Weight: Your existing frames may not be able to cope with a clad over solution as it uses heavy timber, insulation materials and tiles. Something lightweight is needed and the lightest solid roof systems only weigh around 31KG/M².
Tip: Always ask your installer for the total unit weight of the new roof per Sq.M
Fire Safety: Due to not being effectively fire tested as a complete roof structure, a ‘clad-over’ system does not comply with present fire safety regulations, which they need to in order to satisfy the relevant section of building regulations. It’s likely that only certain components have been adequately fire tested. Solid roofs must be classified as AC, AB, or AA in accordance with BS476-3.
Tip: Only commit to the project once you have been given sight of the fire safety certificate for the entire roof.
Building Regulations: A further stumbling block with a clad over system is that it’s unlikely to receive Building Regulations Approval because of its poor thermal values and structural integrity. Planning permission is something entirely separate to this, so don’t confuse the two, with planning permission generally not needed. Your local Building Control will need to be informed of any modifications to a structure, such as when you are replacing a glass or polycarbonate roof with a roof, so that they can ratify the change of roof.
Tip: Don’t commence with the conversion before you have told local Building Control of your plans. At its conclusion, you should be given a Building Regulations ‘Final’ Certificate for safe keeping.