Gable Roof: Defined, Compared to Hip Roofs, Design, Construction & Cost
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Here are gable roof basics for comparing this most popular roof type to others you’re considering for your building project.
GABLE ROOF DEFINED, OR, WHAT IS A GABLE ROOF?
A gable roof is one that forms an isosceles triangle of wall beneath the peak formed by the slope of the roof. The pitch or slope of the roof that forms a gable is typically at least 4/12 (4” vertical rise in elevation for every 12” of sloped horizontal run) and can be as steep as 20/12.
Home construction that is a simple rectangle will have two gables. Homes with more complex footprints will have three or more. Dormers extending from the roof may have gables too, based on their design.
The functional purpose of gable roofs is to facilitate the runoff of rain, so while found everywhere, they are especially useful in climates where heavy rains are common. Gable roofs with overhanging eaves catch wind, so homes in areas where hurricanes and high straight-line winds are possible either use a different style of roof or have gable roofs with flush eaves (not overhanging). In climates with heavy snowfall, a steep gable roof offsets the weight of the snow and allows the roof to shed it more easily than a flatter roof would.
Gable roof construction has a long history dating to Europe’s classical Greek and Gothic architectural styles.
GABLE ROOF VS HIP ROOF (OR BOTH)
Two popular roofing options are to terminate the roof in a gable end or in a hip end. Combining elements of the two is a third option.
Is a gable roof or a hip roof better for your purposes? Or a combination? This guide discusses each with features and pros and cons.
WHAT IS A GABLE ROOF END?
Gable roof ends remain the most common roof design. The roof terminates in a peak, so that the upper part of the house wall beneath it is an isosceles triangle.
Gable end variations: Gable ends can be modified to produce these variations:
- Box gable
If the gable has an overhang, the area from the peak to the base of the triangle can be enclosed with siding that is flush to the rakes, the boards that form the edge of the roof. The material used can be different than what is on the rest of the home’s exterior. For example, a wood-sided box above brick or stone provides visual contrast.
- Winged gable
When the peak of the roof is extended well beyond the end wall and the gable ends slant back toward the wall, the structure is called a wing, or winged gable. The wing provides awning-like shade to a gable window, but when winged gables are hit with high winds, the roofing can be torn off more easily.
WHAT IS A HIP ROOF END?
There is no gable on a hip roof. Instead, the peak triangle is replaced with a triangle of roofing that slopes down and away from the house. The hip typically has the same pitch as the rest of the roof, but might have less slope when extended to cover a porch or car port.
This roof has a small gable on the front dormer and a hip on the side.
Combination Hip/Gable Roofs
Your third option is to combine elements of both roof styles by roofing a portion of the gable end:
- Dutch gable/Dutch hip roof: This structure includes roofing that wraps around the gable end below the peak, leaving a smaller triangle of wall above it. The roofing connects to the roofing on the adjoining sides of the house. Though the definitions are fluid, if the design features more gable and less roof, it is a Dutch gable; when the end is mostly roofed to leave a small peak triangle, it is a Dutch hip.
- Clipped gable roof: In this design, a small hip covers the upper third to half of the peak triangle, clipping of its top, so to speak.
With your options defined, here are the strengths and weaknesses of each.
PROS AND CONS OF A GABLE ROOF
Advantages – This roof delivers a clean, classic look to any home. If you’d like to dress up your gable end, boxing it is an option or an appealing array of pediments, gable decorations and attractive bracing is available in wood and maintenance-free materials. Gables allow for cross ventilation for living space or for removing moisture and excess heat from an attic.
Finally, since the least amount of roofing is used is this design, and roofing is more expensive than siding, gable end roofs are the most affordable to build and to maintain over the years.
Disadvantages – There are a couple potential drawbacks to open gable roof ends. Some consider the look boring. Structurally, a gable end exposes the edges of roofing materials to rain and high winds unless the ends are capped.
Gables with roof overhangs catch hurricane winds and strong straight winds, so special bracing and additional fasteners must be added, retroactively in many cases, where these weather events are possible. The expense can be significant. Because of the wind susceptibility, winged gables should not be used in high-wind areas.
PROS AND CONS OF A HIP ROOF
Advantages – Hip roofs are stylish additions to any home, very impressive on a two-story or a ranch home with high walls or a vaulted ceiling. Roofs with hips, especially when there is no overhang, handle wind better than peaks. An extended hip makes a nice cover for a stoop or porch too.
Disadvantages – The cons of a hip roof start with the higher cost of construction, materials and maintenance. An attic beneath is more difficult and costly to vent. Finally, since the roof begins sloping downward to form the hip before it would end at a gable peak, the usable space beneath it is reduced.
The Best and Worst of Both
Clipped gable roofs and Dutch hip/gable roofs combine the pros and cons of gable and hip roofs in every respect. Both leave room for a gable vent, and a Dutch hip doesn’t reduce living space to the extent a full hip roof does. Construction and upkeep costs are higher for clipped gables and Dutch styles, and they can catch wind.
GABLE ROOF, HIP ROOF OR A COMBINATION?
If costs are a factor, then a gable roof is a clear choice. Apart from cost, most homeowners make their decision based on the appearance that each type of roof produces. Browse pictures of homes in the general style you prefer with the various roof options. If you are working with an architect, ask for separate renderings with the roof types you’re considering. Another option is to use a free online architectural CAD software like NCH DreamPlan to explore the look of various home designs.
GABLE ROOF DESIGNS & OPTIONS
Front gables facing the street are common when a narrow lot forces the construction of a home that is deeper than it is wide. Side gables are more common on wider homes, though many of those homes have dormer gables in front to allow for windows or to provide architectural distinction.
There are many variations on the basic gable that provide visual interest and/or affect the dimensions of the space immediately below the roof.
- Box gable
When the gable triangle is enclosed rather than open, the construction is known as a box gable.
- Cross gable
When a section of the house extends out from the main body of the house, its gable is known as a cross gable.
- Dutch gable
When the gable wall features a section of roof butting to it and sloping down from it, leaving a small triangle of wall above it, the form is a Dutch gable. The Dutch gable roofing might wrap around to connect to the rest of the roof structure.
A winged gable is formed by extending the ridge board at the peak of the roof well beyond the gable wall and then angling the roof down and back towards the gable wall. The overhanging roof of the gable, called a rake, is therefore wider at the peak than where it meets the eaves.
- Double and triple gables
These are complex roof designs in which one side of the home features two or three gables. The second and third gables either stand side-by-side the first or are smaller and built within the framework of a larger gable area.
- Hip/Gable combination
A hip roof is one in which the area that would form the gable is covered with roof sheathing and material. The ridge board doesn’t extend to the exterior wall, but stops at a point to produce the desired slope of the hip. A hip/gable combination is an architectural design in which part of the gable triangle is covered by a small hip.
Q: What is a clipped gable roof?
A: When the peak of the gable is covered by or overhung by a portion of roof, like a small hip, the construction is termed a clipped gable roof.
Q: What does a split gable refer to?
A: The term indicates a gable that is split vertically to form two separate roofs, one lower and with a shallower pitch than the other. A short vertical wall is formed between the two roofs.
Now that we’ve covered the basics, you might want to explore additional topics such as building a gable roof, deciding between a gable roof and a hip roof and determining gable roof cost and materials.
GABLE ROOF CONSTRUCTION
The steep learning curve for building trusses by hand to form a gale roof scares off most DIY homeowners. As this pro guide says, “If you are able to read a book of rafter tables, draw a right triangle, use a framing square or speed square, and use a circular saw then you can frame a gable roof.”
Those are big “ifs,” and if you have mastered the skills required to construct a roof system, then go for it. If not, but you still want to learn how to build a gable roof, you’ll need information and tutorials beyond the scope of this page. Add cross gables, a Dutch gable or other modification options, and the challenge of gable roof framing grows.
Consider this: Even most pro builders order engineered roof trusses from a truss company. First, truss companies employ craftsmen who are experts in reading drawings and getting the measurements, angles and cuts precisely correct for the roof’s slope, width and features. The trusses are built in a factory setting where accuracy is more easily controlled. Finally, because trusses are built more quickly in a factory than on a jobsite, the cost is significantly lower.
ORDERING TRUSSES TO BUILD A GABLE ROOF
If you have a blueprint or similar plans, then the truss company has the information for building trusses to frame your gable roof.
When there is no diagram, then the truss company will need this information to build your truss package:
- Roof pitch
- Home length, if rectangular, or section lengths, if an L-shaped or more complex home
- Dead load (weight of the roof deck and roofing materials) and live load (added weight of potential snow in that climate) requirements where you live will determine the distance between trusses (16” and 24” on center are common) and how many trusses are needed
- Width of the home or sections (the truss span)
- Whether the trusses will overhang the side walls to form eaves or be flush with the wall
- Whether you want a raised heel truss to accommodate additional insulation
- Bearing width based on the location of load-bearing walls determines how strong the trusses will have to be
- Complete specifications on dormers, hips, wings and other structural features of the roof
- Ceiling type such as flat or vaulted
ADDING A GABLE TO AN EXISTING ROOF
When building a home addition, the new section is often connected using a gable-style roof that adjoins the slope of the existing roof. The are the basic steps for adding a gable to an existing roof:
- Remove the siding from the home where the addition will attach
- Remove roofing material from the home where the addition roof will attach
- Frame the addition
- Attach a series of gradually shallower trusses, known as the fill, from the addition to the existing roof to accommodate the roof slope
- Add siding and roofing that gives the entire home uniform appearance
GABLE ROOF CALCULATOR
A gable roof calculator is a useful tool for determining how many trusses you need for your gable roof. Most roof calculators also give you total square feet of roofing, a figure used to order plywood and roofing shingles or other roofing material.
When using a calculator for homes that are more complex than a simple rectangle, calculate each section of the home separately because you’ll need a different truss set for each.
The inputs for gable roof calculators are wall length, wall width, slope/pitch, overhangs (if applicable) and spacing between trusses. Spacing is typically 24” on center, but the snow load requirements in your area, type of roofing you’ll use and whether the home has interior load-bearing walls might change that specification. Your local building code department has the requirements you need to follow for building a safe, code-compliant gable roof.
GABLE ROOF EXTRAS
These features are commonly found in gables:
Dressing up the gable peak with decorative trim that affix to the facia boosts visual interest. Wood is sometimes used, but most gable decorations, pediments, brackets, gable ornaments and gingerbread are made from maintenance-free materials such as vinyl or lightweight but strong polyurethane foam called fypon.
DECORATIVE SIDING IN GABLES
Siding the gable with a complementary material is an attractive design detail. Your options include shakes, shingles, boards and stone or brick veneer. All are available in low-maintenance fiber cement or no-maintenance vinyl panels.
Vents near the gable peak, along with ridge and soffit vents, promote the circulation of air that rids attics of moisture and excess heat that will otherwise cause a myriad of issues for the framing and roofing material. Gable vent design includes round, half-round, square, square with rounded top and triangular. The vents are usually louvered to keep rain out, and they might be screened against insects, birds and bats.
Further Reading: Ridge Vents vs Box Vents
GABLE END WINDOWS
If the area immediately below the roof is living space rather than an attic, then windows are essential. The entire gable can be a window or more traditional windows in frames can be installed. Even if the area is an attic, a fixed window may be installed for curb appeal, though it won’t replace a gable vent for ventilation. The many styles and shapes of gable window frames give you options to fit your home’s unique design and exterior materials.
Q: What is gable bracing?
A: Building codes in areas at risk for hurricane winds require gable end bracing to add strength. The bracing is formed by the installation of 2×4 braces nailed to the gable wall and the roof trusses. The bracing is often assisted by the installation of additional fasteners, metal straps that hold the trusses more securely or specialty connectors determined by the design of the roof structure. Many homes in hurricane country are being retrofitted with gable end bracing either voluntarily or by local codes to limit future damage. Consult your local building department about what is required where you live, and have a roofing contractor inspect your attic to see whether it complies.
Q: What are gable roof end wedge closures, caps and tiles?
These features prevent wind and wind-driven rain from getting under the edge of the roof deck and roofing material. They are most commonly used with tile, wood shake/shingle and metal roofing. Wedge closures fill the gap formed by overlapping tiles at the gable end. Caps and tiles extend above the roof edge to block exposure to the elements.
Those are the details for building a gable roof and customizing it for your home. Take your research to the next step with our detailed overview of the materials and cost of a gable roof.
GABLE ROOF COST
What does a gable roof cost? This quick guide shows you how to calculate all material quantities including trusses, sheathing and shingle and provides cost ranges for each.
THE COST OF GABLE ROOF TRUSSES
Determine the number of trusses you’ll need by diving roof length by 24” (standard) or 16” (for snow loads and heavy roofing material) and adding one end frame trust for each gable. Your local building department can tell you what truss spacing, 16” or 24”, is right for your home.
The truss length will be the width of the span it will cover. Add two feet for overhanging trusses. The steeper the trusses are, the more material they will contain and the higher the cost will be per linear foot.
The truss cost range will be:
- Standard truss cost: $4.15-$6.25 per linear foot
- End frame truss cost: $4.85-$7.50 per linear foot
Truss installation involves lifting the trusses by hand onto the roof or with the assistance of a crane.
- Crane rental: $400-$700 per day
- Truss installation: $60-$70 per truss
ROOF SHEATHING AND MATERIAL QUANTITIES
Here’s how to determine the quantities needed. There’s an example below.
Determining roof sheathing: These factors give you a ballpark estimation of your roof deck area based on roof pitch. Multiply the Factor by the number of square feet in your home’s footprint including the garage to determine the amount of roof sheathing required.
Determining roofing material: Once you’ve figured the square feet of roof deck, multiply that number by 1.05 for the roofing material total. The extra 5% accounts for trimming and waste.
Sheathing and roof material example: 2,000 square foot home and garage footprint with a 6/12 pitch roof:
- 2,000 x 1.12 = 2,240 square feet of sheathing
- 2,240 x 1.05 = 2,352 square feet of roofing material
If you prefer punching in numbers, here is a calculator for roofing area (decking) and roofing material.
ROOF SHEATHING AND MATERIAL COSTS
Sheathing material is sold in 4’x8’ sheets for 32 square feet per sheet. Divide the square feet of roof area by 32 to determine the number of sheets needed, and add two or three sheets for trimming and waste.
- Roof sheathing cost: $15.50-$20.00 per sheet / 48-63 cents per square foot
Shingles are sold in bundles containing approximately 33.3 square feet.
- Shingles cost: $20-$80 per bundle / $.60-$2.40 per square foot
Felt paper, starter shingles, flashing and ridge vents are accessories required to complete the roof.
- Roofing accessories cost: $28-$50 per square / 28-50 cents per square foot
The more complex the roof is, the higher the cost will be. Installation also costs more on homes with more than one level.
- Roofing installation cost: $150-$300 per square / $1.50-$3.00 per square foot
SUMMARY OF GABLE ROOF COSTS
In simplest terms, here are the costs to consider when budgeting for your roofing project.
Standard truss $4.15-$6.25 per linear foot
End frame truss $4.85-$7.50 per linear foot
Crane rental (optional) $400-$700
Truss installation $60-$70 per truss
Roof sheathing $.48-$.63 cents per square foot
Shingles $.60-$2.40 per square foot
Accessories $.28-$.50 per square foot
Roofing installation $1.50-$3.00 per square foot
Adding up the costs outlined here will give you an excellent idea of the gable roof estimates you’ll see when getting estimates from roofing contractors.