What should a quotation for a complete sandwich panel roof include?

Rooflights, chimneys and vents each reduce the area of panel at an opening, but each also needs support, cutting, edge finishing and sealing. A small roof with many penetrations can cost more per square metre than a large uninterrupted slope. Check the drawings for joints between panel ends and include the accessories these joints require.

Specify the core material, panel thickness, facings and coating to suit the required roof performance. Check support spacing, bearing widths, loads and the pitch permitted for the system. A minimum pitch quoted for one panel arrangement without rooflights or end laps applies only under the stated conditions.

If rooftop equipment or photovoltaic modules are planned for later, include their loads and fixings in the structural design. Check the capacity of any proposed attachment to the ribs of the outer facing. On an existing building, have the purlins and their connections assessed. The capacity of the existing frame still needs checking when the roof covering is replaced.

This example assumes an order for 240 m² of panels for a simple roof. All prices are illustrative and exclude VAT. Unit rates are rounded for display. The line totals use the unrounded rates.

The listed items total €13,313.00 excluding VAT, or about €55.47 per square metre of panels purchased. For an actual building, the quotation must also say whether gutters, penetrations and structural work are included. The example total covers only the items shown.

Removing an old roof requires a plan for waste and for protecting the building below. If the premises remain in use, agree the work sequence, how machinery will be protected and which areas will remain accessible. Taking off an entire slope in one operation may be impractical. The amount of roof that can be safely closed up at the end of each day may determine the pace more than the panel installation rate.

Before accepting a quotation, agree who will inspect the structure once it is exposed and how necessary repairs will be priced. List removal of old components and reinstatement of services separately. Identify materials that require special handling in advance. Record uncertainties about the existing building so that you can see which costs are still open.

Panel length affects the delivery vehicle, lifting method and space needed alongside the building. Check that the equipment can reach the most difficult part of the roof from an available set-up position. Hire costs depend on the time booked and when that position is accessible. A late delivery can leave hired equipment standing idle before installation begins.

Compare what each contractor allows for work at height, access platforms, panel lifting attachments and on-site handling. A labour-only rate per square metre leaves equipment to be priced separately. Agree how weather delays will be handled and charged. These details show whether the quoted price covers the way the job will actually be done.

Allow for inspections of drainage, fixings, coatings and service penetrations. Plan safe access while the layout can still be changed. A hard-to-reach gutter or a unit installed over a critical joint can increase the cost of every maintenance visit.

Assess energy savings from a thicker panel in the context of the whole building envelope and its heating system. Retain the insulation performance the building requires when comparing discounts. Each quotation should describe a complete roof that can be maintained, identify the documents to be handed over and the items to be checked at acceptance, and state what is priced separately.