In one instance, mats were adopted for 24 months. In another similar case, DFR staff had to threaten legal action if the mats were not returned. This, however, was not the norm as most bridge mats subject to callback were returned within three to six months. When questioned on preferred bridge mat length, interviewed DFR staff responded that 20-foot mats had met their customers' needs. Bridge mat longevity ranged from 24-48 months with an average life of about three years.
Water absorption can also lead to deterioration of non-treated wood and in some cases, failure.
The latter was experienced in D-1, nearly causing a skidder to topple from the remaining two bridge mats. The DMs purchased for this project were subject to callback for inspection in 1999 to ensure the mats were structurally sound. Interviewees indicated a fair level of success was attained in loan participants' subsequent actions of purchasing their own bridge mats. Approximately 30 loggers either purchased or made their own bridge mats after participating in the DFR Loan Program. The number of bridge mat sets generated in this matter was estimated to be between 40-45 sets.