The completed shed with a slanted roof image first. Slant roof style is also known as a skillion, shed or lean-to. It is a single sloping roof and can be thought of as half of a pitched roof.
When I was in the process of moving to my new house, I knew that I couldn’t take my shed with me. It was my first one! It was a 6×8 beauty with a gable roof and a double door. It took almost 6 months (ugh) for me to complete. I was devastated!
To make up for my loss, I consoled myself with the knowledge that I’d need to build a new storage shed to house all my stuff. I’d accumulated a snow blower, lawn mower, generator and much more. It would be my second shed in 2 years. My new baby!
In this post, I’ll walk you through the step-by-step process of building my new shed from scratch.
- How to Build a Slanted Roof Shed: Step by Step
- Step 1: Gathering Requirements
- Step 2: Check Local Law Restriction
- Step 3: Choose Size and the Style of the Shed
- Step 4: Determine a Location for the Shed
- Step 5: Prepare the Construction Site
- Step 6: Build Shed Foundation
- Step 7: Build Shed Floor
- Step 8: Building the Walls
- Step 9: Shed Wall Sheathing
- Step 10: Build a Skillion Roof
- Step 11: Build Double Shed Doors
- Step 12: Frame the Windows
- Step 13: Install Siding
- Cost of DIY Building 12×14 Storage Shed
- Final Thoughts
How to Build a Slanted Roof Shed: Step by Step
Step 1: Gathering Requirements
As I began thinking about my new shed, I considered my needs. I decided to build a bigger shed with more space. I wouldn’t have to move the lawn mower to get to the ladder, or the snowblower to dig out the generator. I’d even have space to store some building materials instead of in the garage.
I planned out my requirements; I didn’t want any fancy features or dormers. I wanted something practical. Thinking about my other shed, I made a list:
- Due to the climate and a lot of snow, it needed a greater slope.
- Something easy and practical I could build on my own.
- Easy to install roofing materials.
- I didn’t want my shed sitting on the ground.
- Elevated would mean drier and it would last longer.
- Easy and cheap to install.
Step 2: Check Local Law Restriction
My first step was to look up the local building regulations for some answers:
- Do I need a building permit?
- What is the greatest size shed I can build without, and with, a permit?
- Are there any restrictions on building materials?
- Any setbacks?
- Is there a maximum height for a shed?
- Any requirements on door widths?
I then checked with the local utilities to ensure my shed wouldn’t interfere with their services. To be safe, I also checked with my neighborhood association to see if they had any restrictions.
According to my town regulations, I could build a shed up to 12×14 without a building permit. I emailed the local building department to see how they measure the shed size; by outside perimeter foundation footprint, or the roof projection.
They responded quickly and politely. They confirmed that I didn’t need any permits and included other helpful information. The size of the shed would be calculated by the foundation footprint. Also, the maximum height of a shed, measured from ground level to the highest peak of the roof, is set at 14′ and must never exceed the height of the house.
The regulations allowed a storage shed to be built in the side yard, backyard, or in the rear setback; but never over the septic field. Included in their reply was also a list of approved materials for exterior siding which was useful.
Step 3: Choose Size and the Style of the Shed
Here’s my setup: I reviewed what I needed to fit in the shed today, considered a few wants for the future, looked at my budget, and came up with the size. I’d seen a lot of sheds but had some specific ideas in mind, after doing some research; I came up with my shed style.
I decided to take full advantage of the regulations and build a 12 x 14 shed.
I wanted a simple roof. I didn’t want ridges or valleys which are a lot of work and can leak. I decided on a Slanted Roof. It’s similar to a shed or lean-to roof, or a clerestory roof, but has one visible difference. It has a greater slope. Basically, a slanted roof style is a flat roof tilted high up at one edge to create a very steep slope.
- Significantly cheaper to build than a gable or multi-slope roof since there’s less material in the roof.
- No ridges or valleys to leak.
- Faster and easier to build. No complicated angles or cuts.
- A higher wall on one side for ladders or storage.
- Clear roof space without truss or rafters.
- Sheds rain and snow quickly.
- Expensive to convert a mono pitched roof to a multi-slope roof since all walls need to become the same height.
- Snow can build up against the lower roof wall and cause dampness or rot in the wall.
- Fast run-off of rain or snow can cause ground erosion behind the shed.
Step 4: Determine a Location for the Shed
The next step is the most important part: find the best location for my shed.
The building regulations require the shed to be a minimum of 5’ from the property line, 5’ from the house, and 5’ from any other buildings.
I decided to place my shed 7’ from the fence with my neighbor. It would hide their shed and give the trees room to grow. It also placed the shed closer to my driveway which would make it easier to get my snow blower into action.
Step 5: Prepare the Construction Site
Once I decided on the site for my shed, I cleared the area of ground cover. I added 2’ on each side of the shed perimeter and hammered in wooden stakes at the corners to give me the area I needed. I removed any sod and the top layer of soil, and then slightly compacted the site to pack down any loose soil.
Step 6: Build Shed Foundation
One of the important decisions when building a shed is the foundation. It provides a flat, level, stable base on which to build your shed. The foundation also helps to keep the shed off the ground preventing dampness and rot.
I decided to use concrete deck blocks like I’d used on my first shed. I used adjustable 4×4 steel deck supports which fit into the deck blocks to make leveling easier. I found these on sale at my local home improvement store but you can find similar deck supports on Amazon.
Why I choose this type of foundation?
- Easy to build a stable base for the shed
- An inexpensive base, even with the ground preparation and gravel.
- The shed is off the ground allowing underneath ventilation and clean storage on the gravel.
- The main benefit, it’s very easy to level the base during the construction. Also, if the ground settles and any of the blocks sink the steel deck supports make it easy to re-level.
Here’s the plan of foundation
I used 24 deck blocks and 24 adjustable 4×4 deck supports. I wanted to make sure nothing would make the floor sag…ever! I could almost store a tank in my shed!
If I were to do it again, I’d reduce the number of blocks and supports by half and add galvanized joist hangers for blocking to add structural rigidity to the floor frame. The total and linear load for #2 grade 2×6 on a 4’ span is 303 pounds per linear foot.
It is an excellent foundation for motorcycle sheds or sheds with heavy machinery, like a lawn tractor, but for my needs it was overkill.
Once I had the deck blocks and the adjustable 4×4 supports, I needed to incorporate the supports into the blocks. Using concrete mix and following the step by step process I secured the supports into the blocks.
Here are the steps:
Picture 1: Clean any loose material from the patio blocks.
Picture 2: Clean any oils or grease off the adjustable 4X4 support.
Picture 3: Disassemble the support.
Picture 4: This is how I chose to install the supports.
Picture 5: With the supports installed this way there would be more rigidity and greater support.
Picture 6: To keep concrete out of the bolt column I taped it closed.
Picture 7 & 8: Wet the concrete block to form a better connection with the new concrete. Fill the hole and slots in the deck block, then push the taped end of the 4×4 support into the hole in the concrete block.
Picture 9: Ensure the support plate is angled so it is resting on the concrete block as well as the new concrete. Clean up any mess and smooth the fresh concrete. Now let the concrete cure.
I recommend laying out all the blocks together and doing the same step to each block before moving to the next step.
While the blocks are curing, put down the garden cloth and spread out a level layer of gravel.
I laid out the deck blocks according to the plan where they would line up with the floor structure. Leveled the blocks and used the adjustable supports to level the floor structure.
Step 7: Build Shed Floor
Now the fun and work begin!
What You’ll Need :
Gather the tools you’ll need so you don’t have to go looking for them later: hammer, saw, level, wrench, screwdriver, tape measure and pencil. Have the nails and screws handy too.You don’t need any fancy tools, but a chop saw makes short work of cuts and angles and a circular saw is great for cutting plywood. I also got really lucky; my local home improvement store was liquidating Paslode Impulse cordless framing nailers. I was able to score one and it saved me a lot of time.
The floor frame was actually simple; 6 pressure treated 2x6x14’ and 2 pressure treated 2x6x12’ planks. My local supplier didn’t have any 14’ planks so I got 16’ instead. I knew the extra lumber wouldn’t go to waste.
The adjustable 4×4 deck supports are designed for true 4×4 lumber so I needed to add spacers. The leftover pieces from the 2x6x16’s came in handy.
I sealed the end cuts with CopperCoat Green wood preservative.
To secure the adjustable supports, joists and blocks together, I used #8 x 2 in. deck screws. It is a good idea to check that the joist structure is square before securing it.
I added pressure treated 2×6 blocks about every 4’ to create a grid style floor base. The blocks prevent the floor joists from twisting under load and provide more support so there’d be less bounce between the joists. I used my new nailer to fastening the boards and blocking with ring shank galvanized framing nails. Definitely a time saver!
The grid created by the blocking.
Before I began to attach the 3/4 inch pressure treated plywood, I again checked that the floor structure was square and level.
A 12×14 base means some the plywood would have to be cut. I also didn’t want to have to crawl around under the shed someday to tighten the adjustable 4×4 supports.
With this in mind, I planned the layout for the plywood so I can remove 2 inside pieces
and have access to all the inner blocks.
I used #8×2 inch deck screws to fasten the plywood. All I have to do to adjust any of the inside supports is remove one or both of the plywood pieces and tighten or loosen the necessary nut(s).
Step 8: Building the Walls
When planning my shed I determined where windows and the doors would go. I decided on 2×4 lumber on 16-inch centers for the walls, and 2×6 for the rafters. I’d also need 2×6 lumber for the window and door headers. I then laid out the stud plan for the wall construction. This made it easier to make a materials list of what needed to be purchased.
There are several methods to purchase lumber. You can call your local supplier and have them deliver the materials on your list. This works great if you don’t have access to a truck or a trailer. But, you get what they pick which may not be what you’d pick if doing it yourself. There may also be a delivery charge.
If you have access to a truck or trailer, then you can pick your lumber…usually. Some lumber yards don’t want you handing the lumber for various reasons. Most Box Stores allow you to pick your own lumber though. If you can pick your own lumber, here are a number of things to watch for.
Twists: Look along the narrow edge of the lumber, if it has a noticeable twist, put it back. It will be difficult to straighten and makes attaching drywall or sheathing difficult.
Bend: Look along the narrow edge again, if the lumber bends slightly to the left or right, it is still usable. It can straighten with blocking, or when nailed or screwed to a straight piece; as in a doubling up for a trimmer or corner.
Warped, Curved, or Arched: Look along the flat length of the lumber. If the lumber bends slightly to the left or right it will form an arch or a dip horizontally. It is still useable for joists or the trusses/rafters, not great as a stud. Ensure they are laid arch up; the weight of the floor or roof material (gravity) may pressure it straight.
Pro Tip: Buy extra lumber for blocking (noggins) the walls at the 4-foot height. It keeps the studs from twisting and gives wood to nail sheathing or drywall to. It also provides shelving between the studs.
Pro Tip: Always measure the dimensions of your lumber. If you need 12 feet and get 10 instead, you won’t be happy.
With the lumber at the build site, I was ready to begin. Using the plywood floor as a work table, I paired the top and bottom plate for the back wall side by side flat on the deck.
I ensured they were 14 feet long, then following my stud plan I marked where the studs would go, drawing the lines with a small rafter square; marking an X on the correct side of the line where the stud would go.
I carefully measured one stud and cut it to length; remembering that for a 6-ft. wall height I needed to subtract a double top plate and the sill plate. Using that stud, I marked the rest of the studs for that wall and cut them too.
I then laid out the studs between the top and bottom plate, lined them up with the marks, and reached for my hammer. My handy dandy nailer made short work of nailing the plates to the studs. Once the wall was built, I slid it off the deck and leaned it out of the way against the fence.
I used the same process to build the windowless side wall. Remembering to cut the top and bottom plates 7 inches short of 12 feet so they fit between the front and back walls.
The studs were the same length as those in the back wall. After nailing it together, I ensured it was square and nailed two opposing diagonal 2x4s to hold it square. Nailing it to each stud and plate it crossed. I then slid it out of the way and leaned it against the tree.
Pro Tip: Use screws to attach the diagonal braces, easier to remove.
The side wall with the window had a few differences. I used a double 2×6 header above the window. Sandwiched between the 2x6s I used ½” plywood spacers.
The header transfers the weight of the structure above the window and carries it through the king stud-trimmer stud combination to the floor. The distance between the header and the rough sill and the two trimmer studs is the rough opening for the 27 ½” x 27” high window.
Don’t forget the cripple studs between the rough sill and the bottom plate of the wall. After careful measuring and cutting, I repeated the steps followed for the other end wall.
The last wall was the tallest (9 feet) and heaviest wall with the most openings. Once built it would be the first to erect. I laid out the bottom plate and marked the stud locations, including king and trimmer studs for the door and window.
This window would be 27 ½” x 37 high. Regulations restricted door size at a maximum of 6 feet; so I framed the rough opening for a 76 ½” high x 6’ wide door.
I framed the two ends of this wall with triple studs. The outer stud connected the end of the top plate and bottom plate. The middle supported the end of the top plate to the bottom plate.
And the inner stud supported the double sill plate of the upper windows, which acted as the top plate for the studs. I used a double 2×6 header above the door and the window with plywood spacers sandwiched between.
Using the skillion roof design meant I could have windows up near the eves. The top plate for the big wall I rotated on edge and used ½” spacers between the two 2x4s.
This made the 2x4s a header to carry the roof weight above the high windows, and also a top plate. I used double 2x4s to support the stud wall top plate and the wall top plate/beam.
The double 2×4 supports were equally spaced across the wall creating 5 openings 29 ¾” wide x 14 ¾” high. Once I had this wall together, I ensured it was square and again nailed two opposing diagonal 2x4s to hold it square. I was now ready to stand the walls up.
Four stud corner: I used a four-stud corner to create a strong corner and post for supporting the roof. This configuration also provides more material for nailing exterior sheathing to, and provides support for attaching interior drywall (if needed).
Attach blocks along the perimeter of the floor to prevent the wall from sliding off the base as you lift it into position.
The Challenge: How to raise the heavy front wall alone (without a helper)?
My Solution: With a car jack!
I realize there are other ways to lift a wall by yourself, and mine wasn’t maybe the safest, but it was creative and it worked. No matter what method you choose, know your escape routes to safety!
On a day that wasn’t windy, I lifted the top edge of the wall and put some blocks under it. Once it was high enough off the floor, I slid the car jack under it.
I secured a couple of straps to the upper beam so I could prevent the wall from leaning out once it was up. I used cut-offs from building the wall so I had different lengths for bracing and lifting. Before each lift with the car jack, I ensure it wouldn’t roll too.
Next time I’ll attach a long 2×4 brace on the outside of both ends and lay it out on the ground so that they drag in toward the foundation as the wall lifts.
As the wall lifts, higher they act as braces too.
With the wall vertically leveled, I secured diagonal braces to the upper part of the wall and to stakes hammered into the ground.
Once the big wall was level and secured in place, I nailed the bottom plate to the floor. I then lifted the end walls into place, leveling and nailing them to the floor and front wall.
I placed the bottom plate of the back wall onto the floor. Nailed in perimeter blocks to prevent it from falling off the floor, and lifted the wall up until it butted into the two end walls.
I attached nailing blocks to the floor deck and leveled and braced the walls. The gable ends were built in place on the end walls.
Related: Shed Insulation Guide
Step 9: Shed Wall Sheathing
I used 23/32 in. x 4 ft. x 8 ft. T&G OSB to sheath the walls with 2” deck screws to fasten them in place. It was a bit of fun installing it alone. 4 ft. x8 ft. sheathing fits horizontally or vertically on 16” center stud walls.
I went vertically for two reasons. I wouldn’t have to lift up a sheet to sit on another sheet; and less chance of moisture sitting on a vertical seam vs a horizontal seam.
Pro Tip: Attach a level plank or block to the perimeter of the platform face at the height the sheathing will start. This provides a rest for the sheathing to sit on and frees up a hand or two for fitting the T&G and for fastening.
Pro Tip: Ensure the groove is clear and open before putting the sheet up; saves a lot of frustration.
I used felt paper (tar paper) to wrap the walls for several reasons. Tar paper is cheaper and dries faster than Typar. A 3’x72’ roll of #15 felt paper costs around $15, a 3’x100’ roll of Typar is about $50 in my local. I used 2 rolls of felt paper.
I began wrapping the shed at the bottom and worked my way up; overlapping the top layer over the bottom to shed any moisture away from the wood.
I used a hand stapler and a lot of galvanized staples. Next time I’ll use a hammer stapler, it’s easier on the hand.
Step 10: Build a Skillion Roof
The material you chose to cover your roof with is very important. It is what keeps water or snowmelt from percolating through into your shed. It protects the wood of your shed from rot and bug and rodent damage, and from the elements. An important decision with many choices; asphalt, steel, aluminum, clay, slate, or cedar shake.
There are advantages and disadvantages to all roofing materials, do your research and make your decision. I chose asphalt shingles. The price was right, color acceptable, and with the single slope roof design and direction my shed faced, only my neighbor would see them.
- Cheap! Asphalt shingles are one of the least expensive roofing materials. They frequently go on sale too.
- Easy installation even for a beginner. Follow the instructions on the bundle wrapper or check out videos online.
- Asphalt shingles are widely available in different colors and textures.
- Will degrade with time; may last 7 to 20 years before needing to be replaced.
- Are a petroleum product so an environmental issue and cost when disposing of them.
- Susceptible to wind and heat damage. They transfer the solar gain into your building.
If your shed is fairly airtight, you’ll need to put in ventilation; especially if storing gasoline or pesticides in it. No sense poisoning yourself. Add a vent in each gable end near the roof line.
This allows cross ventilation and the roof overhang adds some protection to the vents. I went with the natural ventilation through the gaps between the roof and the walls. I may need to screen them to keep bugs and critters out though.
I used 2x6x16ft pine for the rafters.
Angle cut the ends, notched for the walls, then installed them at 16” centers.
Simpson Strong-Tie 18-gauge hurricane ties to help secure each rafter.
I built ladder ends to go over the gables for the overhang at each end. I then added blocking between each rafter every 4 ft. to support the edges of the sheathing, and to prevent the rafters from twisting under snow load.
The fascia boards across the ends of the rafters prevent twisting and provide a finished edge.
I sheathed the roof with 23/32 in. x 4 ft. x 8 ft. T&G OSB. A fun challenge is doing it alone. I covered the OSB with tar paper; starting across the low edge first and working in overlapping layers to the high edge.
I left enough to fold over the fascia boards. I used aluminum nails to attach the aluminum drip edge. The aluminum fascia slides up under the drip edge and is attached to the fascia board with aluminum nails. It often hangs ½” below the fascia board and the soffit sits on the bottom lip.
Follow the instructions on the shingle wrapper for proper installation. I used 1½” electro-galvanized roofing nails to attach the shingles.
Pro Tip: Before lifting sheathing onto the roof, build yourself a “ladder”. Lean and secure two 2x4s or 2x6s planks against the fascia board of the low wall; angled from the ground to the roof.
Attach a horizontal “step” to the two planks upon which to rest the sheathing. The wider the “step”, the more pieces it will hold. Place several pieces of sheathing onto the step so the stick up above the roof line. You can then stand on the wall top plate or the rafters and lift each piece up as needed; less going up and down a ladder.
Pro Tip: Use pressure treated lumber for the fascia boards and end rafters.
Step 11: Build Double Shed Doors
Ever scraped your knuckles trying to carry something through a door?
I built my shed with a 6’ wide double door since it was the largest the Regulations allowed. I can open one or both. It’s much easier to move equipment in or out of the shed.
Mine open outward, so I don’t waste storage space inside. Also, it’s easy to seal against the elements and rodents. And I don’t scrape my knuckles.
Remember to cut the sill plate out of your doorway.
I decided to build my own door. I used 1x6x8ft T&G knotty pine for the door. The T&G has low shrinkage, and shouldn’t have gaps or warps in the future. The cross and diagonal braces on the back are leftover 2×4 lumber. The thicker wood makes it stronger and gives more wood for the hinges to attach to.
Cut the pine to length, glue the groove and push together, and then attach to the back braces with 1½” screws. I gave the doors 2 coats of white paint. It covered the knots, but with time some would become visible.
The doors were heavy, so I used 8-inch heavy duty spring T-hinges. The springs would help keep the doors shut.
To improve the security of the shed, I replaced one of the screws in each with a bolt.
Pro Tip: The diagonal braces always point down and into the hanging jamb; never away (apart from old western movies).
Step 12: Frame the Windows
Your shed should have at least one window. It lets light in and makes it easier to see. If it opens, it can also let fresh air in so the door doesn’t have to stay open. The Skillion Roof style makes it easy to put extra windows up high to let light in without making the contents of the shed visible to unwanted visitors.
I cut the felt paper diagonally from corner to corner at the windows and door. Wrapped the felt into the opening and stapled it in place.
I then used 1×4 fence boards painted with 2 coats of white to frame and trimmed out the windows and door.
The windows are made from virtually unbreakable polycarbonate sheets. The front and side windows were cut from 0.118 in. clear polycarbonate sheets. The upper windows are made from 1/4 in. clear multiwall polycarbonate sheet panels.
I used a 7-1/4″ 40-tooth circular saw blade to make the cuts. To avoid scratches, I didn’t remove the protective film from the sheets until the cuts were done. I clamped the panels to my workbench so they wouldn’t vibrate or move. An aluminum guide rail kept my cuts straight.
I installed the window pieces using nailing strips. I added decorative grids to the inside of the lower windows which also add some rigidity to the plastic window.
Step 13: Install Siding
The local building department provided me with a list exterior siding that I could use. Originally I was planning to use T&G pine planks. After calculating the cost and considering the hassle of staining the pine every 2 – 3 years, I went with vinyl siding.
- Cheap! Vinyl is an inexpensive product if you pick beige, white, gray, light blue or khaki. If you want a low volume color or profile, it will cost more.
- Durable! Vinyl is a very forgiving and flexible material. It can take bangs and scrapes and stand up to almost any weather if installed correctly. The color also doesn’t fade.
- Maintenance free; once installed properly the siding seldom requires any maintenance. It may require a hosing down to remove dust or dirt, but no painting or staining every 2-3 years.
- Easy, almost “no-skills-required” installation. Follow the simple instructions and measure carefully, it’s quick and easy.
- It’s also a waterproof barrier for your shed and its contents.
- Extreme temperatures are one of the few disadvantages to vinyl siding. Vinyl will expand at hot temperatures and contract on cold days. This usually isn’t a problem if properly installed. It can shrink and flex without notice. But when cut and installed at cold temperatures, it can warp at hot temperatures. This can make it susceptible to wind damage and looks awful.
- Oil based products can stain vinyl, so be careful when cleaning paint brushes and machinery.
- When installing vinyl, remember that cut edges are sharp. Have some band-aids available.
Installing the vinyl siding was easy. I just followed the manufacturer’s instructions. Even the tools are simple! A hammer and the same galvanized roofing nails used for the shingles. Fiskars scissors to cut the siding, and I rented a snap lock punch to put nail holes where needed.
Begin with the starter strip at the bottom and attach the outside corners. Make sure these are level! Install the flashing and J-channels for the windows and doors, and the under-sill trim too.
Once these were all in place, I installed the siding panels.
The siding project only took me one weekend!
Cost of DIY Building 12×14 Storage Shed
Now for the question how much did this cost me. Right around $3,800.
Five years later:
Building this single sloped roof shed was an excellent learning experience. Preplanning was essential to the build. The shed style allowed more windows near the high wall roofline which adds a lot of light.
The greater roof slope sheds snow and water easily too. I presently have ample space for storage and no squeak or bounce to the floor. And it looks Awesome!
Hopefully, this article has provided you with some useful information on how to build a slanted roof shed. Your comments are appreciated. If you know someone who is thinking about, for example, building a shed to store a bicycle, share with them if you liked it.