I have most of my hives (Langsroth) with pitch top covers. They are very easy to make.
I use 4" tongue and groove cladding for the body work = one layer all around( loose fit over hive) and second layer front and back only angled from topcentre down to end to form a low wide pyramid (glue the t/g join). An inner ring of 3/4" X 3/4" lumber (to sit on the hive) fixed so the level of the side piece tops are level with the lumber tops. for the roof I use either thin ply-wood or fluted plastic sheet cut 1-1/2" bigger all round, mark a centre line (centreing from side to side) and almost cut through with an angle grinder so as to fold the sheet over to suit the angle of the woodwork. Place on top ensuring equal overlap all round and glue/nail on. I also drill a 1" hole in the centre of the front apex and covering it withsome mesh stapled on the inside for ventalation. cool in the summer and space to add insulation in winter. It also is very pleasing to look at, much better than flat tops.