I’d love to find some sort of block or item that can be placed in a certain area to stop them from spawning there, if anybody knows any. Ive tried doors but they do spawn in between them, and we know half slabs and glass blocks definitely don’t work. Thanks
Any full block should stop them from spawning on the block under it, though if it is, itself, in the spawning zone golems could spawn on it.
Since the spawning zone is only 6 blocks high and the golems need a 4 block high area to spawn in, a floor of full blocks 3 blocks above the surface they are spawning on and another 3 blocks above that should do it.
Or you could remove the blocks they spawn on and up to 5 layers below them.
Actually, not quite _any_ full block!
There is a very interesting iron farm design using stacks of redstone blocks that allow golems to spawn on all 6 levels in the zone rather than just the maximum of 2 in a normal iron farm.
(I believe that works with top-slabs as well, though they aren't, of course, full blocks so they wouldn't be an exception to the "any full block rule".)
And if the surface the golems are spawning on isn't at the very bottom of the spawning zone then a single floor (or should that be roof?) 4 blocks above the surface (3 blocks between them) should be enough.