Modern marquees covers are made from Polyvinyl chloride (PVC coated fabric) – usually just referred to as PVC in the trade. It is very strong, tear resistant, waterproof and durable. Similar fabric is available in a variety of different qualities, thicknesses, strengths and properties.

When anything is manufactured – whether it is a car, a ship, a pair of trousers or a plate – it is made to a tolerance. i.e. it has to be within certain dimensional limits. Different products have different limits – a cup could be 10mm oversize and, whilst it would look different, it would still function. Parts of a nuclear reactor however are machined to 1000ths of a millimetre – an error here and the part won’t fit or the device will not work.

There is a common misconception that anything made from fabric has fairly wide tolerances. With clothing this may be the case but marquee covers have to fit an Aluminium frame. This frame will have been made to normal engineering standards – probably accurate to 1mm. As a result, the covers must be made to the same level of accuracy otherwise the completed structure will look ‘baggy’ and untidy or – worse – the covers won’t fit and it will not be possible to complete the marquee.

The most important property for marquee use – for safety reasons – is that it should be Fire Retardant. Other, cheaper, fabrics are available for applications where a Fire Retardant rating is not required, but, as it is a legal requirement for any structure in public use, it is not an option for marquee covers.

The strength of the fabric comes from the woven structure within the PVC. The PVC is supported by the weave and makes the cover waterproof.

The fabric should hold its colour – bright colours can fade whilst white fabric can yellow with age. Direct sunlight is the cause of this.

Because of the dual nature of its construction, PVC fabric can be welded or sewn to make a joint. 

Which method is used depends on the application and the practicalities of manufacture. Fittings are usually sewn into place and long joints are nearly always welded. If the joint needs to be waterproof then it has to be welded.
Special PVC fabric glue is also used in certain circumstances.

When sewing the thread used is heavy duty Polyester, not conventional sewing cotton. This thread is UV stable and rot proof. It will last as long as the covers.