Anyone had major drain repairs done, how long was guarantee?

[beanstalk]

We're buying a house that has had a major drain repair carried out. I've seen the paperwork - schedule of work, certificate of structural 'soundness' and the guarantee. The guarantee is only for 12 months though, which doesn't seem long. Anyone got similar experience?

[risingstar]

we had work carried out by our insurers, Direct Line, and this was guaranteed for 3 years.