While there are many different types of roofing materials to choose from each is not created equal. Price, ease of installation and the length of time the roof will last can affect your decisions when choosing which is best for you.
Choosing the best material for your shed roof means exploring the qualities and drawbacks of each material, ease of installation of each, longevity, and the cost of each. These should be balanced against each other to find the best choice for you.
For instance, if you are not handy with tools or aren’t able to get onto a roof, you may choose a material that has lesser installation costs. If you live in a hot, sunny climate, asphalt shingles may not be a good choice.
What is the Best Material for a Shed Roof?
The best material for a shed roof depends on your needs and your budget. You want to get the most sturdy, weatherproof, low maintenance, damage-proof material you can afford. You also want one that either you can install yourself or does not break the bank to pay for installation. Since about 80% of roofs use asphalt shingles, the popularity of these tells you that they must do the job without costing too much and should be seriously considered.
Which Roofing Material is the Most Durable?
Slate roofing has the longest potential lifespan of roofing materials, lasting 50 to 100 years. It is also one of the most expensive materials. Besides the actual cost of the material, the actual roof structure must be built to support the extra weight, or extra support added to an existing structure.
The downsides are that the tiles can fly off with high winds and can cause injury and damage. Also, regular inspections are needed, and damaged or missing shingles replaced promptly.
Clay or concrete tiles also have long lifespans. Concrete tiles last 40 to 75 years, while clay tiles can last 50 to 100 years. These tiles have the same drawbacks as slate, requiring extra support and roof bracing for the extra weight and the tendency for the tiles to be affected by high winds. These too can injury people when they fall or fly off.
Metal roofing can last for 50 years or more, depending on the type and installation. Ribbed metal panels can last for 40 years. For more information on metal roofing and installation read my article How to Install Galvanized Metal Roofing On a Shed.
Asphalt shingles are the most commonly used roofing material, especially on sheds. The common three-tab shingles usually last 10 to 20 years. There are architectural shingles that are thicker. These last 15 to 25 years. The one thing that will lessen the lifespan of these shingles is a lot of strong sunlight, which will eventually cause the asphalt to age and crack prematurely.
What is the Cheapest Roofing Material for a Shed?
This question is a bit tricky. The cheapest roofing materials for a shed are roofing felt or mineral felt. These make good underlayment’s for other materials, but as roofing materials themselves, they aren’t very good.
The problem is that both can get damaged fairly easily with falling tree debris and require replacement rather often, sometimes only lasting a year or two, thus negating any cost savings up front. Besides the replacement cost, there is the problem of having roofing projects on your to-do list over and over again.
The roofing material that will probably give you the most bang for your buck, in the long run, is the traditional asphalt shingle. It will protect your roof for decades, is easy to install and maintain, and any shingle replacements are fairly easy to accomplish.
Should I Use Underlay on Shed Roof?
Underlayment acts as a moisture barrier, keeping water from seeping through to your roof sheathing and eventually into your shed. Moisture can slowly seep through from a small leak, enabling mold or rot to form in your sheathing or roof supports before you even notice it. It is especially important if you use Oriented Strand Board or OSB for your sheathing, as this material is sensitive to moisture and prone to swell if it gets damp.
Some grades are treated to withstand moisture, especially if any cut sides are treated after the cuts are made, but none of it is waterproof, and will all be affected eventually if moisture is an ongoing problem. The roofing felt will protect the joints and cut edges.
The underlayment also acts as some extra insulation and soundproofing. The roofing felt makes a smooth path for any moisture that might get under a shingle to just roll on down off the roof. Roofing felt is not waterproof, but it does have repellent qualities and will help wick moisture away with small leaks.
Should I Use OSB or Plywood for Roof Sheathing?
This is something that will have to be balanced. Both have pros and cons, and prices for materials fluctuate with time and the local marketplace. Both are rated the same as to temporary vulnerability to weather and they are used with the same installation methods.
OSB is formed from wood usually raised on tree farms using small, fast-growing trees. This is a plus for ecologically minded consumers. It can be bought in longer sheets than plywood, meaning fewer seams when building. OSB is denser than plywood. OSB made with 50 layers can be compressed into the same width as plywood containing five to seven layers. OSB also doesn’t have the problem of weak spots associated with knotholes.
The downsides include the fact that it is heavier than plywood, thus a little harder to handle. The main problem is that when OSB gets wet, it takes longer to get wet but also longer to dry out. When used as roofing sheathing, this means it can degrade faster when a small leak affects it and is not discovered and repaired promptly.
Damp OSB first tends to swell along the edges. Unfortunately, once the board dries, the shape does not go back to normal, leading to permanently raised ridges under your roofing material. This can be helped by using a waterproofing treatment for OSB to treat edges that have been cut.
Manufacturers keep working on ways to solve the moisture problems, but still, some construction-related associations recommend plywood for subflooring because of the risk of OSB’s edge swelling problems.
Plywood is also affected by moisture but in a different way. When plywood gets wet, it also swells, but the swell is consistent over the whole sheet. It dries more quickly than does OSB, and once it does, the swelling goes back to normal size. This means that any swelling will not permanently affect your roof.
Plywood also is stiffer than equivalent thicknesses of OSB, meaning that you don’t have to get plywood as thick as OSB in order to have the same structural strength. Plywood is usually a bit pricier than OSB, however. When choosing one or the other, taking the likelihood of moisture problems with your weather conditions should be a consideration. For more information on plywood read my article What’s the Correct Direction for Installing Plywood?
Should I Remove Old Material When Re-Roofing My Shed?
You may be able to leave the old roofing on depending on what kind of roofing it is and what condition it is in. The problem is that if the old roof is good enough to leave on, you wouldn’t have to re-roof your shed. Curled up and damaged shingles can cause problems when installing new shingles over them. They can cause your new roofing to be lumpy.
A smooth surface makes it easier for rainwater to slide off. In addition, damaged shingles under your old ones may cause small dips in the surface which can hold water. Some municipalities have limits as to how many layers you can have on your roof. While you may be able to install new shingles over the old ones, this can be done only one time without problems from the authorities.
Even one extra layer of shingles also adds quite a bit of weight to your roof, up to 240 lbs. per square. Your rafters, trusses and sheathing don’t need that extra weight. One great benefit of tearing off the old roofing is that it enables you to spot problems you weren’t aware of. You may have a small leak that is situated over a truss joint that didn’t drip down to a place where it was visible to you, but which can enable mold and rot nonetheless.
You can discover that a piece of sheathing may need to be replaced or small tears in the roofing felt that you didn’t know about. If you tear off your old roofing and discover one of these problems, you’ll be glad you did remove the old roofing instead of covering it up even more and leaving the problem to get worse.
How Much Does It Cost to Roof a Shed?
Prices differ from one area of the country to another, even from one city to another or from city to rural area. They also differ according to demand at certain times, such as being more expensive in the spring when building really ramps up. That being said, there can be some averages investigated and considered when planning a shed roof.
Roofing felt has a starting cost on average of $30 per 100 square feet, also known as a square. This depends on the grade of the paper. While using it as the actual roofing material is less expensive than other choices and it is easy to install, it doesn’t hold up well to weather and falling debris. The frequent replacement needed probably will negate the initial savings in the long run.
Asphalt or three-tab shingles are the most popular choice for roofing for homes as well as sheds. They last up to 20 years and even longer. They are fairly easy to install. While they are not the most attractive roofing choice they do come in a wide variety of colors and styles and allow you to have your shed roof match your house roof without much effort. These shingles start at around $50 per square.
Architectural shingles are also made of asphalt but they are thicker and last longer than the usual three-tab shingles. Some are made to look like more expensive products such as cedar shingles or shakes. Warranties vary with the product, but the average is 30 years. The price starts at about $60 to $80 per square.
Fiberglass shingles are a choice that is similar to asphalt shingles in appearance and installation methods. They are made of a woven fiberglass mat, which is covered with an asphalt coating. The coating is waterproof and is topped with granules designed to protect the shingles from UV rays.
Since the fiberglass base is strong, less asphalt is needed to make the shingles strong and durable, and this fact makes them lighter weight than traditional asphalt shingles. They are also considered to be a more environmentally friendly product. They are vulnerable to very cold climates and prolonged low temperatures may cause damage. They also are more expensive than traditional asphalt shingles, costing $100 to $300 per square.
Wood shakes have an attractive natural look. Your roof won’t look like any other shake roof due to variations in the wood color and grain. As they age, they take on an attractive, silvery appearance. They are very high maintenance, however, and must be regularly inspected. Moss and algae tend to make a home on these shingles in shaded areas, which can lead to moisture problems.
Falling tree debris or other windblown debris hitting the shakes may split them, causing them to need replacement. They also are subject to the same insect damage as any other wood product. Shakes can run from $100 to $200 per square.
Metal roofing is usually made of steel but can be made of aluminum. It is very durable and strong, is not subject to insect damage, and is great at repelling moisture when installed correctly. It also does not require much maintenance and is very rot resistant. It does require regular inspection for deep scratches and gouges that go into the metal and may cause rust.
Fasteners installed incorrectly or with the wrong washers may allow leaks to form around them. Any damage such as dents requires replacing the whole panel. Both aluminum and steel metal roofing runs from $100 to $300 per square. For more information on the types of metal roofing read my article What’s the Best Metal Roofing for a Shed?
Conclusion
As stated before, choosing a roofing material means balancing several factors and finding out what works best for you. Your climate plays a big part in the decision as does your budget and the possibility of installing it yourself. A good start would be to visit a supplier and explore the options available. Ask a lot of questions and you’ll soon have the information you need to make a decision.