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How to Build a Custom Tree Bench
Learn how to build a detached hexagonal bench around a tree.
The backyard is a favorite area for a California family, so they plan to construct a hexagonal redwood bench there to add to their enjoyment. A very large evergreen tree stands in the ideal spot. Encircling the tree with the bench will save space but require careful positioning so that the bench legs do not injure the tree's roots. The do-it-yourselfers will construct the hexagonal bench in two primary pieces, each forming two of the six sides and supported by three pairs of legs at each joint. After they position these modules around the tree, they will add the remaining two sides to complete the hexagon.
Step by Step Instructions with Video
Step
1
Draw a Plan and Assemble Your Tools and Materials
Plan the project on paper to determine the design and dimensions and then assemble your tools and materials. You will be using a power miter saw and power drill/driver, so don't forget safety equipment such as protective eyewear. The project requires cutting multiple leg pieces of identical dimension as well as sets of outside, middle, and inside seat planks, etc. Make a cut list and set up a cutting jig to facilitate and expedite the work and ensure that you cut all the required pieces of a given size before adjusting measurements for the next set of cuts.
Step
2
Set Up Your Miter Saw and Work Surfaces
Set up a worktable and miter saw and saw horses for the redwood lumber.
Step
3
Adjust the Saw for a 30-Degree Miter with a Vertical Cut
Start by adjusting the miter saw for a 30-degree miter, but leave the blade perfectly vertical. (If it is not a compound miter saw, the blade is stationary in the vertical position.)
Step
4
Set a Stop and Clamp the Redwood in Place
Set a stop for the required length of the inside seat plank and then clamp a length of redwood on the bed of the saw.
Step
5
Miter Six Inside Seat Planks
Miter 6 planks (only) to length for the set of inside planks for the bench seat. In our plan, there are three planks of three different lengths in each seat section that forms one of the hexagonal sides. The 6 middle planks are longer than the 6 inside planks, and the 6 outside planks are longer than the middle planks--but all three sets of planks must have both ends mitered to 30-degree angles. You will cut/miter the other sets of planks in a later step.
Step
6
Position the Planks Around the Tree to Confirm Their Fit
Position the six inside seat planks around the base of the tree temporarily to confirm that they will join properly in a hexagon and leave enough room clearance for the tree. The bench will be free-standing, rather than attached to the tree in any way, but we must leave room for the tree to grow. The tree can serve as a back rest for adults who sit on the bench.
Step
7
Lay Out a Mitered Plank Parallel with Two Uncut Planks
Lay out one of the mitered inside planks on the worktable along with two un-mitered planks. Position them parallel to one another and separated by 1/4-inch thick spacers.
Step
8
Align a Straightedge and Trace the 30-Degree Angled Miter
Align a straightedge along the 30-degree angle on one end of the inside plank and trace the angle on other two seat planks that represent the middle and outside. Repeat this process on the other ends so that you have marked both ends of the middle and outside planks with a 30-degree cut line. Mark the sets of seat planks for the other sections of the hexagon in the same manner.
Step
9
Miter the Remaining Seat Planks on the Traced Cut Line
Cut all the sets of seat planks on the 30-degree cut lines.
Step
10
Arrange All the Seat Planks Face Down in a Hexagon
Arrange all the seat planks face down on the patio or driveway, wherever there is a flat surface big enough to accommodate them. You may want to spread a drop cloth first to protect the redwood from dirt and abrasions. Put 1/4-inch spacers between the inside, middle, and outside rows and arrange them in a hexagon with their mitered ends firmly butted against the other planks in the set. Leave the seat planks in this position.
Step
11
Cut Six pairs of Identical Bench Legs
Cut six pairs of identical legs from two-by-sixes using straight cuts. In our project, we made them about 18-inch long. If you want your bench higher or lower, then adjust the length of the legs accordingly.
Step
12
Cut Six Pairs of Indentical Braces
Cut six identical pairs of one-by-fours about 18-inches long to serve as cross braces for the tops of the legs.
Step
13
Align a Pair of Legs and a Brace
Align a pair of legs and position a one-by-four brace flush with the top ends.
Step
14
Secure the Braces Temporarily with a Nail Gun
Secure the brace temporarily with a nail gun, driving in two diagonally positioned nails through the brace and into each leg. Flip the assembly over, and secure another brace on the other side--at the same end. Repeat this process to assemble and brace the other five pairs of legs.
Step
15
Clamp a Leg Assembly to the Worktable and Align the Power Drill
Clamp a leg assembly to your work surface and position a combination square upright against your power drill to ensure that you are holding it at 90-degrees to the surface of the leg assembly.
Step
16
Pre-drill Clearance Holes for Carriage Bolts
Pre-drill two clearance holes in each leg for carriage bolts. Position them diagonally for maximum support.
Step
17
Drop in a Glavanized Carriage Bolt
Drop a galvanized carriage bolt into the first hole.
Step
18
Tap the Bolts with a Hammer to Set Them in the Wood
Tap it with a hammer to drive the rectilinear shank/collar into the wood while leaving the round head protruding. Set the remaining 3 carriage bolts in the leg assembly.
Step
19
Add Washers and Nuts
Add washers and nuts to the other ends of the bolts after flipping the assembly over.
Step
20
Tighten the Nuts with a Socket Wrench
Tighten the nuts with a socket wrench until the nuts begin to compress the wood. Repeat this process to add 4 carriage bolts to each of the remaining 5 leg assemblies and secure them.
Step
21
Position a Leg Assembly over the Joint Between Seat Sections
Position a leg assembly directly over the joint between the seat planks in two adjoining sections of the bench. You arranged the seat planks in their hexagonal design earlier, face down on the patio or driveway. While all the sections are arrayed, you are only working with two sections in this step.
Step
22
Attach the Leg Assembly with Screws Driven Diagonally
Attached the leg assembly by driving screws diagonally through the braces and legs into the underside of the seat planks. You may find that pre-drilling the angled holes in the leg assemblies make this task easier. Repeat this process to attach leg assemblies to the other ends of the two joined sections. On completion, you will have a single module that consists of two seat sections with three leg assemblies attached. This attachment is not strong.
Step
23
Support the Joined Sections and Set Them Upright
Support both the ends and the middle of these joined sections while you turn them right side up.
Step
24
Countersink Holes for the Next Set of Screws
Countersink holes in the top of the seat planks for the next set of screws that will add strength and rigidity.
Step
25
Drive Screws Through the Holes and Planks into the Braces
Drive the screws from the top of the seat into the countersunk holes, through the seat planks and into the cross braces below. Countersinking the heads will prevent people from sitting on them and tearing clothing. Repeat this process to assemble and secure another pair of seat sections. You now have two assembled modules and two un-attached seat sections that consist of loose planks.
Step
26
Position the Seat Modules Around the Tree
Position the two assembled modules around the tree, leaving a gap on each side for one of the un-attached seat sections. You may need to try several positions to find the most level footing for the legs without having the legs stand on top of a root at ground level. We do not want to cut the bench legs and we cannot cut the roots of the tree.
Step
27
Dig Away Soil to Make a Flat Footing
Dig away enough soil to allow each bench leg to rest on a flat and level surface. You may be able to slip small pavers beneath the legs to give them a more stable footing and offer more protection against water seepage up the legs. The modules should now be level and exactly positioned to attach the remaining seat sections...
Step
28
Attach the Remaining Seat Planks to Connect the Seat Modules
Lay the other seat planks (outside, middle, and inside) in position between a pair of seat modules, and drive in countersunk screws to secure them. Repeat this process on the other sides of the modules.
Step
29
Apply Water Sealant
Apply a coat of water sealant to preserve the redwood and extend the life of the bench.
