Commercial · Internal Wall Insulation (IWI)
Commercial internal wall insulation (IWI) in Suffolk
Upgrading the inside of external walls is a common part of refurbishment and conversion work. We install internal insulation to the specified build-up, insulation backed plasterboard, thin rolls where space is tight, or framed systems, and finish it ready for decoration, coordinating with your other trades on the details.
When it’s the right choice
- Residential conversions and refurbishments
- Rental property upgrades between tenancies
- Office and commercial refurbishments
- Buildings where external insulation isn’t an option
- Rooms and units where lost floor area matters
Build-ups we install
- Insulation backed plasterboard
- Bonded or mechanically fixed laminate boards, sealed at joints and junctions.
- Thin internal wall insulation (TIWI)
- Ultra-thin membrane or textile rolls, such as Permagard ISO-THERM, where room space or lettable area is limited.
- Framed systems
- Battens or metal framing with insulation and board, where walls are uneven or deeper insulation is specified.
- Acoustic upgrades
- Acoustic boards and insulation where the specification calls for it. Performance depends on the whole system.
What the work involves
- 1
Review the specification
We check the build-up, vapour control and junction details.
- 2
Coordinate
Electrical and plumbing positions, window reveals and services are agreed with other trades.
- 3
Install and finish
Boards are fixed, sealed and skimmed or taped ready for decoration.
Want a price for your internal wall insulation (iwi)?
Send drawings, a specification or quantities.
Things to know
- Moisture control
- Vapour control and ventilation must be specified correctly; we’ll raise anything unclear.
- Room sizes
- Insulation reduces internal dimensions, which can matter for lettable area or fixtures. Thin rolls cost far less room than boards.
- What affects the price
- Area and quantities, specification, access and working hours, programme and phasing, and how much of the work needs to be done around other trades.
- Thin insulation and insulated boards do different jobs
- A thin textile lining such as Permagard ISO-THERM uses much less room depth than insulation backed plasterboard, but it is not an equivalent thickness of conventional insulation. Compare the actual product and full wall build-up, rather than assuming the same thermal result. Damp causes and ventilation need assessing first.
Questions about internal wall insulation (iwi)
We install to the build-up specified by your designer. Design calculations sit with them.
Ask us about your projectYes. Boarding and finishing are done by the same team.
Ask us about your projectYes, ideal for phased refurbishment or occupied buildings.
Ask us about your projectWe do that too, see our commercial EWI page.
Ask us about your projectYes. Thin internal wall insulation (TIWI) uses ultra-thin membrane or textile rolls, such as Permagard ISO-THERM.
Ask us about your projectNot automatically. TIWI may suit a space-constrained wall, but thermal performance, moisture behaviour and compliance must be assessed for that particular build-up. Where a target performance is specified, the designer needs to confirm that the chosen system achieves it.
Ask us about your projectInsulation should not be used to conceal an unresolved moisture problem. Leaks, penetrating damp and ventilation issues need investigation. Adding an internal lining changes the wall's temperature and moisture behaviour, so junction and vapour-control details matter.
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Quote for commercial internal wall insulation (iwi)
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