I'm doing a roof where one face has a hip up to a lower ridge, then another hip up to the upper ridge. Distance from lowest batten to lower ridge is 1800 and distance from that ridge to upper ridge is 2480.. I figure I could put 6 rows on the entire face at 300 centres, then increase the batten spacing to 310 for another 8 rows to get to the top.. Is this done? or do roofers normally just space to the longest length (eg do the whole roof at 329 which is the best fit for a 4280 distnace for a tile that's 345 max spacing) and then cut the row of tiles that doesnt land exactly on the lower ridge?