This step by step diy woodworking project is about a 18×18 outdoor pavilion lean to roof plans. This is PART 2 of the large 4 post square pavilion project, where I show you how to build the lean to roof with a 6:12 pitch. Take a look over the rest of my woodworking plans, if you want to get more building inspiration. Premium Plans for this project available Here. Check out the Shop, as well, for full list of Premium Plans.
When buying the lumber, you should select the planks with great care, making sure they are straight and without any visible flaws (cracks, knots, twists, decay). Investing in cedar or other weather resistant lumber is a good idea, as it will pay off on the long run. Use a spirit level to plumb and align the components, before inserting the galvanized screws, otherwise the project won’t have a symmetrical look. If you have all the materials and tools required for the project, you could get the job done in about a day.
Projects made from these plans
18×18 Lean to Pavilion Roof Plans
- G – 12 pieces of 2×10 lumber – 20′ long RAFTERS
- I – 4 pieces of 1×8 lumber – 10 ft long, 2 pieces – 144 3/4″ long, 2 pieces – 120 3/4″ long TRIMS
- H – 8 pieces of 1/2″ plywood – 4’x8′ long, 5 pieces – 4’x6′ long ROOF SHEETS
- K – 500 sq ft of tar paper, 500 sq ft of asphalt shingles ROOFING
- 12 pieces of 2×10 lumber – 20 ft
- 4 pieces of 1×8 lumber – 10 ft
- 2 pieces of 1×8 lumber – 12 ft
- 2 pieces of 1×8 lumber – 14 ft
- 13 pieces of 1/2″ plywood – 4’x8′
- 3/4″ roof nails
- 500 sq ft of tar paper, 500 sq ft of asphalt shingles
- rafter ties
- 1 5/8″ screws, 2″ nails
- 2″ nails
- 1 1/2″ structural screws
- wood glue, stain/paint
- PART 1: 18×18 Lean to Pavilion Plans
- PART 2: 18×18 Lean to Pavilion Roof Plans
How to build a 18×18 pavilion lean to roof
Use 2×10 lumber for the rafters. Use a miter saw to make the cuts to the boards. Smooth the edges with sandpaper. Make the notches to the rafters, as shown in the plans. Mark the lines before doing the cuts.
Fit the rafters to the top of the pavilion, using the information from the diagram. It is important to space the rafters properly (every 24″ on center), otherwise you won’t be able to attach the roofing sheets. Use rafters ties to lock the rafters to the beams. Use 1 1/2″ structural screws for the rafter ties. Secure the rafters to each of the 3 support beams.
Use 1/2″ plywood for the roof of the pavilion. Cut the sheets at the right dimensions and then lay them to the top of the pavilion. Leave no gaps between the sheets and then insert 1 5/8″ screws, every 8″ along the rafters, so you can secure them into place tightly.
Use 1×8 lumber for the side roof trims. Attach the slats to the sides of the pavilion and align the edges flush. Use 2″ nails to secure the trims to the ends of the rafters, as shown in the diagram. Leave no gaps between the components, as shown in the diagram.
Fit 1×8 trims to the front and back of the pavilion. Align the edges with attention and insert 2″ nails to lock them into place tightly. Make the angle cuts with a miter saw.
Cover the roof with tar paper and then install the asphalt shingles. Make sure you also install the appropriate drip edges, so you can seal the shed roof. Read the manufacturer’s instructions for a tight fit.
Last but not least, you need to take care of the finishing touches. Therefore, fill the holes with wood putty and then smooth the surface with 120-220 grit sandpaper.
Apply a few coats of paint / stain to enhance the look of the pavilion and to protect them from the elements.
This pavilion features a lean to roof with a 3:12 roof pitch. If you need a shelter for your outdoor relaxation area, with only 4 posts and generous openings on all sides, you can follow these plans.
Don’t forget to take a look over PART 1 of the project, so you learn how to build the frame of the 18×18 4 post pavilion. This pavilion is sturdy and it features a very elegant design that puts and emphasis on cost efficiency and durability. Premium Plans for this project available Here. Check out the Shop, as well, for full list of Premium Plans.
This woodworking project was about 18×18 backyard pavilion lean to roof plans. If you want to see more outdoor plans, check out the rest of our step by step projects and follow the instructions to obtain a professional result.