Three envelope systems, one set of flashings drawn for your building, and every penetration located before the sheet is cut. Water goes where the detail sends it — and where the detail is missing, it goes inside.
The frame decides how far you can span. The envelope decides whether you can work inside it in three years' time.
Profiled steel sheet, with daylight strips where you want them. The cheapest way to get a large dry volume, and the honest choice for a store that is not heated and never will be.
Sheet, core and sheet in one panel. Thickness follows the temperature you need to hold and the climate outside it; the joint and the fixing pattern follow the wind. Chosen together, not separately.
Thicker, cam-locked and vapour-tight, with the details that a food or pharma client will be audited on. The same panel also builds the partitions between two temperature zones.
Ridge, verge, eave, corner, plinth and every transition between two planes. Folded in our own workshop from the same coil and the same colour as the sheet, so a repaired roof matches the one that was delivered.
Gutters and downpipes sized from the roof area and the local rainfall, not from a standard length, and discharging where your site actually drains. On a long roof this is the difference between a wall that stays clean and one that does not.
Screws, washers, closures and sealant — the parts that fail first and are almost never drawn. Each one is called out at its position, so the crew is not choosing on the roof.
Almost every leak we are called about was designed in, months before anyone stood on the roof.
An undersized gutter does not overflow politely. It sends water back up under the sheet, and it finds the wall.
Cable tray, duct, pipe, flue. Each hole in a roof is a flashing, and a flashing needs to be made before the sheet is cut.
Steel sheet against blockwork, panel against concrete, two roofs at different heights. Different movement, different fixing, and a detail that has to be drawn on purpose.
Water that cannot leave stands. Ponding loads the frame, stains the ceiling and shortens the life of every fixing it touches.
Sheet moves with temperature. Fixings that hold it too tightly, in the wrong pattern, tear the sheet at the screw line in the second summer.
In a cold room, vapour moves from warm to cold. A barrier on the cold face traps the water inside the panel, where nothing can dry it.
A roof plan and the rainfall where you are building is enough to size the drainage. The rest follows from what the building has to do inside.
Send the roof plan
HONGJI SHUNDA