Kingspan TR26

You can buy Kingspan Thermaroof TR26 online from Insulation Wholesale. We stock TR26 in various sizes, from thinner 25mm boards up to thicker 150mm ones. We offer clear pricing on all TR26 boards, with nationwide UK delivery – order directly from our store.

TR26 pricing depends mainly on the insulation thickness you buy. Pack size and current market conditions also affect prices.

For boards measuring 2.4m × 1.2m, the approximate prices per pack are:

• Thinner boards (25mm–50mm): £200–£310 ex VAT.
• Mid-range boards (for example, 80–100mm): £200–£240 ex VAT.
• Thicker (around 120–150mm boards): £150–£190 ex VAT.

Yes. Kingspan Therma TR26 is designed specifically for flat roofs. This includes extensions and warm roof systems where the insulation sits on top of the deck and below a waterproof membrane.

Here’s why TR26 works for flat roof extensions:

• Its rigid PIR core gives strong thermal performance and resists moisture.
• It works with mechanically fixed single-ply waterproofing systems (the sheet membranes that are screwed or fastened down). Kingspan TR26 is mainly intended for mechanically fixed systems; alternative build-ups may require different insulation products.
• It is suitable for new roofs and replacing old flat roofs.

• Prepare the roof deck 

The roof deck (timber, metal, or concrete) should be solid, flat, clean, and dry. Fix any gaps and uneven areas before installing the insulation.

• Lay the first layer of TR26 insulation

Start at the lowest point of the roof. Place the TR26 boards with the long edges tightly butted together. Stagger the joints so vertical seams do not line up. This improves thermal continuity.

• Check insulation thickness choices

Plan your layout so that the total insulation thickness meets the required thermal performance. Use manufacturer guidance and building regulations for minimum thermal values.

• Fix boards in place

Fasten boards with suitable roof insulation fixings that go through the boards into the substrate below. The fixings should be spaced as per the roofing manufacturer’s instructions. Fixing type and spacing will vary depending on wind uplift requirements, deck type, and the waterproofing system used.

• Tape/seal joints

Seal joints with foil tape. This reduces air leakage and maintains steady performance.

• Install the waterproof membrane

Once the insulation is fixed, lay the chosen waterproofing membrane (single-ply) over the insulation. This is mechanically fastened to the top through the boards down to the deck. Follow the membrane manufacturer’s instructions carefully.

• Flashings and edge details

Fit edge trims, upstands, and flashings so water is directed away. Any change in the surface or penetration (like vents) needs sealing according to good roofing practice.