Whilst Colman’s may be famous for its mustard and other savoury products it certainly is not famous for leaking flat roofs. So when the roof over a main loading bay canopy started to cause dangerous wet conditions beneath, something had to be done. Colman’s turned to the Milne Partnership of Dereham, Norfolk for a solution to the problem.
A strip and re-roof was discounted as the loading bay would need to be closed whilst the work took place. The canopy abuts an administration block with windows overlooking the roof, also the flat roof had glazed areas providing essential natural light to the operatives beneath.
Nick Blackledge at Mine Partnership spoke with Paul Garrow at Advanced Cladding who suggested their ROframe flat to pitch structure in combination with a new trapezoidal sheet roof covering incorporating translucent rooflights over the existing rooflight locations. Hence the project could be carried out with little or no disturbance to the operatives beneath.
A design for the project was developed and Colman’s instructed Milne Partnership to proceed, so once the ROframe engineering calculations had been produced to confirm the proposals the project was undertaken. Advanced Cladding were able to provide their Site Engineer to assist the Milne Partnership team in erecting the ROframe structure before fitting the new roof covering and rooflights.
After removing the loose chippings and debris the new ROframe base members were laid over cold applied mastic and fixed through the roof into the supporting structure beneath. The base members were laid at 1500 c/c’s and perpendicular to the direction of the existing structure to evenly spread the new roof loads.
The first tilt frames to be built were at the abutment to the higher level administration block and attached to the block. Continuous cleats were fixed over the first two frames for additional strength and support against potential snow drifting.
This photo shows the attachment of the first tilt frame to the abutting building.
Here the two adjacent tilt frames at the gable end of the canopy are built at the standard 1500 spacings with diagonal bracing fitted to prevent side sway and with continuous cleats as at the other end of the roof.
Once the remaining tilt frames and supporting props have also been built on a grid of 1500 the standard 500 long cleats are fitted over the tilt frames and over the prop locations, thus transferring the new roof loads directly to the existing roof structure beneath.
Here we see the completed ROframe structure with frame bracing, cleats and purlins all in place. Note the 120 deep zed rafters used to span over the existing rooflights which were the only element on the structure not built from the standard ROframe profiled section.