As carpets age they sometimes will need a re-stretch. Constant foot traffic flexes the carpets construction. Historic flooding situations such as a bathroom or kitchen overflow or leaking plumbing can affect the carpets adhesives which may not correct 100% when dried. When carpets are first installed, they need to be stretched when installed, this is sometimes not done correctly especially in difficult areas. Although this may not be evident for several years, the carpet may later show signs that it is no longer taught.
Carpets which are stretched tight flex around a lot less; this results in less friction and reduces wear. Carpets which show ripples or excess movement will have a shorter life and will eventually be damaged beyond repair. Commercial carpets are usually glued down for this reason, since the carpet cannot move around, it will endure foot and trolley friction much longer. Call EcoSan to take a look at your carpets if you need a nip and tuck.