12×20 Gambrel Shed Roof Plans

This step by step diy project is about 12×20 gambrel roof plans. This is PART 2 of the shed project where I show you how to build the barn style roof for the storage shed. This shed has overhangs to the front, back and on the sides, so you protect the walls from water damage. Take a look over the rest of my woodworking plans, if you want to get more building inspiration.

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

12×20 Gambrel Shed Roof Plans

Building-a-12×20-barn-shed

Cut + Shopping Lists

• H – 4 pieces of T1-11 siding – 48″x62″ long, 2 pieces – 48″x72″ long SIDING
• I – 4 pieces of 2×4 lumber – 60″ long 11xTRUSS
• I – 8 pieces of 2×4 lumber – 60″ long, 16 pieces – 3 3/4″ long 2xOVERHNAG
• J – 8 pieces of 1×8 lumber – 60″ long, 8 pieces of 3/4″ plywood – 48″x96″ long, 4 pieces – 48″x48″ long, 8 pieces – 12″x96″ long, 4 pieces – 12″x48″ long ROOF
• K – 450 sq ft of tar paper, 450 sq ft of asphalt shingles ROOFING
• R – 8 pieces of 1×6 lumber – 60 1/4″ long, 4 pieces – 128″ long TRIMS

• 54 pieces of 2×4 lumber – 6′
• 6 pieces of 2×4 lumber – 8′
• 8 pieces of 1×8 lumber – 6′
• 8 pieces of 1×6 lumber – 6′
• 4 pieces of 1×6 lumber – 12′
• 6 pieces of T1-11 siding – 4’x8′
• 1 piece of 1/2″ plywood – 4’x8′
• 13 pieces of 3/4″ plywood – 4’x8′
• 2 1/2″ screws, 3 1/2″ screws, 1 5/8″ screws
• 4d nails, 6d nails, rafter ties
• wood filler , wood glue, stain/paint
• 450 sq ft of tar paper, 450 sq ft of asphalt shingles

Tools

 Hammer, Tape measure, Framing square, Level

 Miter saw, Drill machinery, Screwdriver, Sander

 Safety Gloves, Safety Glasses

Time

One week

Related

• PART 1: 12×20 Gambrel Shed Plans
• PART 2: 12×20 Gambrel Shed Roof Plans
• PART 3: Gambrel Shed Doors & Trims Plans

How to build a 12×20 gambrel shed roof

Gambrel-rafters-12-ft

The first step of the shed roof project is to build the rafters for the trusses. In order to get a professional result, you need to use a miter saw and to make 22.5 degree cuts to both ends of the beams. AS you can notice in the diagram, you also need to make birdsmouth cuts to the rafters that go on the top of the side walls. Take accurate measurements before making the cuts.

Gussets

Lay the rafters on a level surface. You can make a simple jog so you speed up the process. Use 1/2″ plywood for the gussets and follow the instructions in the diagram for a professional result. Align the edges flush and insert 1 5/8″ screws to secure the trusses together tightly.

Fitting the trusses

Fitting-the-trusses

Fit the trusses to the top of the shed frame, placing them every 24″ on center. Plumb the trusses with a spirit level and then secure them into place with rafter ties.

Fitting the gambrel end supports

Use 2×4 lumber for the gambrel end supports. Make cuts to the top of the supports and then drill pocket holes at both ends. Fit them into place and then secure them into place with 2 1/2″ screws.

Gable end panels

Cut the T1-11 siding panel at the size and shape highlighted in the diagram and then secure them into place with 6-8d nails. Insert the nails every 8″ along the framing.

Fitting the overhangs

Building the overhangs

Build the overhangs for the front and the back of the shed from 2×4 lumber. Drill pilot holes through the rafters and insert 2 1/2″ screws into the blockings. You can adjust the size of the blockings to suit your needs.

Fitting the overhangs

Fit the overhangs to the front and to the back of the shed. Align the edges flush. Drill pilot holes through the overhangs and insert 3 1/2″ screws to lock them into place tightly.

Fitting the roof sheets

Cut and fit the 3/4″ plywood sheets to the roof of the gambrel shed. Align the edges with attention and insert 1 5/8″ screws every 8″ along the rafters, so you can lock them into place tightly. Leave no gaps between the sheets for a professional result.

Fitting the roof trims

Fitting the front and back roof trims

Fit the 1×6 decorative trims to the front and to the back of the gambrel shed. Make the angle cuts and then secure them into place with 2″ nails.

Fitting the roofing

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.

Side roof trims

Fit the 1×6 trims to the sides of the storage shed. Use 2″ brad nails to secure the trims into place tightly.

12×20 Gambrel Shed Plans – Back view

Make sure you take a look over PART 1 of the project for the floor and wall frame plans, and PART 3 for the door plans.

12×20 Gambrel Shed Plans – Front view

If you are here, I recommend you to take a look over the rest of the shed plans, as well, HERE.

This woodworking project was about 12×20 gambrel 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.

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