Superglass insulation review: loft rolls from Stirling

Quick answer: Superglass makes glass mineral wool in Stirling and has been owned by the Belgian group Etex since June 2023. Multi-Roll 44 is 0.044 W/mK, Euroclass A1 and up to 84% recycled glass. At 100mm it’s £32.75 ex VAT for 12.12m², about £2.70 per square metre, checked 27 July 2026.

Who owns Superglass now

Superglass Insulation Ltd has made glass mineral wool at its Stirling plant for decades. Etex closed the acquisition on 22 June 2023 and dropped Superglass into an insulation division that already included Ursa. Etex called it a top three player in the UK and Ireland glass mineral wool market, with 200 people at the Stirling plant.

For a homeowner the ownership matters only in one respect: the plant is still running and the product is still British-made, which isn’t true of every roll on a merchant’s rack. We haven’t tested it. This is a read of published data, certification and merchant prices, checked 27 July 2026.

Multi-Roll 44 specification

• Declared thermal conductivity 0.044 W/mK
• Euroclass A1 to BS EN 13501-1:2018, deemed non-combustible
• Made from up to 84% recycled waste glass, per Superglass
• Part-perforated so a 1200mm roll splits without cutting the full length
• CE marked, UKCA marked, EUCEB certified
• CCPI assessment mark, certificate 005800129/0227

The CCPI mark is worth a sentence on its own. The Code for Construction Products Information was set up after Grenfell to verify that what a manufacturer publishes about a product is accurate, clear and up to date. Not many insulation products carry one, though Rockwool’s Twin Roll does. It says nothing about how well the wool insulates and quite a lot about whether you can trust the number on the label.

What it costs against Knauf

Knauf Loft Roll 44 at 100mm works out at £2.32 per square metre on the same day at Trade Insulations. So Superglass is about 16% dearer for an identical declared conductivity and an identical fire class. That gap moves week to week and merchant to merchant. Buy whichever is cheaper on the day, because there’s no performance argument between them.

The last column is the one to use when comparing. Price per square metre per 100mm of depth strips out the thickness and shows the material rate. Superglass runs almost flat across the range. A 200mm roll buys you no bulk discount. It’s just more wool.

Where it fits in a house

Cold loft at ceiling level. That’s what Multi-Roll 44 is designed for, and it does it well. Lay the first layer between the joists. Then run a second across them at right angles, to break the thermal bridge through the timber. Our loft insulation thickness guide covers the current target and why the cross layer earns most of the saving.

It’ll also do stud partitions and rafter-level work in a ventilated roof, though for a partition where sound is the point, a denser stone wool slab is the better tool. And it’s the wrong material anywhere depth is fixed: at 0.044 W/mK you need roughly double the thickness of a PIR board. See mineral wool, PIR and EPS compared for the side by side.

What to check on delivery

Glass wool arrives compressed into polythene at roughly a quarter of its finished volume, which catches people out twice. First on storage: a pallet that looks manageable in the drive turns into a loft full of wool once it’s opened. Second on performance, because the rolls need time and space to recover their full thickness. Cut the wrapping, let them expand, then lay them.

The other thing to check is that the perforations line up with your joists. Multi-Roll 44 is supplied at 1200mm and part-perforated so it separates into narrower widths without a knife. If your joists sit at 400mm centres you want the three-way split; at 600mm you want the two-way. Getting this wrong means cutting every roll lengthways in a hot loft, which is a miserable afternoon and produces far more waste.

The honest verdict

Superglass is a commodity product, and that’s a compliment. Glass wool at 0.044 W/mK is a mature, tightly specified material, and the mainstream loft rolls all declare the same number. There’s no premium here to pay for and no quality gap to worry about.

Two reasons to actively choose it. Superglass puts the recycled waste glass content at up to 84%, which matters if you’re chasing an environmental specification. And the CCPI mark gives you a verified data sheet, which after the last decade in UK construction isn’t nothing. Otherwise price on the day decides it.

One thing that won’t decide it is a Trustpilot score. We looked. There’s no meaningful consumer rating for any insulation manufacturer, because they all sell through merchants, and the scores you do find belong to distributors. On 27 July 2026 the sums came out at £2.32 for Knauf against £2.70 for Superglass, so Knauf was the buy that day. Next week it may not be. For a modelled cost of the whole job rather than roll prices, use the cost calculator or the insulation product guide.

FAQs

Is Superglass as good as Knauf?

On the numbers that matter, yes. Both declare 0.044 W/mK for their standard loft roll and both are Euroclass A1. Superglass was about 16% dearer per square metre at 100mm on 27 July 2026. That gap flips between merchants, so buy on price.

Where is Superglass insulation made?

Stirling, Scotland. The plant has operated for decades and carried on under Etex ownership after the June 2023 acquisition, with 200 people on site.

Is Superglass loft roll fire safe?

Multi-Roll 44 is Euroclass A1 to BS EN 13501-1:2018, which is the highest reaction to fire classification and means it makes no contribution to a fire. See insulation fire safety for what that means alongside downlighters and cabling in a loft.