 mm embedment into the stud — typically a 90 mm screw for that build-up. The same disc paired with a 150 mm board moves the screw to roughly 190 mm. Calculate against the actual build-up before ordering in volume.
Driver torque matters as much as length. Over-driving embeds the disc below the face and cuts the clamping area; under-driving leaves it proud, telegraphing through the basecoat under raking light. A cordless drill with an adjustable clutch settled at a moderate value — confirmed on the first board of the day — keeps every fixing consistent without re-checking each one. On mineral wool slabs the surface fibres compress slightly under the disc, which is normal: the 64 mm collar still distributes the full clamping load across its footprint.
Where a flush finish under the basecoat is required, each disc can be countersunk with the EPS and wool hole cutter and capped with a grey EPS plug cap to restore the continuous insulation surface. This is standard on darker render finishes, where any thermal anomaly shows through after the first cold morning.
What UK Installers Do Differently With TD60 Discs
The discs are simple hardware, but consistency across a full elevation comes down to three habits experienced timber-frame installers share — and they show in the finish long after the scaffold comes down.
- I always set the driver clutch on the first board of the day and leave it alone. Five test fixings into an offcut confirm the torque pulls the disc flush without crushing the board; after that, the setting holds across the whole elevation.
- I always chalk-line the fixing grid before driving any screws. Marking the 6-per-m² pattern keeps the discs in a regular array, so the caps land in line and the finish reads clean across the wall.
- I always pair the TD60 bag with a matched count of screws and caps. A bag of 100 discs without 100 screws to hand is a half-day site stop; order screws by length once the build-up is fixed.
- I always favour perimeter fixings into solid timber. The corners and edges carry the wind load, so keep those on stud wherever the layout allows.
Is the TD60 Disc Right for Your Project?
- For timber-frame, OSB, and steel-sheet EWI installations — the TD60 is the standard mechanical-fixing collar where hammer-in masonry plugs cannot grip; specify it across the elevation and size screw length to the build-up.
- For a flush, render-ready surface — pair the disc with the EPS hole cutter and grey EPS plug caps to countersink each fixing and restore the continuous insulation face under the basecoat.
- For masonry walls instead — brick, block, concrete, and stone take the LTX hammer-in plug range from the fixing accessories collection, where the plug expands into the substrate without a separate screw.
- For mineral wool slab systems on timber frame — the TD60 works directly with Rockwool mineral wool slabs; increase density to 8 per m² for slab weight and confirm screw length covers full slab depth plus embedment.
FAQ — TD60 Coverage, Compatibility, Ordering
Are the screws included in the 100-piece pack?
No. The pack contains 100 disc collars only. Galvanised steel screws are selected separately based on insulation thickness and substrate embedment. This is the design intent — one disc SKU covers every thickness from 30 mm reveal boards to 200 mm deep-renovation panels, with the screw chosen to suit the build-up.
How many TD60 fixings do I need per square metre?
The standard density is 6 fixings per m² for EPS and XPS, rising to 8 per m² for mineral wool to handle the slab's higher weight. Corners, parapets, eaves, and upper storeys typically need a denser pattern confirmed by a project-specific wind-load calculation under BS EN 1991-1-4. A 100-piece bag covers roughly 12–17 m² at standard density, lining up with one typical domestic elevation.
Can I use TD60 discs on masonry walls?
The TD60 is designed for screw-fixed applications into substrates where a thread engages directly — timber, OSB, plywood, cement board, and steel sheet. On masonry, the LTX plug range provides an integrated disc and expansion mechanism in one component, which suits brick, block, concrete, and stone better than a separate disc-plus-screw combination.
Do the discs have to be countersunk?
Countersinking is not structurally required — the disc clamps correctly when seated flat against the face. It does eliminate the thermal bridge at each fixing and produces a smoother surface for the basecoat, which matters on dark renders where any anomaly shows through. On projects specifying a premium rendered finish, countersinking every fixing is best practice and is required by several EWI system certifications, subject to the specific system holder's guidance.
How do I calculate the right screw length for a TD60?
Add the insulation thickness, the adhesive bed (5–10 mm), and a minimum 25–30 mm embedment into structural timber or steel. A 100 mm EPS board on 11 mm OSB over a timber stud needs roughly a 140–150 mm screw to cover board, adhesive, sheathing, and embedment. Always verify on the actual build-up before ordering volume — an extra 10 mm of embedment is cheap insurance against pull-out.
Will the TD60 compress mineral wool too much?
Light surface compression of the fibres under the disc is normal and does not affect clamping — the 64 mm collar distributes load across its footprint, and the slab's body density carries the clamping force without further compression. If a fully flush face is required, countersink the disc and cap it to restore the surface profile under the basecoat.
What happens to the discs at end of life?
Polypropylene is recyclable through standard plastics recovery streams when the system is eventually stripped at demolition or refurbishment. The disc separates cleanly from the screw — magnetic sorting recovers the galvanised steel, and the polymer collar goes through the polypropylene stream. The embodied carbon per fixing is small relative to the insulation and render layers above.