There really is no maximum size as most of the systems are designed to bolt to one another to have as wide as required. There is a maximum projection however.
Most of the automatic electric retractable roof systems we install can bolt together and use intermediate rain guttering systems when required feeding the water into the front channel. The maximum projection would be due to a combination of the size of the fabric roll and of course the fact that any terrace cover or canopy needs a pitch for the rainwater to drain properly and you cannot simply keep going down and outwards otherwise you would hit the floor.
You can however install 2 units back to back and create a gable shape like a normal roof and deal with the rainwater as required depending on the proximity to a building, although many of the systems will stand alone if required away from a building.
Take the Pergola 210 or the Weinor Plaza systems for example, both are fabric roof systems that retract fully and use an aluminium framework system to provide the basis for the system and enable the fabric to run in the side channels and increase fabric tension for higher wind and rain ratings.
The largest projection for most of the domestic systems is 6 metres but the widths can go up to 7 metres in one cover or ‘field’ as it is called but then you simply bolt systems together to make the width as long as required and can also bolt 2 systems back to back to form a gable shape with the 2 no. 6 metre projections making a 12 metre cover but with limitless widths.
The commercial systems we offer for restaurants, cafes, pubs and other types of business where outdoor areas are used as well as the indoors can of course be designed as larger bespoke systems with unusual shapes and limitless sizes, again with a limit however on the projection just like a normal roof would have, especially as a 10 degree pitch is recommended to aim for to ensure the rainwater runs off without damage.
For normal retractable self supporting awnings the maximum width for a couple of models we offer is 14 metres with a 4 metre projection. A large covered area of fabric by any standards!!
Below the image shows 2 Markilux 8800 retractable fabric roof systems on a steel frame system and these can be couple infinitely.
Below is another example of using a framework system and then adding the retractable fabric roof system to cover large areas for commercial use adding extra space and covers for your pub or restaurant