Ground --) Wood iron beams (or anything iron) --) Stone ---) Wood

Each material has its limit of how high can you place it.
If you try to use a wood at already 8 red limit and put iron beam up, it will not work.


If you wana get even higher the limit, there is a trick you can use.

Clear the area where you want to build and make it as flat as possible.
Go into middle and raise the ground as high as possible you can.
From this ground cone you can now build out (i recomend putting up fireplace on top of this firecone for maximum buff area).

Use the big stone ones as a foundation and place them araund the cone.
Now build the tower in any shape you want.