Learning how to build a roof yourself can potentially save thousands of dollars on new roof installation costs. But in most cases, building a roof isn’t a do-it-yourself (DIY) job. To give you an idea of the process, our step-by-step guide walks you through how to build a roof safely and correctly, from the initial planning and framing to the material selection involved.

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Planning Your Roof

Before beginning your roofing project, evaluate your existing roof structure, determine the roof style and layout, and obtain the correct permits.

• Evaluate your roof structure: Before building, evaluate your roof’s structural integrity. This involves checking your roof’s support system, such as the roof decking and trusses, to ensure they’re in good condition and can hold the roof’s weight. Any signs of damage to structural components may require additional roof work.
• Determine the roof style and layout: Your roof structure must support the new roof style and layout. If you opt for heavier roofing materials, your roof may require additional support to withstand the extra weight. Common roof styles and layouts include gable, hip, and gambrel roofs. Gable roofs are triangle-shaped, with two sides resting to meet the ridge. Hip roofs have four equal-length slopes that meet to form a ridge. Gambrel roofs are another popular option but are more commonly used on barns.
• Obtain permits: Speak with your local building code office to get approved for a building permit before beginning roof construction. How long it takes to get a permit depends on where you live, but the permitting process for structural work usually takes at least a month.
• Take the proper safety precautions: Roof installation requires properly positioning ladders and scaffolding to provide a safe working platform. Depending on your roof’s pitch, you may need harnesses and anchors to assist. According to the National Roofing Contractors Association (NRCA), a steep-sloped roof with unprotected sides and edges 6 feet or more above a lower level must be protected by either guardrail systems with toeboards, a safety-net system, or a personal fall arrest (PFA) system. PFA gear includes body harnesses attached to a roof anchor by a lanyard.

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Roofing Material Options

Your roofing material will impact the durability, cost, and roof aesthetic. Below, we’ll review common roofing materials and their pros and cons to help you choose the right roof type.

Asphalt Shingles

Asphalt shingles are the most common type of roofing material and one of the most affordable, with the cost of shingle roof installation starting at $80 per roofing square for basic three-tab asphalt shingles and up to $200–$900 per roofing square for architectural asphalt shingles.* During installation, roofers lay and overlap asphalt shingles in rows and secure each shingle with roofing nails.

With regular maintenance, high-quality roofing shingles can last up to 30 years. However, not all asphalt options have long-term durability—and these can be sensitive to extreme temperature changes. Additionally, most asphalt shingles only work on a roof with a slope of 2:12 or greater.

*Article cost data via Angi, HomeAdvisor, and Nachi.org

Metal Roofing

Metal roofs last 40–80 years, which is considerably longer than asphalt shingles. All metal options offer high levels of durability, easy maintenance, and resistance to fire and wind. Metal is also an energy-efficient roofing material, which can help lower your utility bills. However, installing metal is difficult and often requires a specialist. On average, metal roof installation costs $11,383, but materials alone cost between $2–$7 per square foot for galvalume and up to $25 per square foot for copper.

Slate Roofing

Natural slate lasts up to 150 years and comes in a range of styles and colors. Slate is more expensive than other roofing materials, synthetic and hybrid slate are more affordable. On average, a natural slate roof costs $10–$30 per square foot, but prices can go as high as $80 per square foot.

DIY installation of a slate roof can save you up to 70% on the cost of a new slate roof, but slate requires specialty knowledge for proper installation. Slate roofing is fragile—if you don’t know how to install it on a roof, you could break it if it’s handled improperly. Our recommendation is to consult a professional.

Tile Roofing

The pricing for tile roofs is between $2–$10 per square foot. Expect to pay the least for concrete roof tiles and more for clay tiles or terracotta tiles. Your chosen tile roof design and whether you go for interlocking tiles, flat tiles, Spanish tiles, barrel tiles, or another option can also affect the cost. Tiles are eco-friendly and resistant to fire, but they’re very heavy and often require additional structural support. If your roof requires strengthening to hold the extra weight, you can add extra trusses or strengthen existing trusses with additional 2x4s.

Installing tile roofing is complex. Unless you have experience working with tile, most homeowners shouldn’t attempt to install this type of roof on their own and should consider hiring a professional.

In this video, Ask This Old House general contractor Tom Silva compares the qualities of different types of roofing materials.

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Framing Your Roof

A roof’s framing provides its structure and shape. You can choose from a variety of layouts for your roof framing plan using either prefabricated trusses or custom rafters.

Rafters

Roof rafters are typically found in stick-frame roofs, which have several rafters arranged side by side that run from the roof ridge to the external wall’s wall plate. Rafters provide a framework that supports the roof deck and roofing materials. Roofers will custom-cut all necessary lumber on-site and use ceiling joists to secure the rafters and connect them to the exterior walls. The ridge board, or beam, provides extra support at the rafter’s highest point.

Rafters are wider than trusses, with common dimensions like 2×8, 2×10, and 2×12. Rafters are easy to insulate and can offer more headroom in your attic, making it easier to perform a conversion if desired. However, installation often requires a specialist who knows how to accurately measure, cut, and install rafters. If you have the expertise and feel comfortable installing rafters on your own, we recommend using an experienced assistant to lift the rafters into place.

Tips for Measuring and Cutting Rafters

• Before cutting, acquire the span, rise, run, and line length measurements of your roof frame.
• Once you have your measurements, use a pencil and framing square to mark and angle cut lines on the rafter boards to match the roof’s pitch.
• Mark the plumb cut at the top of the rafter where it meets the ridge board. Put the long arm of the framing square on top of the rafter board and draw a line along the outside edge of the longer arm.
• Locate the area where the rafter meets the top wall plate and mark the bird’s mouth cut, which is made of two cuts called the heel cut and seat cut.
• Mark the tail cut located at the opposite end that creates the roof eaves (this depends on the soffit and fascia board).
• Repeat all markings across all rafter boards and use a circular saw to make the cuts.
• Install each rafter on each side of the ridge board on the gable ends.

Trusses

Trusses are triangular prefabricated frameworks with three main components—top chords, bottom chords, and web bracing—that form a webbed pattern to support the roof. The webbing structure allows trusses to support heavier roofing materials while using fewer load-bearing walls.

Roof trusses are DIY-friendly, and some include instructions for spacing and fastening. The lumber used is also less expensive than rafters, and installation requires fewer materials than if you were using rafters. However, trusses are heavy and may require a crane to be lifted onto the roof for installation. Trusses also have fewer design options because of their webbing structure and don’t allow for attic conversions.

When installing trusses, use temporary bracing to erect the roof trusses to prevent them from falling over during installation. A common way to brace trusses is by using 2×4 blocks of lumber before installing sheathing.

Here’s how to build temporary bracing for your roof trusses:

• Cut blocks of 2×4 lumber to span from the top chord of one truss to the top chord of another truss.
• Nail the bracing into the top chords while still following the manufacturer’s layout.
• Install diagonal bracing in a “W” pattern.
• Remove the blocks when installing the sheathing.

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Roof Pitch Considerations

A roof’s pitch can impact your home’s overall aesthetic, drainage, and the materials used during installation. The roof’s slope also affects its ability to drain water, and not all materials work on roofs with a low pitch.

While asphalt shingles aren’t recommended for roofs with a pitch lower than 2:12, you can use flat roofing materials like ethylene propylene diene monomer (EPDM) rubber for very low angles.

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Sheathing Your Roof

Sheathing, also known as decking, is the layer of wooden boards attached to the joists and trusses. Sheathing forms the roof’s outer framework and acts as a support for shingles or other roofing materials. The most common sheathing materials are plywood and oriented strand board (OSB).

Tips for Installing Sheathing

Here’s a step-by-step guide to install sheathing:

• Gather materials, such as safety gear, a tool belt, a hammer or nail gun, roofing nails, plywood or OSB, a tape measure, a circular saw, roof ventilation, drip edge flashing, and underlayment.
• Start at the bottom of the roof and place the sheathing boards in rows.
• Work your way up the roof and fasten the sheathing to the roofing frame using roofing nails.
• Stagger the pieces to avoid long lines of joints.
• Install a drip edge for waterproofing.
• Secure the flashing along the edge of the roof and overlap sections to create a seal.

Plywood and OSB

Plywood and OSB are both wood panels made by compressing and gluing pieces of wood together. According to the International Association of Certified Home Inspectors, OSB and plywood share many strengths and performance characteristics, but differences in manufacturing processes contribute to each material having its own pros and cons.

OSB is more uniform and less expensive than plywood, costing about $700 less on a typical 2,400-square-foot house. However, OSB weighs more than plywood, which means it’s more difficult to install and puts more stress on the home’s structure. OSB also swells more when it comes into contact with water and takes longer to dry. This uplifts any materials that lie above OSB and makes decay more likely.

Underlayment

Between the covering and sheathing is the underlayment, which provides an extra layer of protection against water. Underlayment is typically made from asphalt-saturated felt or synthetic materials and covers the entire roof deck. This roofing layer is a vital component and prevents high winds from pushing rain into your home through the roof.

After you install your roof sheathing, install the roof’s underlayment.

1. Roll out the underlayment starting at the bottom of the roof all the way to the roof’s peak, overlapping each section as you work.
2. Peel off the paper backing and press firmly into place.
3. After you install the underlayment over the roof, roll out another layer over the roof’s overhang.

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Flashing, Ventilation, and Seals

Proper flashing, ventilation, and seals are necessary in the overall design of your roof to protect the roof’s life span and ensure it functions correctly.

Without proper roof ventilation, warm air and moisture can build in your home and lead to costly repairs, such as mold remediation. Roof ventilation allows air to circulate through your home, which is an essential part of every roof design. There are also plumbing vents that run from the plumbing fixture up through the roof and boots around the vents to waterproof pipe penetrations.

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Our Conclusion

Learning how to build a roof can save you thousands of dollars in labor costs, and you may be able to get the job done on your own timeline. However, even a slight misstep can result in potential damage to your roof and cost more in the long run. If you’re unsure of any part of the roofing process, you should hire a professional to finish the job.

Once you build your new roof, keep up with routine maintenance and inspections to extend your roof’s life span and avoid costly roof repair expenses. Regularly check your roof for leaks and inspect your gutters for signs of wear and tear.

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FAQ About How To Build a Roof

How long does it take to build a roof?

How long it takes to build a roof depends on the materials used. Roof replacement typically takes one to 12 days, depending on the roofing materials used, your home’s size, and the weather.

What tools do you need to build a roof?

You’ll need the following tools and materials to build a roof:

• Work gloves
• Caulking gun and caulk
• Chalk line
• Circular saw

Fall protection, such as body harnesses, lanyards, anchor points, roofing brackets, guardrails, safety nets, and safety tethers

• Framing square
• Hammer tacker
• Ladder
• Roofing hammer
• Roofing nail gun and air compressor
• Roofing nails
• Tape measure
• Tarps
• Tool belt
• Utility knife

Is building your own roof worth it?

Building a roof on your own can save you thousands of dollars, but there are safety risks involved, and some parts of installation require professional expertise. Additionally, if you don’t install your roof properly, you could end up paying more in repair expenses.

What are the steps in framing a roof?

Here are the steps in framing a roof:

• Trim and finish.
• Choose the roof style and design and determine whether you want to build rafters or use pre-fab trusses.
• Determine the desired roof pitch.
• Gather all tools and materials.
• Install roof trusses or rafters.
• Install the ridge beam, if applicable.
• Install roof sheathing.
• Install roof ventilation.
• Install flashing and underlayment.

Do I need a permit to build a new roof?

Yes, any structural work to your home requires a permit. Call your local building department to request a building permit for your homebuilding project.