An 82.5mm insulation board is a rigid panel used in buildings to reduce heat transfer through the building fabric. This rigid panel is suitable for fitting into walls or roofs with ease.
What is 82.5mm thick insulation board?
An 82.5mm thick insulation board has a fixed overall depth of 82.5mm. This thickness is commonly supplied as an insulated plasterboard, combining insulation with a plasterboard lining. It contains a rigid PIR (polyisocyanurate) or phenolic foam insulation core that limits heat transfer. The closed-cell foam structure restricts heat transfer through the building.
PIR and phenolic general offer higher thermal resistance per millimetre than mineral wool or polystyrene, based on typical declared λ-values. Mannok, Unilin, and Kingspan 82.5mm insulation boards are common examples of insulating panels with very low thermal conductivity relative to their thickness.
What is 82.5mm thick insulation board used for?
An insulation 82.5mm thick board is used in:
Internal wall insulation to improve thermal comfort without significant loss of internal space.
Pitched roof insulation where permitted by the roof design and specification
Drylining – With plasterboard bonded on, it becomes part of the finished surface, cutting installation time.
82.5mm boards are often specified where thinner insulation cannot meet performance targets within available space.
Types of insulation 82.5mm board
Insulation Wholesale stocks these common 82.5mm rigid insulation boards:
PIR Insulation Boards – Short for polyisocyanurate foam. 82.5mm PIR insulation boards provide strong thermal resistance relative to their thickness. They are light to handle, can be cut accurately using appropriate insulation cutting tools, and work well with dot-and-dab adhesive or mechanical fixings.
Phenolic Insulation Boards – These use phenolic foam instead of PIR. At the same 82.5mm depth, they provide slightly higher thermal resistance than PIR boards because phenolic foam has even smaller closed cells, resulting in a lower declared thermal conductivity. They also have good fire performance.
Insulation 82.5mm thickness board benefits
An insulation 82.5mm thickness board gives you:
Better thermal resistance for its size – PIR/phenolic foam is efficient and reliable at this depth.
Dual-purpose panels – Boards insulate and provide skim-ready plasterboard in one step.
Easier on site – Rigid boards do not sag like some loose materials and cut neatly (with the right tools).
Reduced cold bridging – Continuous boards with properly detailed joints help limit heat loss at studs and joists.
Drylining ready –Factory-bonded plasterboard removes the need for a separate lining layer in many applications.
Why choose our 82.5mm insulation boards?
Here’s why DIYers and trade customers choose 82.5mm insulation boards from Insulation Wholesale:
At Insulation Wholesale, we supply 82.5mm insulated plasterboard from leading brands.
We offer reliable products backed by strong supplier relationships, plus guidance on the thickness and type that suit your project.
We make it easy for trade teams, self-builders, and site managers to get the materials, thanks to trade discounts, pallet deals, and an experienced technical team who can help you quote larger orders.
All supported by competitive pricing and fast nationwide delivery from UK stock.
At Insulation Wholesale, you can purchase 82.5mm Insulation Board at low wholesale prices with fast delivery for most of items within 2-5 days. Competitive rates guaranteed.
FAQ
Where to buy an 82.5mm insulation board?
You can buy an 82.5mm insulation board online from Insulation Wholesale. We stock multiple 82.5mm insulated panels suitable for walls, roofs, and framing, with flexible purchase options such as trade discounts and pallet deals. We supply from UK-held stock and can organise fast nationwide delivery to your site.
How to cut 82.5mm insulation board?
To cut 82.5mm insulation thickness boards:
Wear your PPE – goggles, gloves, and a dust mask.
Mark the cut line, using a straight edge as a guide.
Use a sharp, fine-toothed handsaw or an insulation knife for neat cuts.
For boards with foil facings, score the foil first, then cut the foam core.
How to install 82.5mm insulation board?
Prepare surface – Make sure walls or rafters are dry and smooth.
Dab adhesive – If using adhesive, dot and dab the back with board adhesive.
Level up – Push the board into place so it is flush with adjacent boards.
Dry fix – Use appropriate mechanical fixings if dry-fixing the boards.
Seal joints – Tape edges to minimise draughts.
Finish – You can tape, joint, and plaster the visible face if the board is bonded to plasterboard (optional).
Follow the manufacturer's installation details as well as site-specific requirements, since these may be slightly different for different foam cores.
Mannok Therm Laminate-Kraft / MLK PIR 70mm + 12.5mm PIR Insulated plasterboard is a high performance, fibre-free insulated board. Mannok Therm Laminate-Kraft / MLK PIR has a kraft paper facing on one side and plasterboard bonded to the other side.
82.5mm Unilin Safe-R SR/TB is a high-performance insulation that offers excellent thermal efficiency. Its design ensures quick and secure installation, delivering long-term energy savings and safety compliance.
82.5mm Unilin Safe-R SR/TB-MF Mech Fix Insulated Plasterboard is designed for mechanical fixing, it offers excellent thermal efficiency, easy installation and ready-to-finish surface for walls and ceilings.
