12x18 Lean to Shed Roof Plans

This step by step diy project is about 12×18 lean to shed roof plans. This is PART 2 of the large storage shed project, where I show you how to build the lean to roof with step by step drawings. The roof is built on a 2×8 beam framing. Take a look over the rest of my woodworking plans, if you want to get more building inspiration. Remember that you need to select the location for the shed with attention and that you have to comply with a few legal regulations.

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. See all my Premium Plans HERE.

Projects made from these plans

12×18 Lean to Shed Roof Plans

Building-a-12×18-lean-to-shed

Cut & Shopping Lists

I – 2 pieces of T1-11 siding – 48″x16 1/4″ long, 2 pieces – 48″x28 1/4″ long, 2 pieces – 48″x40 1/4″ long SIDING
J – 19 pieces of 2×8 lumber – 168″ long, 16 pieces – 4 1/2″ long RAFTERS
K – 5 pieces of 1/2″ plywood – 48″x96″ long, 1 piece – 48″x48″ long, 1 piece – 48″x72″ long, 2 pieces – 24″x48″ long, 1 piece – 24″x96″ long, 1 piece – 24″x72″ long, 2 pieces – 8″x96″ long, 2 pieces – 8″x72″ long ROOF
L – 300 pieces of tar paper, 300 sq ft of asphalt shingles ROOFING
O – 2 pieces of 1×10 lumber – 120″ long, 2 pieces – 112″ long, 4 pieces – 84 3/4″ long TRIMS
M – 2 pieces of 2×4 lumber – 80″ long, 1 piece – 103″ long JAMBS
N – 1 piece of T1-11 siding – 48″x80″ long, 2 pieces of 2×4 lumber – 48″ long, 1 piece – 41″ long, 2 pieces – 73″ long 2xDOOR
O – 4 pieces of 1×4 lumber – 131 1/4″ long, 4 pieces – 95 1/4″ long TRIMS

20 pieces of 2×8 lumber – 14′
4 pieces of T1-11 siding – 4’x8′
4 pieces of 1×10 lumber – 10′
4 pieces of 1×10 lumber – 8′
9 pieces of 2×4 lumber – 8′
1 piece of 2×4 lumber – 10′
4 pieces of 1×4 lumber – 8′
4 pieces of 1×4 lumber – 12′
9 pieces of 1/2″ plywood – 4’x8′
300 sq ft of tar paper, 300 sq ft of asphalt shingles
2 1/2″ screws, 3 1/2″ screws, 1 5/8″ screws
6d nails
wood filler , wood glue, stain/paint
rafter ties
truss plate
shed hinges

Tools

Hammer, Tape measure, Framing square, Level

Miter saw, Drill machinery, Screwdriver, Sander

Safety Gloves, Safety Glasses

Time

One day

PART 1: 12×18 Lean to Shed Plans
PART 2: 12×18 Lean to Shed Roof Plans

How to build a 12×18 Lean to Shed Roof

Rafters-for-12×18-shed

The first step of the project is to build the rafters for the large lean to shed. As you can see in the diagram, you need to make the birdmouth cuts to the 2×8 beams.

Fitting-the-rafters-for-12x18-lean-to-shed

Fitting-the-rafters-for-12×18-lean-to-shed

Fit the rafters to the top of the tool shed shed frame. Place the trusses every 16″ on center. Use a spirit level to plumb the trusses and fit rafter ties to secure them to the top plates. The rafter ties will lock the trusses into place tightly. This is a strong roof and it is suitable for most climates, but make sure you read the local building codes for more details.

Side roof supports

Use 2×4 supports for the sides of the lean to roof. Drill pocket holes at both ends of the supports and then secure them into place with 2 1/2″ screws.

Lean to side siding panels

Use T1-11 siding for the side roof panels. Cut the panels to the right size and shape and then secure them into place with 6-8d nails. Align the edges flush and insert the nails every 8″.

Overhangs for the lean to shed

Assemble the overhangs for the sides of the roof, using 2×8 lumber. Drill pilot holes through the beams and insert 3 1/2″ screws into the blockings.

Fitting the side roof overhangs – diy large shed

Fit the overhangs to the sides of the lean to shed. Align the edges flush, drill pilot holes and insert 3 1/2″ screws to lock them into place tightly.

Fitting-the-roofing-sheets—large-shed

Cut the roof sheets from 1/2″ plywood. Align the edges flush and then insert 1 5/8″ screws, every 8″ along the rafters, so you lock them into place tightly. Alight the edges flush and leave no gaps between the sheets, for a professional result.

Front and back roof trims

Use 1×10 lumber for the front and back roof trims. Use 2″ brad nails to secure the trims into place tightly. Align the edges flush.

Side roof trims

Fit the 1×10 trims to the sides of roof. Align the edges flush and insert 2″ nails, so you secure the trims into place tightly. The trims are easy to install and it will add unique appeal to the shed.

Fitting the roofing to the lean to shed

Cover the roof of the shed with tar paper and then install the asphalt shingles. Use drip edges to make sure the roof is waterproof.

Double doors jambs

Use 2×4 lumber for the jambs. Attach the jambs around the double door opening and then secure it into place with 2 1/2″ screws. Make sure the edges are flush.

4-ft-shed-door-plans

Use T1-11 siding sheets for the door panels. Use 2×4 lumber for the door frame. Drill pocket holes and assemble the door frame before attaching the panels. Use 2″ nails and glue to attach the panels to the frame.

Fitting the double doors

Fit the doors to the opening, using hinges to secure them to the jambs. Use a latch to keep the doors locked.

Side window trims

Install the window to the side of the shed frame. Attach the 1×4 trims around the shed window, to enhance the look of the shed.

Corner shed trims

Last but not least, you need to take care of the finishing touches. Apply a few coats of paint over the exterior of the shed to protect the components from the elements and to enhance the look of the project. Apply a few coats of paint over the trims.

How-to-build-a-12x18-lean-to-garden-shed

How-to-build-a-12×18-lean-to-garden-shed

12×18 Lean to Shed Plans – back view

You should take a look over PART 1 of the project, where I show you how to build the frame of the 12×18 storage shed. I have tons of lean to shed plans on the blog, so you should take a look over the alternatives HERE. You can build this shed in a few weeks and save tons of money, as compared to buying a retail one. To make a cost estimate for the shed, you need to compile the materials lists for PART 1 and PART 2.

This woodworking project was about 12×18 shed roof plans free. 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.