Loft Insulation 100mm

Mineral Wool Loft Insulation Rolls & Slabs

Mineral wool is the most widely used loft insulation material in the UK. It's non-combustible, moisture-resistant and easy to cut and fit between joists.

Knauf Loft Roll and Superglass Multiroll are popular glass mineral wool options because they’re lightweight and affordable and offer ease of installation for DIY projects. Rockwool stone wool rolls and slabs offer higher density for projects where you need acoustic performance or fire resistance 

PIR & XPS Loft Insulation Boards

Choose loft insulation boards where space is limited or when insulating between rafters for a loft conversion. PIR boards (from brands including Recticel and Celotex) and XPS boards achieve significantly lower U-values at 100mm, making them the right choice when depth is restricted and thermal targets are demanding.

Sustainable Loft Insulation 100mm

Thermafleece and recycled polyester insulation rolls offer eco-friendly options without compromising on thermal performance. Sheep's wool naturally regulates moisture, absorbing and releasing humidity without losing its insulating properties, which matters more in older properties.

Choosing the Right 100mm Loft Insulation

For a standard loft floor, choose mineral wool rolls from Knauf, Superglass, or Rockwool for a practical and cost-effective option.

For a loft conversion or where space is tight, PIR or XPS rigid boards at 100mm deliver the thermal performance needed without taking up excessive depth.

For sound insulation, choose higher-density Rockwool slabs for acoustic and thermal insulation.

For older or period properties, Thermafleece sheep's wool (CosyWool)  is the natural choice, managing moisture without trapping it.

For sustainability, opt for Thermafleece SupaSoft for excellent thermal performance with a significantly lower environmental impact than conventional insulation.

Why Choose Insulation UK for 100mm Loft Insulation?

• Wide range of products — mineral wool rolls, PIR boards, XPS boards, and sheep's wool all available in 100mm

• Leading brands in stock — Rockwool, Knauf, Superglass, Thermafleece, Recticel, and more

• Competitive pricing — trade rates and bulk order savings available

• Fast UK delivery — next-day options available on most products

• All thicknesses available — from 25mm to 200mm if your project needs a different depth

• Sustainable options — eco-friendly Thermafleece sheep's wool and recycled polyester rolls

• Expert technical support — not sure what you need? Our team can help you choose the right product for your project

Not sure how much insulation you need or which product suits your job best? Our team are on hand to help. Contact us here or call us on 0300 303 45 78.