Insulation Fixings

Insulation fixings are the mechanical half of an external wall insulation system. Working alongside the adhesive, they anchor the insulation boards into the wall behind and hold the system in place under wind load, its own weight and thermal movement. At Penguin BM we supply trade-quality EWI fixings, plugs and accessories in stock for fast UK delivery or collection from our Wembley store. Use the guide below to choose the right type and length, or speak to our team for bulk trade pricing.

What Are Insulation Fixings?

Insulation fixings, also called insulation board fixings, EWI fixings, mechanical fixings or ETICS fixings, are fasteners that pass through the insulation board, across the adhesive bed and into the structural substrate. They are used together with adhesive to fix boards made from EPS, mineral wool, XPS and similar materials to brick, block, concrete or timber. The adhesive does most of the bonding, but the mechanical fixing is what stops boards being pulled away in high winds or on taller buildings, so getting the specification right is essential to a long-lasting facade.

Insulation Fixings We Supply

• EPS fixing plugs with metal pin: our main board fixing, for anchoring EPS and insulation boards to solid brick, block and concrete. The metal pin is capped to limit thermal bridging and the plate sits flush for a render-ready surface.
• Insulation pressure plates (spreader washers): wide retaining discs that thread over the fixing to spread its load across a larger area. Commonly used with mineral wool and to add pull-out strength on exposed elevations.
• Spiral insulation anchors: lightweight fixings for attaching items such as downpipes, lights or fittings back onto a finished EWI system without breaking the render line.
• EPS disc caps for fixing pins: polystyrene caps that close the fixing recess, cut thermal bridging and stop shadowing showing through on dark renders.

What Length Fixing Do I Need?

The fixing has to reach through the board and the adhesive bed and anchor securely into the wall behind. As a rule of thumb, choose a fixing around 40mm longer than the insulation board, giving at least 25mm of anchorage into a sound substrate.

Board thickness	Typical fixing length
50mm	90 - 95mm
70mm	110 - 115mm
90mm	130 - 135mm
100mm	135 - 140mm
120mm	160mm
150mm	190mm
200mm	235 - 240mm

Mineral wool usually needs a fixing with a larger washer or spreader plate, so allow extra depth for the recessed head. If you are unsure about the substrate, a site pull-out test is the safest check. For thickness and system build-up help, see our EWI thickness guide.

How Many Fixings per m²?

As a working guide, allow around 6 to 8 fixings per square metre, using the higher figure on corners, around openings and on exposed or upper-storey elevations. Mineral wool systems generally need more fixings than EPS. Your system's ETA or manufacturer specification always takes priority over a rule of thumb.

Why Buy Insulation Fixings from Penguin BM

We supply the correct fixings for EPS, mineral wool and rigid board systems, matched to your substrate, all at trade prices with bulk discounts. Order online for fast UK delivery or collect from Wembley. Because fixings work as part of a system, pair them with the right insulation boards, fibreglass mesh and render finish.

What length fixing do I need for 100mm insulation?

Around 135 to 140mm, so the fixing clears the board and adhesive and anchors at least 25mm into a sound substrate. Add depth for mineral wool washers.

How many insulation fixings do I need per m²?

Typically 6 to 8 per square metre, more on corners, around openings and on exposed or higher elevations. Follow your system specification.

What fixings should I use for mineral wool?

Use fixings designed for mineral wool, usually with a larger washer or spreader plate to spread the load across the softer board, and expect to use more per square metre than with EPS.

Do metal pin fixings cause cold bridges?

Quality metal pin fixings use a plastic-coated pin and a capping disc over the head to limit thermal bridging, so they are widely used even on solid substrates.

Can I fix insulation with adhesive only?

Adhesive alone is rarely enough on its own. Mechanical fixings provide the restraint that keeps boards attached under wind load and over time, and most systems require them.