Is it required to resurface the head cylinder after taking it apart?

It can be measured with a flat edge to make sure it hasn't warped beyond service limits. The machinist can do that.

Planing the head does make it perfectly flat, but also will cause some compression ratio increase. That can be corrected with thicker head gaskets if necessary, but a head so warped as to require such deep resurfacing is probably cracked as well, but not always.

If your head is warped and you put it back together, the gasket may fail or you could crack the head. Do what you want, but make sure you're right.

Honda Civic Cylinder Head

No, a simple wipe of any debris and the head cab be fitted to the block.

You must use a new head gasket.

Make sure that no "gasket goo" is used with the head gasket.

Did you find a damaged head gasket once the head was removed?

It at least needs to be checked for flatness. The usual cause of head gasket failure is overheating, which makes the aluminum cylinder head expand twice as much as the iron block. That forces the head to bow upward and if it bows too much it will be permanently warped. (Remember your mother: "If you make faces like that it will freeze that way someday!") It is quick and inexpensive for an automotive machine shop to check the flatness - some don't even charge - and not very expensive to get it milled if it needs it.

If the cylinder block and head are both flat and level there is no need to resurface. If the car overheated excessively it's possible.

Aluminum heads can warp if overheated (yours is aluminum)

It is recommended to get the head checked before re installing as it would suck to reassemble the engine and find out the warped head has just blown your new head gasket.

If you are just changing the gasket, and using the same head, it's better NOT to resurface the head. My question to you is: why are you changing the gasket?

not all heads need skimming. odds are that if its an all aluminium head? it will warp on removal and need a light skim.

we can have head checked for flatness before deciding. unless we are good at checking for flatness? eg level. blue light ? any engineering shop can do so for you. anything over 5 thou. tends to start being in world of skimming but depending on head design.luck and skill of person bolting back bigger warping can be sealed.

I have for example replaced head ( cast iron) on many cars without any skimming .