If the wall is also load-bearing, by virtue of supporting a roof or a storey above, it will also need to have fire resistance regardless of its distance from a boundary.
Os bydd y wal hefyd yn cario llwyth, gan ei bod yn cynnal to neu lawr uwch ei phen, bydd angen iddi allu gwrthsefyll tân ni waeth beth fo'r pellter rhyngddi a ffin.