Ten Questions to Ask Before You Sign a Tensile Structure Contract

A tensile structure quotation is easy to compare on price and hard to compare on substance. Two documents can carry a similar figure and describe quite different buildings. These are the questions we would ask if we were buying, in the order they tend to matter.

1. 01

   What exactly is in the scope?

   Design, engineering, fabrication, transport, installation and tensioning are separate activities. A quotation should say which of them it covers, and what it leaves to you.

2. 02

   Who prepares the drawings, and who approves them?

   Fabrication should not start until drawings are approved. Ask what you will receive: a layout, shop drawings, or structural calculations, and how long you have to comment.

3. 03

   Which membrane, exactly?

   "Tensile fabric" is not a specification. Ask for the coating family and the weight class, in writing. The difference between grades is the difference between a roof that ages gracefully and one that does not.

4. 04

   What steel, and what finish?

   Section sizes and wall thickness decide the frame, and the coating decides how it survives. Ask whether it is galvanised or painted, and to what standard.

5. 05

   Who does the foundations?

   Civil work is commonly excluded from a membrane quotation. If it is excluded, someone still has to do it, and the design of it depends on the uplift the roof generates.

6. 06

   What wind and loading basis was used?

   A roof is engineered for a site, not for a catalogue. Ask what design basis was assumed for your location and that it follows the relevant Indian Standard codes.

7. 07

   What are the payment milestones?

   Milestones should map to events you can verify: order, material delivery, erection, completion. Check they add up to 100% and that the last one lands after handover, not before.

8. 08

   What is the lead time, and what pauses it?

   A time in days means little without its starting point. Ours runs from approval of the final drawings. Ask what happens to the schedule if approval slips or the site is not ready.

9. 09

   What does the warranty actually cover?

   There are usually two: the installer's workmanship and the membrane manufacturer's own product warranty. They cover different things and run on different terms. Get both in writing.

10. 10

    What is excluded?

    The exclusions list is the most informative page in any quotation. Read it before the price.

Two answers that should make you slow down

The first is a quotation with no exclusions at all. Every real project has them, and a document without them has simply moved the argument to a later date.

The second is a specification that names no grades: no coating family, no weight class, no steel section. It is impossible to compare two such quotations, and equally impossible to hold anyone to one.

What a good quotation looks like

• A scope of work with an included and an excluded list, both specific.
• Named materials with their grades, not just "fabric" and "MS".
• Payment milestones tied to verifiable events, totalling 100%.
• A lead time with a stated starting point.
• Warranties separated: workmanship and manufacturer.
• A drawing and approval step before fabrication begins.

Common questions

Is the cheapest quotation usually the problem?

Not always, but a figure well below the others normally means something has been left out: a lighter membrane grade, thinner sections, or civil work quietly excluded. Compare the specifications first, then the numbers.

Should a quotation include drawings?

It should at least say which drawings you will get and when. Detailed shop drawings usually follow the order, but the quotation should commit to producing and getting approval for them.

How much detail is reasonable to ask for?

Enough to compare like with like: material grades, section sizes, finishes, scope boundaries and milestones. Any serious manufacturer can supply that without hesitation.

Our own quotations are built around these points, and the tensile structure guide explains the engineering behind them. If you have a competing quotation in hand and want a second opinion on the specification, send it across.