The world's largest supplier of underfloor heating

John Guest - Overlay Boards - Joists

John Guest - Overlay Boards - Joists

In stock

RRP: £43.38Our Price£25.00 inc. VAT
Next working day delivery
Order within

Panel Calculator


Low profile system for new build or renovation projects. Grooved foil faced insulation panel for installation 15mm tubing over existing floor structures to facilitate the use of Underfloor Heating within timber flooring structures.

Underfit is designed for use with timber suspended or floating floors. 15mm JG Layflat pipe is installed into a grooved foil-faced panel with 200mm centres over existing floor structures, either between battens or under the floor between existing joists.

  • Grooved foil-faced panel
  • Easy to install
  • Medium to low heat output & response
  • Low profile
Heat outputapprox 50-60w/m2
Recommended flow temperature50-60ºC
Maximum circuit length100m
Typical cover per loop15-20m2
Individual panel size350X1200X50(mm)

Delivery options

Our delivery costs vary according to order size and location. For more information see our Delivery page.

As standard we include FREE 2 - 3 working day delivery to all UK mainland addresses (excluding, Channel Islands & Eire) on all heating products.

All orders placed after 3pm on a Friday and at the weekend will be processed on Monday and placed on next working day delivery

Please note: orders must be placed before 3pm to be eligible for our Next Working Day, Next Working Day Before 10:30am and Saturday delivery options.