Bonded roofing connects roof layers through adhesion using a suitable system. The term alone does not specify the product or application process used.
What does this mean on your roof?
The substrate and existing materials influence whether a proposed bonded arrangement is suitable. Moisture, contamination or unidentified layers may require investigation.
A new outer membrane with favourable product properties does not establish adequate adhesion to an old layer whose condition has not been assessed or recorded.
Ask which layer will receive the bond, what preparation is included and how edges and penetrations are treated. Distinguish the connection between layers from waterproof seam detailing. Where several products meet, their compatibility needs to be established. Keep the system description in your roof records rather than recording only the broad label bonded roof, which leaves important construction choices unexplained.
Frequently asked questions
Does bonding always use the same adhesive?
No. Application depends on the system and products.
Can any old covering remain in place?
No. Suitability, condition and moisture need assessment before retention is agreed.
Consulted 19 September 2026. Check requirements for your own address and selected system.