A flat roof builtproperly, to last

PVC gives you fewer joints, less weight, UV resistance and a weld that can be checked along its full length — which is why it dominates on halls, estates and modern housing. Torch-on bitumen remains a sound choice when refurbishing existing bituminous coverings and where the client wants to stay with a familiar system. We install both — the decision comes after looking at the substrate, not from a price list.

The key is levelling the corrugated surface. We fill the lower flute with rigid insulation, PIR or XPS wedges, up to the top edge of the trapezoid, then add a second layer of insulation or OSB on top to get a flat substrate. The levelled area has to extend at least one trapezoid beyond the penetration on every side and run all the way to the ridge. PVC-coated metal flashing goes onto the outer trapezoids with sealant underneath, and the membrane is mechanically fastened and welded straight to that flashing. Only then do we detail the chimney itself.

Not if the bases are non-penetrating. We fit feet that never pierce the waterproofing — the load is carried by ballast and a properly sized contact area, and the membrane stays continuous. The bigger risk with PV is not the installation itself but servicing the panels later on a roof with no anchor points, which is why the two jobs are best done together.

Water can enter a dozen metres from where it drips inside. Instead of opening up the covering blind, we use the electrical method, which pinpoints damage to the membrane to within centimetres, or smoke testing, where the smoke escapes exactly at the failed weld. Only once the source is located do we plan the repair — which keeps the intervention local.

Yes. By default we build with our own proven materials, because then we stand behind both the product and the workmanship. If the client already has a materials contract or their own arrangement with a manufacturer, we install what is supplied — with the difference that our guarantee then covers our workmanship and the welds, not the product itself.