Can fail - as shown by losing water and a white steam trail behind on start-up.
Whilst the best solution is to fit a new gasket, this requires considerable skilled work.
Certainly as a temporary repair, it has been found that "Steel Seal" from Halfords can save time and money in at least the short-term. It is expensive (£40) but beware cheaper versions which may not give the same result.
Haven't had a head off yet, but being overhead cam and with a cambelt etc to dismantle, it won't be a two-minute job.