30mm Insulation TB4000

30mm insulation is a thin layer of thermal material used where space is limited, but some heat control is still needed. It is not designed to provide full thermal performance on its own. Instead, it helps improve comfort, reduce cold spots, or boost an existing build-up without changing layouts.

What is 30mm thick insulation?

30mm insulation thickness means the material measures 30 millimetres from face to face. That depth limits the heat resistance it can provide, but it also makes it easy to fit where thicker products cannot.

At 30mm thickness, performance depends heavily on the material:

• Rigid foams trap heat using closed air cells
• Mineral fibres slow heat movement by holding still air
• Vacuum-based panels, such as VIPs, reduce heat transfer by removing air altogether

A 30mm thick insulation layer will usually support another insulating system. It works best when combined with thicker insulation elsewhere in the structure.

What is thick 30mm insulation used for?

30mm insulation thickness is used where space or detail matters more than raw performance.

Its typical applications include:

• Reducing cold bridging around window reveals and door liners
• Adding a thermal break behind battens or linings
• Upgrading floors or walls where levels cannot be raised
• Improving comfort in refurbishments without major strip-out

It is often chosen during retrofit work, shop fits, and tight refurbishment jobs where losing even 10–20mm of space can cause issues.

Types of 30mm insulation

30mm insulation is usually available in these materials:

PIR (Polyisocyanurate)

Rigid foam panels with high thermal resistance per millimetre. PIR works well where space is limited, and a firm surface is needed. Foil facings also help control heat movement by radiation.

Phenolic foam

Similar in form to PIR but usually slightly better at slowing heat flow. Phenolic boards require careful handling due to their brittleness.

EPS (Expanded Polystyrene)

EPS offers modest thermal resistance at 30mm, but it handles moisture well. It is light and easy to cut.

XPS (Extruded Polystyrene)

Denser than EPS and better suited to damp-prone or load-bearing areas. XPS is commonly used under floors and in areas that require high compression resistance.

Glass mineral wool

Made from fine glass fibres. At this depth, it offers limited thermal benefit but good acoustic absorption. It compresses easily, so it must be installed carefully to prevent gaps.

Rock mineral wool

Heavier and denser than glass wool. It performs better acoustically and handles fire exposure well. Thermal gains are modest at 30mm, but it is useful where fire or sound control is needed.

VIP (Vacuum Insulated Panels)

A specialist product with extremely high performance for its thickness. VIP panels outperform most conventional insulation materials, but must not be cut or pierced. They are used only where design demands ultra-thin insulation.

Other materials

Aerogel blankets and specialist composites are also available in thin formats, but availability is limited, and costs are high. These are usually specified by designers.

A thick 30mm insulation layer only delivers strong results when the material matches the job.