Benches provide easy outdoor seating solutions for porches or decks and you can build them quite simply. Built-in benches go in a wall recess, with three walls to attach to or they go onto one wall attached from the back. For outdoor settings, slatted benches are ideal, because the slats allow for moisture to dry faster, so wood does not weather as fast.
Decide on the dimensions of the bench. For example, to make a 20-by-60-inch bench. Cut two lengths of the 2-by-3-inch lumber to 60 inches and two to 20 inches. Mitre the ends to 45 degrees. Form the planks into a rectangular frame and secure them with two 3-inch screws through each corner.
Measure up 16 inches from the floor and mark a level line, 60 inches long, where you want to secure the bench. Use the stud finder to locate the wall studs along the line and make a mark for each stud.
Place the frame against the level line on one of its 60-inch sides. Secure the frame to the wall with the 3-inch wood screws, two at each stud point. Measure the distance between the front of the frame and the start of the wall -- this will be an angled line of 45 degrees.
Cut three lengths of 2-by-3-inch lumber to this length and mitre the ends to opposing 45 degrees. Place one end of a plank flat on the wall where it meets the floor and one end on the underside of one end of the bench frame -- the opposing angles will allow for one end of the plank to be flush with the wall while the other is flush with the frame.
Secure the plank with two 3-inch wood screws into the wall and two into the underside of the bench frame. Repeat on the other end of the bench and in the centre of the bench to complete the three supports.
Cut the 1-by-3-inch lumber into 10 lengths of 65 inches for the bench slats. Center the slats over the frame, with a 1/8-inch gap between them. The last slat will overlap the edge of the frame. Secure the slats with two 2-inch screws through each end of the slat into the frame ends.
Apply two coats of wood stain to the bench, allowing the stain manufacturer's recommended drying times between coats.