Nothing finer than spending an afternoon relaxing in a hammock!
I own several hammocks, a Hennessy Asym Delux Explorer, DD Camping hammock and a custom clone of a Warbonnet as they weren't until recently available in the UK and I'm tempted to get the real thing soon anyway.
It'd be nice to use the garden as a space to use them on warm summer nights or to dry them after a wet weekend camping. The temporary solutions are fine, but I don't really have a place to store them and if I have to do any significant assembly, it'll probably never get used.
So I built a permanent solution using 4x4 and postcrete!
Step 1: Tools & Materials
1x9" Post borer/Auger - Manual is fine (see pic below)
1x Drain spade (like this)
Drill with bits
Mitre Saw (preferably one capable of doing 4x4 posts...) but manual will do if you can cut straight.
Spanner or bit that fits your drill for the coach bolts
3x3m 4x4 treated posts
6x90mm M8 coach screws
6xM8 Large washers
2x90mm M10 Eye bolts
2xM10 Large Washers
6 bags of postcrete
Step 2: Hole Digging
Rough guides are 1/3 the length of the post - so in this case about 3ft or 1m Since my auger only goes 3ft, 3ft it was.
Tips for drilling:
Only do 3-4" at a time, less if the ground is hard. Each go, slop down some water. We didn't need to as the ground was saturated, so it went down like butter.
If an area is too root infested, go elsewhere. I have a strapped wrist at the moment from slicing through 4" roots with the drain spade.
You only need to put in the main posts to start with, do the supports after.
How far apart? My hammocks need about 16ft between posts. You ideally need the ridge to be taut and level, but the lines to the hammock to slope at approximately 30'. I experimented by having someone hold a post, looping my hammock over the first post and having a good guess.
Step 3: Fixing the Posts
To use postcrete, simply fill your hole 1/3 with water, insert your post. Pour the postcrete around the post. I like to use a bit of 2x4 or 2x1 to mix it a little, but I've been told it's not necessary. My packet told me a 9" hole with 4"x4" post would only need one packet of postcrete. I was a bit overzealous and added about 2 - 2.5 If you stop adding 2-4" before the top of the hole, you can put grass around it and it'll look nice. If you do what I did, you'll have a nice artistic lump of concrete round the base of your post.
Make sure you've got the right angle (90' up) and the posts are facing each other. Mine are a little off, but it doesn't matter. It's more noticeable once you add the supports.
I've been told the end of the post should be sticking in the mud and not in the postcrete which allows the post to drain rather than fill with water. Since I'm in a heavy clay area with a low water table, it didn't make much odds to me.
Step 4: Adding Supports
Lean them against your post so the 45' angle is against the post.
Dig some holes with the drain spade around where the end is - I use a drain spade because it makes really neat deep holes & only dug about 1ft down.
Fill hole with 1/3 water, add post, add postcrete. I used 1 bag.
Pre drill some holes in your support post to take the coach screws.
Step 5: Adding a Hang Point
You can also see a little damage where I was using a similar technique with the amsteel.
By putting in an eye hook you can use hammocks with Whoopie slings and main lines such as the Hennessy. With Whoopie slings, karabiners give you the ability to snap on and off, where as Hennesseys can be lashed direct to the loop using their recommended knot. The damage to the wood is from a Whoopie sling which was looped over the post. Not a good idea.
Drill a 10mm hole, thread through the eye bolt and use the washer and nut. You can see on the below I've used a 2nd washer - this was to spread the weight in the wood as much as possible. The large washer is called a repair washer.
If you've not already angled the top posts, grab a ladder and cut the post so that the water pours off the top and preferably away from your hammock.