I've got one of these to do in a department store restaurant in a couple of weeks, 25m long x 12m wide, went to survey it on Thursday, the store managers opening comment was "Mind it's a shrinker!". However, the seams are fine but there is signs of shrinkage at one end, pulled away by 1" or more, obviously from a previous clean. As a precaution I've taken some digi photos of the damage and quantified it in the quote, which takes account of the extra work required.
I've done a few of these type before but not one of this length, in the past I have always secured both ends with ring nails every 3" - 4", I may even secure this in the middle too. Need to be careful when cleaning over the seams.
They also want all their wicker dining chairs (140) washed down and cushions cleaned, table legs washed and wicker dividing screens washed!! All night job, two machines and 4 people