Tuesday, July 27, 2010

Building a Garden Bench

This simple design allows you to place an attractive garden bench on any spot you choose, even one with some slope to it.  We used to build this type of bench in a natural sloping hollow or bowl shaped terrain to create a natural outdoor chapel or amphitheater when I worked at camp.  These aren't hard to build and are very sturdy and durable, especially if you use pressure treated lumber.

What You Need for a 10 foot long bench:

Three 3-foot long 4 x 4 posts
Post hole digger
Six bags of concrete
One 10 foot long 2x10 or 2x12 depending on the width of........well, let's not go there.
One 12 foot long 2x8's
Three 3 foot long 4x4's
Circular saw
Drill and 7/16 inch bit
Spirit level
Fifteen 5 inch long galvanized half inch lag screws with washers
Six bags concrete mix

Selecting the Site
Choose a site where the tops of the posts will sit level. You can build one on a slope if you run it parallel to the slope.  You need ten feet of linear space for a ten foot bench. You can make a six foot bench with two posts if you want to go shorter.

Digging the Holes
Dig three 2 foot deep post holes 4 feet apart. Dig them wider at the bottom than at the top so the concrete will sit more firmly in the ground.

Setting the Posts
Place each of the 3 foot long 4x4's in a hole.  Turn the bench board on edge and set it on top of the posts. Set the spirit level on top of the board.  Adjust the depth of each post till the bench is level by digging the hole deeper or throwing more dirt in the hole.  Once all three posts touch the bottom of the bench edge and the bubble in the spirit level is centered, mix up the concrete and pour it into the hole. Don't make the concrete too wet. Dryer concrete is stronger concrete. Allow to cure overnight before banging on the posts or attaching things.

Mounting Brackets
Cut the 2x8 board into two foot lengths.  Cut the boards to the shape shown in the drawing. Drill two holes in the center of each board as shown.  Hole the brackets up against the posts as shown and predrill into the post.  Do this for each bracket.







Attach the Brackets
Screw the lag screws and washers into the mounting brackets and posts. The brackets will be on opposite sides of each post running lengthwise to the bench. Tighten the screws till the wood dimples slightly under the washers.







Positioning the Bench 
Lay the bench plank on top of the posts and brackets. Position the plank so it overhangs the outside posts evenly (about a foot).  Drill three pilot holes through the plank into the top of the posts.  Screw the lag screws and washers through the top of the plank and into the ends of the posts.




Finishing the Bench
If you used pressure treated wood, you don't need to do anything else. If not, you should stain and varnish or paint the bench to protect it from the weather and insects.

This bench can be placed almost anywhere. You can even carry the parts, precut and drilled, back into the woods and bolt yourself a bench along your favorite hiking trail. You don't have to concrete around the posts, just tamp the dirt around it with a shovel handle. It will hold well enough for a seldom-used rest stop. 

You can also replace the 2x10 or 2x12 planks with a pair of 2x6's. Just leave a half inch gap between them and screw them to the brackets with galvanized screws. Don't put them closer together than a half inch or the flexing of the boards can pinch your behind between the planks.

If you cut a 45 degree cut on each corner, it will give the bench a more finished look.

You can also string a series of planks on posts four feet apart to make pew-like seats. Two boards can share a post, just screw them into the post and brackets with galvanized screws.  If you angle the ends, you can even bend the rows of seats to follow the curve of the terrain.

It's not hard at all and these benches look really nice when you're done with them.

Tom

5 comments:

  1. Hi good day ! nice post you have . It's very nice , I have plan to setting up my garden can you give me an idea or steps on how to make it beautiful. i have heard some garden accessories such as garden spinner , wind chimes , wind spinners and many more . I want to try this things in my garden but i don't know how to get the right accessories . I hope you can help me . thank you .

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  2. I do have a post on how to build tuned wind chimes. They are a lovely addition to your garden, especially if you tune the chimes to a line from a favorite song. Adds a personal touch to your garden. I have one set that plays a line from the Harry Potter theme. If the wind gusts just right, it plays variants of the theme.

    Have fun with your garden. Check the archive or follow my weblog for notification when I post new stuff. I do add some backyard garden stuff once in a while. If you have an interest in waterfalls, I can give you a link to one I did on how to do fake rockwork.

    Tom

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  3. Is that 2 bags of concrete per hole? Also, do you use a drill for the lag screws? Thanks for this, using it for my Eagle Scout Project!!!

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  4. You can probably get by with one per hole for the project since the bench won't get the kind of stresses that a swing or volleyball post would get on it, but I always get tow per hole. That way I'm sure I have enough to fill the hole and tamp it down tight. If there's an extra you can store them or take them back. How much you use depends a lot on how stiff the soil is (use more in sand) and how big you make the hole. If you use more concrete, your bench will remain solid for much longer.

    Alway predrill lag bolts. You can screw them in, but the wood will split since the lag screws act as wedges. You could split the bench down the middle especially given the weight on the edges of the bench.


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  5. I have used lag screws to hold down the bench to the post and recessed them slightly so the heads are level with the surface of the bench. You'd want to cover the holes or fill them in with some kind of water resistant filler, otherwise the recess will collect water when it rains. The galvanized screws should work fine, but I would check them once in a while and replace them if they corrode.

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