How to Build a Self Draining Garden Bench

The kind of bench you should use outdoors is one that is self draining so when you sit down on it the day after a rainstorm you don’t get wet. This kind of bench is built of 2 X 4s in such a way that the seat of the bench is made out of the group of 2 X 4s on edge with about a half-inch gap between them. In fact the whole bench can be constructed just using 2 X 4s.

The whole bench can be built using 14 8 foot 2 X 4s assuming the length of your seat is  8 feet, otherwise cut to length.  The width of the seat is 12 2 X 4s spaced a half-inch apart, and the other 2 2 X 4s account for the cross bracing.  The legs are made from 4 X 4s cut to length.

The first thing you have to do the two by fours after bringing them home from the lumberyard is to coat them with a waterproof stain. If you are going to build an 8 foot bench the only other thing you have to do is drill a 1 1/4 inch into the 2 X 4s about a 6 inches from each end and one in the middle to accommodate a 1 ¼ dowel that is driven through the 2 X 4s to hold them together. The dowels should also be coated with waterproof stain before they are used. You will need three dowels an inch and a quarter in diameter by 20 3/4 inches long.

To assemble the seat of the bench late one 2 x 4 on the ground inserting the three dowels into the pre-drilled holes solely into the bowels through the first 2 x 4 are flush with its edge. Using some scrap pieces of half-inch plywood as spacers place the next 2 x 4 on the three dowels.  Keep repeating this process until you have used up all the s X 4s.

Lay this finished piece upside down on a flat surface and snap three lines that are parallel to the dowels centers.  With a countersink bore a series of screw guide holes into the centers of the dowels.  Use some flat headed 3/16 X 1 1/4 inch wood screws to anchor all the 2 X 4s to the dowels.  After all the screws are in place fill in their countersunk holes with plastic wood to keep them from rusting.  Remove the small pieces of ½ inch plywood you have used for spacers.  Cut the dowel ends flush with the 2 X 4s and stain their ends.  This part of the project is finished. 

The part you have just fabricated can be used for any number of outdoor projects because it is so basic, use your imagination to develop like projects. One that immediately comes to mind is an outdoor Barbecue using a Japanese Hibachi countersunk into the center of the bench resting on a platform set below the bottom of the bench.

The crosspieces are also made from 2 X 4s that are cut to the finished width of the bench.  Of course these crosspieces are also stained before use.  They are placed parallel to each other with the ends of the bench sticking out 6 inches past the closest crosspiece.  The crosspieces are spaced 3 ½ inches apart.  These are held to the bench using 4 inch lag screws from the bottom of the crosspieces.

The last pieces are the legs that are cut to a convenient length usually 14 ½ inches long.  They can be made from 4 X 4s that are prestained before use.  The legs can also be fabricated from 2 X 4s using two lengths that are glued together using a waterproof glue and clamping them together until the glue sets.

The legs are attached between the cross pieces using 8 – 5/16 x 7” inch carriage bolts with washers and nuts.  These are placed by drilling two holes across the crosspieces and legs, and then slipping the bolts through the holes then “nutting” them down using nuts and 5/16” washers.

Image by Let Ideas Compete via Flickr