If the roof is to be re-covered then the insulation can be installed on top of the joists making a 'warm deck' roof (check with manufacturers for details).
Os bwriedir ailorchuddio'r to, gellir gosod y deunydd inswleiddio ar ben y distiau gan greu to 'dec cynnes' (gofynnwch i'r gwneuthurwyr am fanylion).