The Complete UK Home Insulation Guide 2026: From Loft to Floor

By Alumix Insulation Global | Loft insulation, roof insulation, multifoil insulation, underfloor insulation, wall insulation

 

With energy bills still far above pre-2021 levels and the UK government’s Great British Insulation Scheme and ECO4 programme pushing homeowners to act, there has never been a better time to properly insulate your home. According to the Energy Saving Trust, a poorly insulated detached house can lose up to 25% of its heat through the roof, 35% through walls, and 15% through the floor.

 

At Alumix Insulation Global, we manufacture a complete range of reflective foil insulation and multifoil insulation products for every part of your home — loft, roof, walls, floor, garage, conservatory, and beyond. Whether you’re a DIY homeowner tackling a weekend project or a professional installer working on a full renovation, this guide will help you choose the right product for every job.

 

Why Choose Reflective Foil Insulation?

Traditional insulation materials like mineral wool and fibreglass work by trapping air. Reflective foil insulation works differently — it reflects up to 98% of radiant heat rather than absorbing it. This makes it:

 

• Significantly thinner — ideal where space is limited (lofts, stud walls, under floors)
• Lighter and easier to handle — one person can install it without specialist equipment
• Moisture resistant — unlike fibreglass, it won’t absorb water or harbour mould
• Dual purpose — keeps heat in during winter and reflects solar heat out in summer

 

Foil insulation is particularly effective in the UK climate, where homes need to perform across cold, damp winters and increasingly warm summers.

 

1. Loft Insulation

Loft insulation is the single most impactful upgrade a UK homeowner can make. The loft is where the most heat escapes, and it’s also the easiest area to access and insulate yourself.

EXTRA 16MM and EXTRA 16MM GOLD

Our EXTRA series is the go-to solution for insulating a loft or attic space. At 16mm thick, it combines multiple reflective aluminium layers with a high-performance polyethylene foam core. The GOLD version uses ultra-low emissivity films for even greater thermal resistance — ideal for lofts in older properties with limited depth between joists.

 

• ✅ Ideal for: loft insulation, insulating between rafters, sloped ceilings
• ✅ Takes up a fraction of the space of mineral wool rolls
• ✅ No itching, no specialist PPE required during installation

MEGA 40MM and TRIPLEX 25MM (Super Cool Series)

For maximum performance in larger loft spaces or exposed roof structures, the Super Cool series delivers our highest thermal ratings. The MEGA 40MM is our thickest product, engineered for cold lofts, industrial roofs, and agricultural buildings. The TRIPLEX 25MM features three reflective layers for outstanding year-round performance.

 

• ✅ Ideal for: cold loft insulation, flat roof insulation, warehouse and barn roofs
• ✅ Reduces summer heat gain by up to 95%
• ✅ Excellent choice for properties with large uninsulated roof spans

 

2. Roof Insulation and Underroof Membranes

Whether you’re re-roofing, building an extension, or upgrading an existing structure, roof insulation installed directly under tiles or metal sheets makes an immediate difference to comfort and energy use.

SILVER 6MM FR and SILVER 8MM FR

Our best-selling products for under-roof insulation. Available in 6mm and 8mm, these double-sided aluminium foil rolls are installed between or beneath rafters, under corrugated metal roofing, or as a breather membrane layer. The FR (Fire Retardant) rating meets UK building regulations for internal use.

 

• ✅ Ideal for: pitched roof insulation, metal roof insulation, tile underlay
• ✅ Available in NET versions with a reinforced woven outer face for improved tear resistance
• ✅ Lightweight and quick to install across large roof areas

BRONZE 4MM FR and BRONZE 4MM FR NET

Our most affordable foil insulation roll — perfect for budget-conscious projects, secondary applications, or non-residential structures. The NET version holds up exceptionally well in exposed environments.

 

• ✅ Ideal for: shed insulation, garage roof insulation, outbuildings, polytunnels
• ✅ Best value per square metre in the Alumix range
• ✅ Easy to cut with standard scissors or a utility knife

 

3. Multifoil Insulation for Walls

Multifoil insulation has become one of the most searched-for insulation types in the UK, particularly for solid wall properties where traditional cavity wall insulation is not possible.

MULTI+ 10MM and MULTI+ 10MM GOLD

Our MULTI+ series is a true multilayer reflective insulation — multiple aluminium foil films bonded with polyethylene foam spacers, all in a 10mm roll. It performs far above its slim profile, making it the perfect solution for internal wall insulation where every centimetre of room space matters. The GOLD version uses premium low-emissivity foil on both faces for superior performance.

 

• ✅ Ideal for: internal wall insulation (IWI), solid wall insulation, stud wall lining
• ✅ Also effective as external wall insulation (EWI) under render or cladding
• ✅ Compatible with timber and metal stud framing systems
• ✅ Helps meet Part L building regulations for thermal performance

 

4. Underfloor Insulation

Underfloor insulation is one of the most underrated upgrades in UK homes — particularly in older properties with suspended timber floors or cold concrete ground floors. It improves warmth underfoot and reduces draughts significantly.

BLH-B, BLH-B BIG HD, and BLH-F (Floor Series)

Our dedicated floor insulation range is designed for installation beneath laminate, engineered wood, tiles, or directly onto concrete slabs. The BLH-B Big HD is our heavy-duty version, engineered for high-traffic commercial and residential floors. The BLH-F is optimised specifically for floating floor systems.

 

• ✅ Ideal for: underfloor insulation, under laminate insulation, insulating a cold floor
• ✅ Acts as both a thermal barrier and a vapour control layer
• ✅ Ultra-slim profile — won’t raise floor height noticeably

Poly Foam 10MM

A pure polyethylene foam roll without foil faces — ideal as a basic thermal and acoustic underlay beneath floating floors in lower-demand applications.

 

• ✅ Ideal for: acoustic underlay, basic floor thermal insulation
• ✅ Budget-friendly for large floor areas

 

5. Radiant Barriers

Radiant barriers are pure reflective products — no foam core — designed to be installed with an adjacent air gap where they reflect radiant heat rather than conduct it. They are widely used in loft spaces, metal buildings, and agricultural structures.

RADIANT BARRIER Smooth and RADIANT BARRIER Woven

Both versions reflect up to 98% of radiant heat. The Smooth finish offers maximum reflectivity, while the Woven version provides superior mechanical strength for demanding installations.

 

• ✅ Ideal for: cold loft radiant barrier, metal building insulation, barn insulation, livestock housing
• ✅ Install by stapling or draping beneath roof joists or rafters — no adhesive needed
• ✅ Woven version resists tearing during installation over large spans

 

6. Conservatory Roof Insulation

One of the fastest-growing search terms in the UK — conservatory roof insulation is in high demand as homeowners seek to use their conservatories year-round without excessive heating or cooling costs.

SILVER 8MM FR and EXTRA 16MM

Both products work excellently under polycarbonate or glass conservatory roof panels, dramatically reducing heat loss in winter and cutting solar overheating in summer. Their slim profiles mean they can be fitted without significantly reducing internal height.

 

• ✅ Reduces conservatory heating bills substantially
• ✅ Easy DIY installation — no tradespeople required
• ✅ Can be cut to fit any roof panel shape

 

7. DIY Insulation Kits

Not every job needs a professional. Our DIY insulation range is designed for homeowners who want to take on insulation projects themselves — with products that are easy to handle, cut, and fix without specialist tools or training.

DIY BASIC, DIY SUPERIOR, and DIY PLATINUM

Three tiers to match your project and budget:

 

• DIY BASIC — entry-level foil insulation for garages, sheds, vans, and small spaces. All you need is a utility knife and aluminium tape.

 

• DIY SUPERIOR — multilayer performance for lofts, walls, and under-roof projects in residential properties.

 

• DIY PLATINUM — our highest-performing DIY product, equivalent to professional-grade multifoil insulation for demanding applications.

 

• ✅ Ideal for: garage insulation DIY, shed insulation, campervan insulation, loft DIY

 

• ✅ No specialist tools needed

 

• ✅ Available for international delivery

 

8. Specialist Applications

Van and Campervan Insulation

Campervan insulation and van conversion insulation is one of the most active niches in the UK insulation market. Our BRONZE 4MM FR and DIY series are widely used to line van walls, ceilings, and floors — lightweight, flexible, and effective at reducing both heat and condensation.

Greenhouse and Polytunnel Insulation

Greenhouse insulation during UK winters can extend growing seasons significantly. Our BRONZE FR NET and RADIANT BARRIER WOVEN products are used in polytunnels and glasshouses to retain overnight warmth while remaining durable against moisture and condensation.

Agricultural and Livestock Buildings

The RADIANT BARRIER WOVEN and MEGA 40MM are widely used in farm building insulation — reducing heat stress in livestock during summer and retaining warmth in winter, without the hygiene risks of fibrous insulation materials.

 

Quick Reference: Which Product for Which Job?

Application	Recommended Product	Thickness
Loft / attic insulation	EXTRA 16MM / EXTRA 16MM GOLD	16mm
Cold loft / flat roof	MEGA 40MM / TRIPLEX 25MM	25–40mm
Under-tile / roof insulation	SILVER 6MM FR / SILVER 8MM FR	6–8mm
Shed / garage roof	BRONZE 4MM FR / BRONZE FR NET	4mm
Internal wall insulation	MULTI+ 10MM / MULTI+ GOLD	10mm
Underfloor / under laminate	BLH-B / BLH-F / Poly Foam	5–10mm
Conservatory roof	SILVER 8MM FR / EXTRA 16MM	8–16mm
Loft radiant barrier	RADIANT BARRIER Smooth / Woven	<5mm
Campervan / van conversion	BRONZE 4MM FR / DIY series	4mm
DIY home projects	DIY BASIC / SUPERIOR / PLATINUM	variable

 

Does Alumix Foil Insulation Meet UK Building Regulations?

Yes. Our FR (Fire Retardant) range is designed to meet the requirements of Part L (Conservation of Fuel and Power) and Part B (Fire Safety) of the UK Building Regulations. For projects requiring compliance documentation, please contact us directly and we can provide relevant technical data sheets and test certifications.

 

Can I Claim Government Grants for Foil Insulation?

The Great British Insulation Scheme (GBIS) and ECO4 programme provide funding for insulation upgrades for eligible households. Reflective insulation products can qualify when installed by a registered TrustMark or MCS-certified installer. We recommend checking your eligibility at gov.uk and requesting a quote from a certified installer who can source Alumix products.

 

Conclusion: One Range, Every Application

From a quick campervan conversion to a full whole-house renovation, Alumix Insulation Global has the right foil insulation product for every job. With over 33 years of manufacturing experience, certification to international standards, and supply to more than 20 countries, we are the trusted partner for installers, builders, and homeowners across the UK and beyond.

 

👉 Get a free quote or browse the full product range at alumixinsulationglobal.com.

 

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