Design and drafting, approved before we roll

What the drawing office produces

For a pre-engineered building the set covers the frame design, column and rafter drawings, the anchor bolt plan with reactions for your civil contractor, bracing, purlin and girt layouts with punching details, sheeting layouts for roof and walls, and the flashing and gutter details. For a roofing-only job it is the sheeting layout, the cutting list and the flashing schedule.

Purlins are drawn to be rolled on our own lines, so every hole in the punching detail is one the machine can make, from 1.0 to 3.0 mm and up to 12 m. Sheets are drawn in lengths the trailer can carry, which is 12 m by road, with end laps of 200 mm (150 mm on roofs steeper than 15°) placed on purlin lines.

Approval before rolling

We send the drawings for your approval and wait. Your engineer, architect or PEB consultant checks them, marks them up, and we revise. Only a signed set goes to the plant. This costs a few days at the start and saves weeks at the end, because a sheet rolled to the wrong length cannot be stretched.

3D review on complex roofs

Where a roof has slope transitions, hips, or closures that have to match an odd angle, we model it and walk through the model with you before production. On the SMCC pharma unit the custom profiles and slope-matched closures were approved in the first review and the roof came through the monsoon without a leak. Read the SMCC job.

Full BIM models with clash detection against your services drawings are available on request.

What we need from you

• Plot dimensions and location, or an architect's plan if there is one.
• The clear height under the rafter, and the bay spacing if you have a preference.
• Crane capacity, span and hook height, and how often the crane will run.
• Mezzanine loads, and any large openings in the roof or walls.
• A soil report if you have one. If not, we design the anchor bolts on an assumed bearing value and say so on the drawing.
• For a roofing-only job, the purlin layout or a survey of the existing purlins.

We do not design the foundation itself. We give your civil engineer the reactions and the anchor bolt layout, and the footing design stays with them.

How the drawing office works with you

1. You send the briefPlot size, clear height, use of the building and any drawing you already have.
2. Preliminary design and budgetary quoteA frame layout and tonnage within three working days of reviewing your drawing.
3. Detailed drawingsFrame, anchor bolt, purlin, sheeting and flashing drawings, with a 3D review where the roof needs it.
4. Your approvalYour consultant checks and marks up. We revise until the set is signed.
5. Release to the plantThe signed drawings become the punching programme and the cutting list. As-built drawings come with the handover.