Estimating Roof Pitch & Determining Suitable Roof Types – DIY Guide

So it’s time for a new roof, or perhaps you are planning a new home construction project and are considering what your new roof should look like. Surely, you have heard about all the exciting new roofing materials available today and are eager to get started.

roof pitch expressed in degrees

However, before you can make the call on what to put on the roof, you need to know the pitch or slope of the roof! πŸ˜‰

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Why It’s Important

The roof pitch is necessary for two things – one, estimating the amount of material to be ordered for the job and two, knowing what materials are suited for the roof. But, again we are jumping ahead of ourselves. Before we get started with all that we need to find out the pitch of a roof.

What is a roof pitch?

roof-slopes

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Pitch, angle, incline, slope – they all can be used to refer to the steepness of a roof. In the roofing trade the go-to term is “pitch” and it is expressed in terms of “12 inches.” So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally.

If a roof increases in height by four inches for every foot of horizontal run, it is considered to have a “4-in-12 pitch” or just a “4 pitch.” Talk in terms of pitches and you will always be understood in the roofing universe. πŸ˜‰

Measuring a roof pitch

Ideally you will have safe access to your roof from inside the building. If not you will need to make your measurement from on top of the roof itself or at the edge of the roof with a ladder.

The tools required will be a contractor’s level at least 24 inches long and a tape measure.

Place the butt end of the level against the edge of the roof and extend it into the air, balancing it until it becomes level. At that point measure down from the exposed butt end back to the roof surface.

Divide the results by the number of 12-inch segments in your level. For example, if you used a 24-inch level and your measurement was 12 inches the pitch in your roof is 6-in-12.

You can also estimate a roof pitch by eyeballing it from the ground from the gable side with a level and ruler.

If for some reason you have absolutely no access to basic tools you can guesstimate the pitch of a roof by knowing that clapboards generally present four inches of exposed face and a dollar bill is six inches.

So you can count the clapboards from the low end of the roof to the peak and use a dollar bill to figure out your stride and pace off the the size of the building. Then make your mathematical calculations.

Using roof pitch to order materials

Once you know the width and length of the space to be covered you can apply the roof pitch to determine exactly how much roofing material to order without leaving yourself short or wasting money with overages. To do that requires basic geometry but fret not, you can just refer to tables that are standard in the industry:

Multipliers used for estimating roof area based on slope:

0 pitch – 1.00X the roof area. Since this is a flat roof or nearly flat roof. You can go by the measurements taken by walking the roof.

1 pitch – 1.01
2 pitch – 1.02
3 pitch – 1.03
4 pitch – 1.05
5 pitch – 1.085
6 pitch – 1.12
7 pitch – 1.16
8 pitch – 1.21
9 pitch – 1.25
10 pitch – 1.31
11 pitch – 1.36
12 pitch – 1.42

Roof Pitch Expressed in Degrees:

roof pitch expressed in degrees

12 pitch = 45 degrees
11 pitch = 42.5 degrees
10 pitch = 40 degrees
9 pitch = 37 degrees
8 pitch = 33.75 degrees
7 pitch = 30.5 degrees
6 pitch = 26.5 degrees
5 pitch = 22.5 degrees
4 pitch = 18.5 degrees
3 pitch = 14 degrees
2 pitch = 9.5 degrees
1 pitch = 4.5 degrees
0 pitch = 0 degrees

How Roof Pitch Manifests Itself in Various Roof Types

Roof Types Diagram

Roof shapes have evolved through history in different regions of the world from flat to steeply pitched. Here are some of the common shapes that top roofs today:

Flat roofs are common with industrial buildings boasting wide roof spans and are also popular in dry climates for houses where there is no need for the roof to help disperse rain and snow. Even in these arid regions so-called “flat roofs” are still installed with a slight pitch to keep water from pooling on top of the structure.

A mono-pitched roof runs from a taller wall to a wall of lesser height to produce a slope. This is often a configuration seen on simple shed buildings.

Saw-tooth roofs can often be seen on old-school factories that were constructed with a series of mono-pitched roofs that are used to allow sunlight to filter down to the shop floor.

Pent roof is a collection of low mono-pitched roofs often seen on residential terraces.

A gable roof is a traditional triangle-shaped roof that can range from a medium pitch to sharp angled roofs.

A-frame roof is the sharpest gable-style roof resembling the shape of the letter-A. It is a traditional roof shape employed everywhere from tropical huts to Nordic ski chalets.

Asian-style roofs: The influences of Asian architecture have infiltrated American shores in recent years. Gracefully sloping roofs are often of medium pitch which emphasize the horizontal spread of the buildings.

Hipped roofs: These distinctive roofs with overhanging eaves feature four medium pitched sides and are characteristic of Dutch architecture and help disperse snow loads in northern climates. Hipped roofs are often used in complex roof formations with the β€œhips” facing different directions.

Saltbox roofs: The workhorse of Colonial America, the familiar saltbox is a building that features a long, pitched roof on one side, similar to the lid on a salt storage box. Their attractiveness traces to the desire to make a two-story building function as a one-story building to reduce the tax bill. The large expanse of such a roof will cause greater expense to cover.

A mansard roof, in opposition to a salt box, offers the utility of a full half-room on the upper floor rather than an attic. It features tow pitches, one a shallow pitch atop a steeper slope.

Pyramidal roofs: Sometimes seen on square buildings, a tented or pyramidal roof, feature four slopes rising to a peak. These are often steeply pitched roofs.

Gambrel roofs: Popular with barns and other structures that create additional interior room, these stepped roofs feature a short steep, non-walkable slope before rising more gently to a ridge peak.

Clerestory roofs: Another popular form for factories requiring light infiltration, the clerestory features long, low-pitched roofs before the building rises to a traditional gabled section atop the structure.

Conical roofs: A staple of Queen Anne Victorian architecture these conical towers were topped with dunce-cap roofs that are too steep to be walked on.

Arched roofs: Seen on utility structures there are several types of medium-pitched roofs that feature curves from gentle arches to bows and barrels.

Circular roofs: These full arched roofs can be anything from domes to decorative Byzantine-inspired onion domes. Domed roofs can be low-pitched or fully circular.

Pros and cons of various roof slopes

Low pitch roofs are easier to install and safer to walk around to complete repairs and maintenance. This is fortunate since flat roofs are somewhat more prone to leaks and require frequent inspections.

Low-pitch roofs are seldom used in regions of severe weather due to the stress of snow accumulation on roofs of structures.

Flat roofs can be significantly cheaper to install than a pitched roof, but they will often require more maintenance. Flat roofs are popular in regions of sparse rainfall and are favored by modern architects in contemporary designs.

Medium-pitched roofs come in a variety of styles and provide help with dispersing snow and rainfall while still being able to be inspected and repaired by the average homeowner by walking around the surface.

High-pitch, non-walkable roofs are dynamic and present an exciting appearance, but they are more expensive to install, and repairs will be left to roofing contractors with all the necessary safety equipment.


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2020 Standing Seam Metal Roof Details: Cost, Colors, and Pros & Cons

Standing seam is a descriptive industry term for vertical sheet metal panels. It’s one of the most popular metal roofing styles for homes, thanks to its beauty, durability, longevity, simplicity, versatility, energy efficiency, and its remarkably clean, bold looks.

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If you like the modern style of raised metal seams and clean lines, then consider installing this system on your home. A standing seam metal roof will not only compliment your home, but it will also give it that contemporary look and feel, along with its unmatched durability, longevity, and energy efficiency. πŸ˜‰

Standing Seam Metal Panels in a Nutshell

Standing seam is a high-end upgrade and an undisputed step up in quality and longevity from the classic corrugated and ribbed style metal roofs. Unlike its predecessor, corrugated steel roofing, which is still being widely used today for many commercial, industrial, and even some residential projects, standing seam has an improved design featuring concealed fasteners.

The ingenious design of standing seam metal roof featuring its characteristic raised seams, with no exposed screws in the roof, helps minimize the chance of a roof leak down the road.

Standing seam roof on a two story house

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Standing Seam vs. Corrugated Metal

Standing seam roofs are generally made from thicker grades of steel than corrugated steel roofs. While many corrugated steel roofs are made using the thinner 29 gauge steel, a minimum of 26 gauge G-90 galvanized steel or more commonly Galvalume steel (better) is used for manufacturing of standing seam metal panels.

A 24 and 22 gauge steel can also be used for residential and commercial styles including architectural (requiring a roof deck) and structural (requiring a suitable roof frame only) profiles.

A mid-panel stiffening technique is sometimes employed by the sheet metal fabricators, suppliers and manufacturers for a 16 inch and wider standing seam panels in order to prevent “oil canning” of the panels.

A metal coil from which standing seam panels are manufactured is usually factory painted with a high-end Kynar 500 paint finish. — this is unlike its close cousins corrugated and ribbed metal roofs (featuring exposed fasteners) that are often painted with cheaper, acrylic paints.


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Top 20 Roof Types and Pros & Cons – Roof Styles, Design & Architecture

It’s disappointing, but understandable, that more people don’t consider themselves β€œroof connoisseurs.” After all, most homeowners take their roofs for granted, as Bob Dylan put it, β€œshelter from the storm.” Oh, but accounting for only a mere 3% of the total house construction cost, a roof is so much more than that! πŸ˜‰

Roof Types Diagram

Aside from material selection, what really gives your roof personality is its design and construction; how the peaks and valleys merge together. Some people might not be aware they had multiple choices regarding roof design, but here are 20 of the most popular roof styles and their associated pros and cons.

Flat

flat-roof

Most flat roofs are not really 100% flat, but rather they are low-sloped roofs that appear flat, but have a little bit of a slope to allow for the run-off of rainwater. Flat roofs are commonly found in modern architecture style homes, commercial buildings, or home additions such as a sunroom.

As the name implies, a truly flat roof would have no pitch, which could lead to the obvious problem of rainwater pooling up and creating a stagnant spa area for mosquitoes, bacteria, mold, etc.

The rainwater problem can be solved by centrally-located drains, scuppers, and gutters to evacuate the water. Asphalt shingles and other traditional roofing materials are not viable options for low-slope roofs. Low-slope roofs are instead covered either by EPDM rubber, single-ply membranes, and multi-ply membranes, or a tar/asphalt coating that provides water protection.

PVC and TPO roofs are also viable options to explore. – They offer better longevity and durability compared to EPDM rubber roofs.

Gable

gable roof

The term ‘gable’ refers to the triangular shape that is formed when the two pitched areas of your roof meet. It makes sense then that a gable style roof is basically one side up and the other side down similar to the roof on a traditional dog house.

Did you know? Roofing contractors love gable roofs, because gable shape entails covering only two flat surfaces without any hips or valleys, which means that virtually any type of roofing material can be used.

The gable design is available in almost any type of roof pitch, from low-slope ranch style homes to steep A-frames.

One of the only major problems with a gable roof is that they hang over creating eaves which are ripe for peeling off completely under strong winds.

Hipped

hip and dormer roof

One of the biggest problems with the gable roof style is that the two ends of the two house will have no shade or cover because there are only two roofing surfaces. A hipped roof is the style of a roof shape that fixes such a problem. A hip roof is defined as ‘when all sides slope downwards towards the walls’.

Hipped roofs usually have four sides – two with triangular shapes and two with trapezoids. One of the difficulties with a hipped roof is matching materials between the sides and ends. They do perform better in high wind areas however, especially the steeper the pitch.

Gablet (Dutch gable)

A casserole of roofs that solves the individual problems created in both the gabled and hipped design is the gablet (UK) or Dutch gable (North America) design.

A gablet basically puts a gabled roof on top of a hipped roof. The result is easier access to the lower portion (hipped) of the roof with the added benefits of natural light and attic or bedroom space (gable). Most types of materials such as asphalt shingles and metal roofing can be used in a Dutch gable roof and in fact using variations in colors or types, actually adds a nice contrast.

Jerkinhead

The jerkinhead design typically features mostly gable with a little bit of hipped influx mixed in. Gable roofs that are clipped into a short hipped design on the ends are structurally superior to wind uplift.

This design is frequently seen on the second story of a house where the clipped hip doesn’t disrupt the view from a dormer window.

Saltbox

A saltbox-style roof is one that’s popular in New England and other Northeaster states. The asymmetrical design is trademarked by the front of the home having 2 stories compared to one story in the back.

The look resembles a profile view of the old salt boxes which utilized that design so it was easier to pour.

The long protrusion of the rear roof portion extending almost to the ground makes it great for rainwater to disperse from.

One of the cons includes rooms on the backside of the house having slanted ceilings, limiting tall people to use essentially half the house. The saltbox does provide more wind resistance than a standard gable house though – perfect if you can get around the unique looks.

Catslide

A catslide is very similar to a saltbox style roof except that they are often only used in portions of the back roof or on home additions. Catslides extend beyond the eaves of a building, creating more depth at the cost of height. A catslide might be used as an extension into a mudroom/entrance or a transition into a three-seasons/sun room.

Dormer

Gable Roof Dormer

A dormer isn’t necessarily an independent roof type, but more of an addition to an existent roofing style. A dormer is a window and a roof (gabled, hipped, flat, among others) that protrudes from the existing slope of a roof. Like some contractor’s tool belts a dormer can either be functional or just for show.

A functional dormer creates usable space out of the roof of a building, adding natural light and headroom. A false dormer is blocked off from the interior and is only used to boost curb appeal from the exterior. Dormers are usually, but not always, roofed in the same material as the house. To many roofing contractors they are a nuisance and an extra spot where a leak could arise, but for homeowners they serve as a priceless reading nook or way to get some morning sunshine. πŸ™‚

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