Roller shutter insulation buying guide

Updated: 22 October 2026

The inspection lid is off a built-in roller shutter box, and the room-side board feels thin and cold. This roller shutter insulation buying guide is the choice of thickness, faces and fixing before you order. The roller shutter insulation comparison holds the price and star table for three Schellenberg packs on amazon.co.uk. Peter F. used those saved listings, Schellenberg's published notes, Approved Document L and Passipedia. There is no laboratory test of your box. A qualifying purchase can earn a commission at no extra cost to you. Measure the spare gap with the curtain fully raised, then match a pack to that gap and to the face that is actually cold.

Our top picks

Badge	Product	Thickness	Faces covered	Fixing	Note	Price	Offer
Best overall	Schellenberg Schellenberg 66267	3 mm	Long face, 2 rolls	Self-adhesive	8.6	about £17.28	View offer
	Schellenberg Schellenberg 66257	13 mm	Long face, 1 mat	Non-expanding foam	8.4	about £35.61	View offer
Best value	Schellenberg Schellenberg 66272	15 mm	Cheeks only, 2 panels	n/a on the listing	8.2	about £4.45	View offer

Best overall

Schellenberg Schellenberg 66267

8.6/10about £17.28

View offer

Rank 2

Schellenberg Schellenberg 66257

8.4/10about £35.61

View offer

Best value

Schellenberg Schellenberg 66272

8.2/10about £4.45

View offer

On this page

1.What you are lining
2.Three packs, three jobs
3.Thickness, WLG and area
4.What the listing must match
5.Rules that are not a badge on the pack

What you are lining

A built-in box sits above a window or a patio door. The thin inner board is the short path heat uses to leave the room. These packs line that pocket only where the inspection lid comes off without cutting the wall. A face-fixed box is a weaker case, because the cold air is already outside the heated room. With the curtain fully up the roll is fattest. If the void opens into a wall cavity, or the building is listed, a builder should treat the junction.

Three packs, three jobs

The saved shelf is three Schellenberg linings at £4.45, £17.28 and £35.61. Model 66272 (B006JJDVNY) is two Neopor cheeks, 300 by 360 by 15 mm, and they leave a cold lid cold. Schellenberg quotes WLG 031; the UK listing does not. Shapes are on the side panels versus insulation mat page. Model 66267 is two self-adhesive rolls, 1.50 m by 0.375 m and 3 mm. Isolate a 230 volt tubular motor before you work beside the cable. Model 66257 (B006JJ3E4A) is a 13 mm mat fixed with non-expanding foam. A few spare millimetres is the narrow roller shutter box case.

Testsieger

Schellenberg Schellenberg 66267

8.6/10about £17.28

View offer

Thickness, WLG and area

WLG is a conductivity group, not a thickness. The UK bullet on the 3 mm rolls says WLG 035. A French page for 66267 prints WLG 033. Do not blend them. As a rule of thumb, 3 mm near 0.033 to 0.035 W/(m·K) is about 0.09 m²K/W, and 13 mm at about WLG 035 is about 0.37 m²K/W. Passipedia illustrates a 40 mm phenolic lining. These packs are not that illustration. The mat stops at 1.00 m by 0.50 m. Where only a few millimetres remain, 13 mm is the wrong purchase.

What the listing must match

ASIN B01M12RO34 names both 66258 and 66267. In this set it is the self-adhesive roll, and the material cell says Fabric. Reviews on that line also describe rigid polystyrene. Match the bullet for 3 mm and two pieces of 1.50 m by 0.375 m. The board is B006JJ3E4A, model 66257. The cheeks are B006JJDVNY, model 66272. The Consumer Rights Act 2015 requires the goods to match the description. A 60% heat-loss bullet is the listing's claim, not a measured saving for your house.

Rules that are not a badge on the pack

Approved Document L for dwellings in England (2021, with 2023 amendments) asks for continuous insulation and limited thermal bridges, in paragraphs 4.14 to 4.19. On a new dwelling a junction can be calculated, taken from a library or SAP Table K1, or given a default y-value of 0.20 W/(m²K). That figure is not a score on a foam mat. Scotland, Wales and Northern Ireland use their own documents. These foams are not cavity barriers and they are not fireproof.

Common questions

Is 13 mm better than 3 mm if both say a similar WLG?

Thirteen millimetres wins on resistance only when the curtain still clears it. A similar WLG does not make a thin roll equal to a thicker board. As a rule of thumb, 13 mm at about WLG 035 is near 0.37 m²K/W, and 3 mm near 0.033 to 0.035 W/(m·K) is near 0.09 m²K/W. Buy the mat where that depth is free. With only a few millimetres spare, the 3 mm rolls still let the shutter move.

Do I need side panels as well as a mat?

You need the panels for the cheeks, not as a stand-in for the long face. Model 66272 is two Neopor boards of 300 by 360 by 15 mm, and they stop at the ends of the box. A cold lid stays cold if those boards are the only lining. A mat does not wrap the cheeks by itself, so many boxes want both. Some ends have so little depth that 15 mm is already too much.

Why does one title say 66258 and 66267?

The roll listing, ASIN B01M12RO34, prints both model numbers, and the material cell says Fabric. Model 66267 is the pair of 3 mm self-adhesive rolls, each 1.50 m by 0.375 m. Reviews on that line also describe rigid polystyrene, which is a different object. Match the bullet that states 3 mm and two rolls. If the parcel arrives as a board, or as a single roll, the description has not been met.

Will this satisfy Part L?

No pack in this set is a Part L certificate. Approved Document L in England asks you to keep insulation continuous and to limit thermal bridging, including on an existing home. A lining inside a built-in box can reduce one bridge. It does not supply a calculated junction, a library detail or the default y-value of 0.20 W/(m²K). Wales, Scotland and Northern Ireland have their own standards.

How many packs do I need for a window wider than 1 m?

The 13 mm mat, model 66257, is 1.00 m by 0.50 m, so one pack does not span a lid wider than a metre as a single piece. Order a second mat, or accept a joint, and keep the belt slot open. The 3 mm rolls are two pieces of 1.50 m by 0.375 m, so one pack can cover a wider lid. You may still want the cheek pack for the ends. Use the centimetre sizes on the listing.

How to insulate a roller shutter box

Best roller shutter box insulation in this set