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Internal Wall Insulation Non combustible Thermal
Internal wall insulation is installed on the inner surface of uninsulated or solid exterior walls. This insulation is suitable for solid or uninsulated exterior walls and is typically available in boards, slabs, or rolls.
What is indoor wall insulation?
Indoor wall insulation refers to any insulation system installed on the interior side of exterior walls. This type of insulation is often useful for properties where the external wall cannot be insulated.
Installing insulation on the internal wall establishes a thermal barrier between the indoor space and the wall. This barrier reduces heat transmission through the wall and keeps the interior warmer.
What is internal wall insulation used for?
It is commonly used in terraced houses, listed buildings, and properties with decorative facades. External insulation is often unsuitable for these properties, making internal insulation the preferred option. It is also ideal for enhancing insulation in older properties.
Insulating interior walls helps to:
- Improve thermal efficiency.
- Reduce heating costs.
- Eliminate cold spots and draughts.
- Enhance indoor comfort during cold months.
- Reduce surface condensation on cold walls
- Meet Building Regulations for energy performance in renovations.
Types of internal insulation for walls
The best choice for insulation for interior walls depends on available space, budget, and wall type. Here’s a quick look at popular options and what makes each ideal for different needs:
PIR insulation
PIR boards are ideal for limited space, as they deliver remarkable thermal performance in a slim profile. They are easy to cut and install and can be used on both solid and stud walls. PIR boards with foil facings improve vapour control.
Insulated plasterboard
These are PIR boards faced with plasterboard. They offer a two-in-one solution that delivers efficient thermal protection and a smooth wall finish. A practical option for quick installation, they are ready for decoration immediately after fitting.
Ensure all board joints are sealed to prevent cold spots and air leakage.
Mineral wool insulation Rolls or Slabs
Flexible rolls and slabs can expand to seal spaces, making them excellent for uneven surfaces. However, they may require a vapour control layer to prevent internal condensation.
They are easy to cut and install, and are easily added to timber and metal stud walls. Rolls and slabs also offer good acoustic insulation and fire resistance.
Party wall insulation
Party wall insulation is used in walls that separate two properties – like semi-detached or terraced homes. While it is primarily installed for acoustic control, it also offers limited thermal advantages.
Sound-absorbing insulation, usually mineral wool, is used to fill the wall cavity or internal lining. The fibrous material traps sound vibrations and stops them from passing through the wall, while also minimising heat loss between homes.
Partition wall insulation
Partition wall insulation is mainly used for sound control rather than heat retention. It is installed in internal partition walls, such as between bedrooms or offices, where it sits between the studs.
The insulation absorbs voices, television noise, and general airborne sounds. Breaking up sound waves in this manner makes rooms quieter and far more comfortable.
Benefits of internal wall insulation
Installing indoor insulation on walls comes with benefits such as:
- Enhanced comfort due to better heat retention
- Higher energy efficiency
- Lower heating bills
- Acoustic insulation, as it dampens sounds from outside and between rooms
- Flexible installation, as you can decide where to add the insulation without making exterior changes
- Improved property value because energy-efficient houses have higher EPC ratings and market appeal.
Why choose our wall insulation for indoor use?
Here is why Insulation Wholesale is the go-to store for indoor wall insulation:
- We offer a wide range of PIR insulation, EPS insulation, and mineral wool options.
- Our interior wall insulation delivers excellent U-value improvement with minimal thickness.
- It is simple to install, with lasting results.
- All our indoor insulation is compliant with UK Building Regulations.
- Get expert advice and support from our insulation specialists.
- We aim to deliver within 1–3 working days unless stated otherwise.
Save energy, cut heating costs, and insulate your property the smart way. Shop internal wall insulation today for fast delivery across the UK.
At Insulation Wholesale, you can purchase Internal Wall Insulation at low wholesale prices with fast delivery for most of items within 2-5 days. Competitive rates guaranteed.
FAQ
What is internal wall insulation?
Internal wall insulation is the material used to add a thermal layer to solid-walled homes. It is especially useful for older solid wall houses and is commonly available as PIR boards, EPS panels, and mineral wool.
How much does internal wall insulation cost?
The total cost depends on material choice and project size. Prices are usually calculated per square metre for both boards and rolls. They can start as low as £2-£3 and climb to £49 or more per m².
These prices typically refer to supply only; installation costs are additional.
How thick should internal wall insulation be?
Thickness varies depending on the material and available space. Thicker insulation provides better thermal resistance, but consider whether you have enough space for it.
For optimal performance, a thickness range of 50 - 100mm applies to PIR boards. EPS boards require 75 - 100mm, while mineral wool slabs and rolls require 100 - 150mm.
Consider getting a recommendation for optimal insulation thickness from a qualified installer. Thicker insulation improves U-values by reducing heat loss through the wall.
How to fit internal wall insulation?
You can fit insulation on interior walls using two methods. In both, the walls should be clean and dry before adding the insulant.
- Direct Fix: This is where you attach the boards directly to the wall and add a finish of your liking.
- Batten and Frame: Here, you fix timber or metal studs to the wall, insert the insulation slab or roll, then cover with plasterboard.
Improper installation can lead to interstitial condensation; always use a vapour control layer where required.
If unsure of doing a perfect installation, consult a qualified installer to avoid condensation or cold bridging issues.
Internal Wall Insulation Range
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100mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 4.32m2 Pack
100mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
£42.91£51.49 Ex VATInc VAT£9.93£11.92 Per m2 Add to cart -
100mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 2.88m2 Pack
100mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
£23.41£28.09 Ex VATInc VAT£8.13£9.76 Per m2 Add to cart -
140mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 2.88m2 Pack
140mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
£39.18£47.02 Ex VATInc VAT£13.60£16.32 Per m2 Add to cart -
50mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 6.48m2 Pack
50mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
£27.94£33.53 Ex VATInc VAT£4.31£5.17 Per m2 Add to cart -
75mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 4.32m2 Pack
75mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
£27.24£32.69 Ex VATInc VAT£6.31£7.57 Per m2 Add to cart -
100mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 3.6m2 Pack
100mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
140mm Knauf Rocksilk Flexible Insulation Slab 1200mm x 600mm 2.16m2 Pack
140mm Knauf Insulation Rocksilk Flexible Slab is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications as well as the fire protection of a loft conversion floor. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
180mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 25.92m2 Pallet
180mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
POA Get a quote -
25mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 14.4m2 Pack
25mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
25mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 138.24m2 Pallet
25mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.
POA Get a quote -
25mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet
25mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
POA Get a quote -
30mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet
30mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
POA Get a quote -
40mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet
40mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
POA Get a quote -
50mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 7.2m2 Pack
50mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
50mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 8.64m2 Pack
50mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
POA Get a quote -
60mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 103.68m2 Pallet
60mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
POA Get a quote -
60mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 92.16m2 Pallet
60mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
POA Get a quote -
70mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 92.16m2 Pallet
70mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
POA Get a quote -
75mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 4.32m2 Pack
75mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
90mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 86.40m2 Pallet
90mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
POA Get a quote
