Calculate Zone Volume: zone is not fully enclosed


I created a HB zone with the surface by surface method because I have to assign different constructions to the surfaces. The output of the “createHBzones” component is a closed brep but when I run the simulation it gives me:

** Warning ** CalculateZoneVolume: 1 zone is not fully enclosed. For more details use: Output: Diagnostics, DisplayExtrawarnings;

How do I correct this warning?

Thanks for your help