Burying posts Vs bracket's

[Brian18741]

Here's a quick render of the initial framing of a tree house I'm making for the kids. The posts are 5x5. The question is, do I bury them in concrete or bury U-bracket style post holders in the concrete?

To date, I've always buried the post but I have some U-brackets, just wondering will they be strong enough. Have the holes dug already, 300mm round, 600mm deep. The U-bracket has a 300mm "tail" of 19mm rebar.

The tree house deck is 4.5m x 2.4m. Total height above ground 3m. Also attached are bracket's in question.

 

[Bingy man]

Timber in the ground will eventually rot , those brackets I take it allows you to keep the timber above ground?? If that the case above ground is best , you can treat or paint them every year and because you can see them you will know if you have any issues with rot ( imo)

 

[Stigmorgan]

As Bingy says, the bracket will keep the post slightly above ground so greatly extends the life of the post, also as its not shown on your drawing can I suggest diagonal bracing in the corners to soldify/ brace the structure.

 

[rafezetter]

I also suggest you put a small thinnish non rot packer of some kind under the post, but smaller maybe half the size and centre it. I use offcuts of 9mm thick PVC fascia which this helps air get to the very bottom to dry it out, though I do also generally drill a few more screw holes in the bracket and then screw them in for support.

I do the same for tose bolt down metposts, a small packer between it and the concrete so it spends less time wet as it's no longer sitting on wet concrete for months of the year, as even though they are coated the coating often isn't great - so I also usually also spray them myself (inside and out) with zinc spray paint from a can, then a grey primer to blend a bit better with the concrete.

Yes I'm a little ocd in a good "belt and braces" sort of way.

 

[Doug B]

I prefer this type of arrangement as the bottom of the post isn't sitting on anything that will trap water & lead to rotting.

They are easy to get fabricated & designed for the job in hand.
sorry my photos a bit dark.