Guidance needed - fixing 3mtr posts

[Nagartath]

Hi, I need help. I need to install three 3mtr rounded posts in my garden.

I'm planning on using post-fix to secure them in the ground.

My question is....how much of the post needs to be secured?

The plan is to put a sail under tension between the posts, and possibly in time convert it into a pergola...my DIY skills aren't great so one smal step at a time


Any help from anyone is gratefully received

Thanks
Duncan

 

[Jackrae]

They shouldn't move if they are buried 1 metre but a lot depends on the strength of the ground soil.

 

[r896neo]

Good luck trying to dig a 1m deep posthole.

Dig it as deep as is possible but 600mm at the very least.

750mm would be good

Lastly don't use postcrete for a post like that use proper concrete.

 

[scbk]

As above, ideally about a spades depth, which is about 3ft.
2ft as a minimum but the deeper the better! Watch out for cables and pipes!

You don't need any concrete, they can be set in soil if you have a good tamper/punner


Might be worth adding a "foot" to the bottom of each post (scrap of wood) if they are going to have constant tension pulling on them

 

[freddiemercurystwin]

You don't need any concrete, they can be set in soil if you have a good tamper/punner

Might be worth adding a "foot" to the bottom of each post (scrap of wood) if they are going to have constant tension pulling on them

What?????????????

 

[Nagartath]

Thanks everyone, I'm a bit more confident now, I was thinking of digging down about 3ft and originally using post-fix. I'll now get proper concrete.

Thanks again everyone
Duncan

 

[ImayKnow]

As above, ideally about a spades depth, which is about 3ft.

Another 'What???????'

That is some spade !

 

[scbk]

That's roughly how long most spades are, if you can plonk a spade in a post hole and it disappears down to the top of the handle, you know it's a good depth

Nagartath, have you bought the posts yet? If not, go for slightly longer than 3m if you can, to allow for sag in the sail, and give plenty of headroom underneath

 

[Nagartath]

That's roughly how long most spades are, if you can plonk a spade in a post hole and it disappears down to the top of the handle, you know it's a good depth

Nagartath, have you bought the posts yet? If not, go for slightly longer than 3m if you can, to allow for sag in the sail, and give plenty of headroom underneath

Thanks scbk (I was hoping you were referring to the whole spade and not just the main bit )

I've got the posts, they are 3mtrs in length, its always a struggle getting anything in regards to clearance as I'm 6' 6"....its main function is to provide some shade for my baby daughter (nearly 2yrs) so as long as I can get in without garroting myself its good.

A followup query I have to the forum......how much concrete will I need for each post.

Based on burying the post approx 3ft what are the rest of the dimensions or is that not so important

I was thinking of 3ft deep x 1ft x 1ft?

Thanks again everyone

Duncan

 

[wrathkeg]

when planning my own project I found that many sources suggested a hole three times the width of the post (so, a 4" post = 12" hole); some suggested keeping the hole as narrow as possible.

 

[r896neo]

Make it as narrow as possible. Without using an auger you will struggle to keep it any narrower than 300 anyway.

Its best to try and keep the sides vertical i.e don't taper it and make it wider at the top.

 

[Steve]

I would want such posts to be a metre deep. If nesecary you can extend the posts on top, make a decorative feature out of the extension.

 

[Nagartath]

I would want such posts to be a metre deep. If nesecary you can extend the posts on top, make a decorative feature out of the extension.

How would I go about extending the posts? This sounds like a very good idea. I've seen things for square posts in B&Q but not for round ones.

Incidentally the posts are 75mm diameter approx.

Cheers
Duncan

 

[HERTS P&D]

Your posts are too thin!

Andy

 

[r896neo]

As above that post will snap under load before it comes loose of the concrete.

You could use a post foot similiar to this but a bit beefier

http://t1.gstatic.com/images?q=tbn:ANd9GcT2zQWUVHVOSm0Eix77oW8isF_-o1O3vauXL3DQnNkvxQFsaA7EWA

Alternatively having 2 posts with a solid bracing between them will make it much much stronger and mitigate the need for crazy depth holes.