/ sinking a pole
Im installing a wooden pole, which will stick up 5m above the ground (its going to have a 10kg bat box on the top). How much needs to be buried? Or am I better bolting it to a slab? Anyone got any ideas?
I'd guess it depends entirely on what the ground is like. Into granite, a well drilled 50cm hole might be fine. Into a peat bog, considerably deeper would seem to be wise.
Itll be earth I reckon. We'll not be drilling into granite thats nuts. Youd just bolt straight to it ;-)
I have it in mind there is a rule, quarter bured 3/4 not? Or a third, two thirds?
Dig as small a diameter hole as you can. Getting the loose soil consolidated after is difficult and if not done properly could make the pole move slightly in the hole you've dug.
You will find that most lamp posts are less than 1m deep, but often set in a tube in concrete so the bearing area is larger at shallow depths. The wind load on a single pole Is much less than say a fence post which has a huge area to catch the wind and a relatively small area of soil to resist over-turning.
A quick google suggests the yanks use 10% total pole length plus 2 feet for power distribution poles. These carry line tension too do that should be conservative.
Does it have to be on a pole?
Why not fix it to a wall?
As a general rule, bat roosts need stable temperatures for both roosts and hibernation. So out of the sun fixed to an external wall is normally best - Unless, yours is very well insulated..?
Hahaha I can imagine it! Thank all for the input its really appreciated. Oh, and the reason for poles is cos there are no walls or trees, the bats will be fully laden (hopefully pregnant females), the bat box design is specced accordingly.
You're right, ideally you do need to tamp as you go...
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