I'm a retired failure analysis engineer for Victor Reinz and Mc Cord gaskets and have seen numerous failure modes.

Combustion issues like detonation and pre-ignition will damage the combustion armor (fire ring).

Overheats tend to crush the gasket and when the engine cools there will be a loss of clampload that creates fluid or gas migration.

Repair procedures include machining to a specified surface finish, some machinists believe incorrectly a rough finish gives "tooth" for the gasket to bite into! Sure fire failure!

Lack of cooling system maintenance with rust and scale build up prevent heat transfer of course.

Installing a head that is warped requires that clanpload is necessary to "straighten" the head instead of applying clanpload to compress the gasket.

Machining a Volvo head also requires that the cam bores remain in alignment. If a severely warped head is machined and no attention paid to the cam bores a fractured camshaft is likely.

Although this procedure is not recommended the perforated core gaskets will lose a small amount of clampload following several thermal cycles. I did a cold retorque on my 745T which now has 380,000 mi. on the rebuild.

It's also my opinion that full load should not applied in a bi-metal engine until head and block reach operating temperature. That should minimize "scrubbing" the gasket.

I'm also not a belever in idling to warm it up!