Loft Conversions Insulation – Sitework

Loft conversions insulation

Installation sequence

  1. Fix timber battens to the sides of the rafters to keep the insulation at least 50mm below the underlay.
  2. Cut Ballytherm Insulation boards to size and fit between rafters.
  3. Fix a second layer of Ballytherm Insulation boards across the underside of the rafters and secure with battens.
  4. Tape board joints with Ballytherm metalised tape.
  5. Fit the internal finish to the batten

Points to watch

  • Ensure all airspaces beneath the underlay are clear and vented.
  • Cut Ballytherm boards to fit neatly around penetrations. Seal with expanding foam.

Further Advice & Information

For more information about Ballytherm products, technical advice, or guidance on the suitability of our products for your project, contact us at + 353 (0)49 95 27000,, email us at or use our contact form.

Roof Insulation


Design Guidance