Building a backyard lean-to out of landscape timbers is similar to stacking Lincoln Logs. With a few simple tools, the structure can be raised in a few moments and will provide a sturdy shed, a shelter for a bench or a play structure for kids. Here's how it goes together.
Notch one end of two landscape timbers 75 mm (3 inches) from the end. Make two cuts halfway through the timbers the width of a timber apart. Use the heavy hammer and chisel to break the notch free between the cuts. Drill half inch holes in the opposite end of both timbers 75 mm (3 inches) from the ends.
Lay both timbers 225 cm (7 feet 6 inches) apart, notches up and facing the same direction. Insert the two all-thread rods through the holes in the ends opposite the notch, and bolt them underneath the timber.
Notch a timber on both ends so the notches line up with the two base timbers. Cut the notch the same way as above. Lay the unnotched side of the timber in the notches of the two base timbers with the notches on the crosswise timber facing up.
Notch two more timbers the way you did the first pair and drill holes in the opposite ends to match. Thread the logs down over the rods and into the notch on the crosswise timber with the notches on the front-to-back pair of timbers facing up.
Repeat notching the crosswise timber and setting it notches up and then notch and drill the front-to-back timbers. Alternate until you build a stack eight feet tall.
Notch the top front-to-back timbers at the front with the rod coming up through the centre of the notches. Add a crosswise timber with notches.
Notch and drill holes in a single timber and thread it across the front between the threaded rods with the notch up and threaded into the notch atop the side walls.
Drill holes in two side timbers and thread onto the front rod and let the side timbers rest in the front and rear notches. Do not notch these timbers.
Drill one end of each timber and stack five logs, one straight on top of the other, on each end. Don't notch them at the back end, but do notch them at the front and drill for the threaded rod. Do not add any more timbers across the back. For now leave the ends of the side timbers toward the back unattached.
Continue adding front crosswise timbers. Notch as before, sitting the timber in the notch at the front of the side timbers with its own notch facing up. Continue notching and stacking in this fashion until you have 5 layers, sides and front. Don't notch the top logs. Recess the hole in the top log before you thread it over the rod. Screw on the washer and nut, and cut off excess rod above the wood. Tighten the nuts as tight as you can without splitting the timbers.
Toenail the back ends of the side longs to temporarily hold them in place. Leave nails sticking up so you can pull them out later. Stretch a chalk line along the sides between the lower back corner and the top of the highest front landscape timber. Cut the logs at an angle and remove the scrap pieces. Toenail the loose ends of the side timbers to one another at the end with the 150 mm (6 inch) nails.
Nail 50 by 100 mm (2 by 4 inch) between the front highest timber and the back highest timber. Position the 50 by 100 mm (2 by 4 inch) joists 350 mm (16 inches) apart from centre to centre following the roof line all the way across, running parallel between the sides. Cut the plywood sheets to the size you want and nail them to your roof.
Cover the roof with shingles if desired, and you are done. You can also run 225 cm (7 foot 6 inch) floor joists between the base logs, toenail them into place, then nail plywood flooring over the joists.