When installing a knew fence insure the posts are at least 2 feet in the ground. Fill the hole with concrete to prevent the poles from shifting
Two feet? What about frost line, will the frost / ice force the post up from the ground come winter?
In climates where snow/freezing is present, any post that is to support a permanent device should be no less that 3 feet below the surface with an adequate drainage layer (ie 3/4 crush). Preferred is 4 feet +.
If you want your fence to last only 5 yrs or less before you need to repair them, put your post only 2 feet into the ground. If you want them to last 10 yrs plus, do it properly.
sorry guy's the last one is on the money good comments Lionel.
Frost in the ground is a ligitimate concern, however the effects are more significant when the structure is load-bearing, such as a foundation of a building, or a house, where heaving ( lifting and shifting of the foundation by ice) is possible. For fense posts, since they are not considered load-bearing, one may consider the 2 feet to be sufficent to balance the cost vs benefits, particularly in areas like Vancouver BC
My fence which had only been in for 6 years barely, had nearly all the concrete lifting out oft the ground. When I would mow the grass the wheels of the mower wound always come against the lifted concrete that held the fence post. I was told it was because the installer never went deep enough for the frost line.
good advice Dan
I would have to say from many years of installing fences and decks that a 3' deep post hole is pretty much minimum depth for a 6' high fence (Vancouver BC area).
The trick is to not use cement. Tamping the dirt back in the hole (if it's not too wet or sandy) is really the best way to go even if an outside source of good tamping gravel is needed to be brough in (road base works very well). Un-cemented posts do stand up very well to frozen ground and a treated post will simply last longer when not set in cement. Tamp Tamp Tamp and then some more tamping. If done properly the post should be as strong as any cemented post and it will outlast it by many years.
It's amazing how some of the local fence installers (usually subcontracting for larger companies) seem to be able to get away with 1'to2' deep post holes. Sure they will last for a few years, but you know it will only take maybe 4 to 6 years before the posts are very loose or excessively leaning from left to right as you look down the fence line. Lazy and cheap labour is all it is. I will fight to the death to get my holes dug to where I know is acceptable. There a very few situations, but I must admit that there are times when cement is needed as a last resort and I will use it when necessary.
Ok,,, now all you cement heads can flame away...
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