What Is A Flat Roof
A roof needs a drainage system. Homes in rainy climates require drainage, so flat roofs arent popular. Most flat roofs have slopes and arent flat.
Most flat roofs are set at ten-degree angles or less. They look flat while and water a place to run. Drainage should be your number one concern when building a flat roof.
Its Economic And Efficient
Flat roofs can be expensive up front, nearly 80 cents per foot if youre using some of the higher end materials, But a person will quickly find that their roofs will last almost 30 years average with minimal maintenance. For those willing to increase their budgets and purchase some of the higher end roofing materials, this lifespan can become even longer. Additionally, many contractors will charge much less for labor on flat roofs due to the simplicity of installation.
Hot Roof System: Recommended By Experts
As mentioned earlier, experts do not recommend insulating a flat roof from the inside anymore. Instead, the current trend is to insulate using a hot roof system, otherwise known as a warm flat roof. This type of insulation does not lead to condensation. Instead, the insulation material is put on top of the roof structure.
A warm roof deck usually uses at least 100mm of rigid insulation placed on top of the roof joists or the vapor control layer. Then, another layer of a waterproofing system is applied above the insulation material. No ventilation is required for a hot roof system.
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Flat Roof Space Is Usable Space
Unlike a steeply pitched roof, most of the square footage of a flat roof is available for use. This offers the option to add a unique application such as a rooftop patio, garden or green roof. Solar panels also are popular among homeowners and are much easier to install and hide from view on a flat roof.
Any of these applications will require certain design considerations . Special permits may be required from the local building authority, but these efforts may result in an entirely new feature to enjoy on your home.
Different Types Of Flat Roof Material Options
Kelly Bacon is a licensed general contractor with over 40 years of experience in construction, home building and remodeling, and commercial building. He is a member of The Spruce Home Improvement Review Board.
The flexibility of a flat roof offers certain benefits, but flat roofs do have a bit of a reputation for leaks and repairs. The good news is that there are material options for your flat roof beyond traditional hot-mopped, built-up roofing that will increase the reliability of the flat roof.
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How Long Does A Flat Roof Last
A flat roof will normally last 20-25 years if the roof was built properly along with regularly scheduled maintenance.
If your flat roof leak repair are the result of age and material break down, it typically doesnt make sense to repair it, but its best to determine what type of roof you have and how long your roof lasts.
Usually these kinds of leaks start to show up around the 12 or 15 year mark on a well-made roof, so if you are experiencing leaks around this time it is perhaps best to look into the costs of replacing it altogether.
Whats more, if the initial installation wasnt performed properly, you may need to replace the roof sooner. Keep in mind that small leaks can be easily repaired, but large or multiple leaks may make replacing the roof entirely the best option.
Install Additional Drains To Redirect Water
In some areas with high precipitation, the flat roof may not have enough drains for the amount of water pooling on the roof. Installing additional drains will help to redirect the water and get it off the roof. Another option is to widen the drains that are already on the roof so that more water can flow through them.
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Can I Install A Parapet On A Flat Roof
A flat roof by design will have a parapet. They protect your home from wind, rain, and hurricanes. Parapets also prevent your home from collapsing.
If your flat roof doesnt have a parapet, you can install Canales, otherwise known as roof scuppers. Canales are drain spouts that protect your roof from water build-up.
The Disadvantages Of Flat Roofing
With the good comes the bad, and it is important to learn the cons of a roofing system so you can figure out if it is right for your home. Here are the disadvantages of choosing a flat roof for your home.
- Lack of Drainage: The biggest disadvantage of a flat roof is the lack of drainage, and this is why it is important to check your roof regularly. If you do not inspect it regularly, your drains may become clogged with snow and water. You want to clean out the drains as needed and be sure to use a waterproof seal regularly to prevent leaks. Remember, there are no slopes for the water or snow to slide down.
- Debris and Dirt Can Build Up: Snow and water are not the only things that can cause problems on a flat roof. Leaves, twigs, dirt and other debris can also clog up the drain, and this leads to snow and water not draining properly. You can avoid a clogged drain by regularly inspecting and cleaning the dirt and debris off your roof.
- Limited Roofing Materials: The majority of flat roofs use rolled roofing materials, which include TPO, EPDM, rubber, and bitumen. The materials are inexpensive but only last from ten to 15 years. There are alternatives, such as using rubber shingles with rolled rubber roofing, but they are more expensive and it is unknown how long the materials will last.
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Ponding Water On A Flat Roof: What To Do
Commercial property owners and building managers face many challenges in protecting a real estate investment. When the building has a flat roof, there are additional problems such as ponding water. This is usually due to poor drainage systems which can cause long-term roof damage. However, with proper roof maintenance, you can keep the building in good working condition, prevent costly repairs, and protect your investment.
How To Repair A Flat Roof: What To Look For And What To Avoid
Image source: Royal Roofing
If you have a flat or low-slope roof, you’re probably familiar with EPDM or TPO rubber. While these materials may be weatherproof and can last up to 50 years, they can also stretch and degrade over time, causing leaks. EPDM is among the most common flat roof options for residential and commercial roofing, and it is possible to fix yourself. But if your roof has TPO or another rubber material like PVC or modified butamin, we recommend hiring a professional to repair the roof. In this article, we’ll discuss what to look for, common mistakes to avoid, and how to repair your flat roof if you’re able to do it yourself.
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Examining Flat Roof Myths What Are The Drawbacks
Flat roofs are hard to replace
Some observers suggest its harder to replace a flat roof than a traditional pitched shingle roof because of the labor required to remove its layers . But now, flat roofs often are constructed with fewer layers because of improved waterproofing technology. This could mean flat roofs may not raise the same red flags they used to among prospective homeowners who may want to replace or remodel the roof once they move in.
Prone to water damage or leakage
Many of the potential problems a flat roof may attract such as water pooling, leakage and resulting rot or damage are due to poor installation or poor maintenance. Pay careful attention to the roof at the construction phase and throughout its lifecycle to help prevent these problems in the first place.
What Can You Do With A Flat Roof
There are many different types of roofs that you will see across a variety of house and building styles from traditional thatched roofs and iconic peaked roofs to flat roofs found on utility buildings and occasionally building extensions. If youve moved into a new property or have been wondering how to add additional space to your property and have a flat roof, this guide is for you!
Below weve detailed the options you have for making efficient use of flat roofs and the sort of work that will be needed to make it durable and ensure it lasts without incurring any further repair or construction costs
Diy Flat Roofing Repair
A word to the wise you should always respect heights as well as ladders, so proceed with these DIY flat roofing repair tops with extreme caution.
Use a ladder thats well made and in good shape that you know can hold your weight, have another strong adult help you out by holding the ladder steady, and understand your limitations if the roof that you need to repair is icy or otherwise exceptionally slippery, practice even more precautions or call a professional with the proper equipment.
While the choice of repair methods depends on the type of roof that you have, rubber roof patches, rubber roofing materials, and roofing tar may all be involved.
Keep in mind that if you happen to have a leak in your PVC or TPO roof youll want to work with a company that specializes in this type of work specifically.
Things like a leaky seam, holes or rips caused by a fallen tree branch or similar debris, accidental punctures, or other issues with your PVC or TPO roof call for a qualified specialist equipped with all the necessary tools and supplies.
They should have access to a roll of appropriate membrane and a heat air gun.
Seeking out a company that specializes in PVC or TPO roof repair is your best option in this regard.
Heres a quick video on a flat roofing repair.
Begin By Identifying A Flat Roof Leak
Before you can start to try and repair a flat roof leak, youre going to need to identify the presence of one. You should always be on the lookout for any signs of a flat roof leak.
In some instances, it might be very easy to spot a flat roof leak. Youll have water dripping down from your ceiling on the inside of your building.
But in other cases, you might have a flat roof leak behind a wall or in another area that will be difficult to find. For this reason, you should keep your eyes peeled for any indication that you might have a flat roof leak on your hands.
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What Do I Need To Know Before Installing
In order to install a flat roof, you will need to have proper drainage in place. This means that your home must be designed specifically for a flat roof. You should also check with your local building codes to ensure that you are following all the necessary regulations.
It is important to hire an experienced contractor who has installed flat roofs before. Your contractor should also be a member of the Roofing Contractors Association, which ensures that they have experience and insurance.
Youll also need to install the correct insulation, which may include: rigid foam, board spray foam, wool batting, mineral wool, fiberglass, cellulose, loose-fill insulation, Icynene Spray Foam.
Evaluate For Damages And Repairs
After taking off your old roof, the next thing youll have to do is to evaluate your roof for any damages. If theres an issue with standing water, remove the entire roofing in that area, including its rotten woods. But if the wood is okay, use roofing tar to build up that area before applying your new roof material.
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How Long Do Flat Roofs Last
Flat roofs demand more maintenance and may be more prone to leaks. This may not be an issue for commercial building owners whose properties are subject to regular inspection. Homeowners , however, usually arent qualified in doing their own inspections and maintenance.
Adam Lewellen, sales manager at Long Roofing, notes that a well-made low slope roof is designed to last for the long haul. Inadequate repairs, however, and bad weather can hinder performance.
Most homeowners do not do the maintenance or replace their flat roofs on time, because they cant see them from the ground, Adam says.
Typically, by the time roofers are called, it has been 20 or 30 years and a lot of water damage has already occurred from premature failure or other type of catastrophic event.
What Is Considered A Low Slope Or Flat Roof
Roof pitch is the steepness of your roof or certain roof facets. Roof pitch is a ratio calculated by the number of inches or feet it rises vertically for every 12 inches or feet it extends horizontally.
For example, a roof with a 6/12 pitch will be 6 inches up for every 12 inches out. With that in mind, a roof is considered low slope when the roofs pitch is below a 2:12.
This means your roof is low slope if its pitch is less than 2 vertical units up for every 12 horizontal units out. It should be pretty obvious if your roof or a roof facet is low slope.
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The 3 Most Common Materials Used For Flat Roof Construction
There are several methods and materials for the design of the exterior surface of a warm or cold flat roof.
Material 1: Hot tar and gravel
Also known as the built-up roof , this type of flat roof features three or more layers of waterproof material, mixed in an alternating fashion with hot tar and a layer of smooth stone-like gravel.
As you might imagine, this is the cheapest version possible and good for covering a shed.
Material 2: Modified bitumen
This involves a single-ply rolled roof that creates a protective layer against ice and water. It can be made stronger with a mineral-based surface. To guarantee the material stays secure, most of these materials come as peel-and-stick systems that are easy to apply.
Material 3: Rubber membrane
Also known as EPDM , this is natural rubber the kind you might find on a car tire or an inner tube. Its durable, and can be fastened to the roof with fasteners and glue. This is probably one of the easiest versions for a DIY project.
Thermoplastic Membrane Flat Roof
This type of roofing is a single-ply layer of material fixed to the roof with screws and plates. Typically, it will be white or gray but it can also come in other colors. Theyre praised for their high-temperature tolerance and durability. There are two types of thermoplastic membrane roofing: polyvinyl chloride or thermoplastic olefin .
PVC is the third most-produced synthetic plastic polymer. As far as roofing goes, its relatively easy to install due to its flexibility. Its also the sturdiest of the two thermoplastic membrane roofing variations. They can usually last up to 20 years.
TPO is considered a more eco-friendly variation of the thermoplastic membrane roof. Once it comes time to replace the sheeting, you can recycle the old material. Some perks of this roofing material include UV absorption and flame resistance. TPO roofing can last anywhere from 15 – 20 years.
Overall, thermoplastic membrane roofs remain a popular option due to their relatively low cost, energy efficiency, and durability.
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Reduce Your Energy Bills
If you are looking for something a little less work intensive than a swimming pool orroof garden, you might want to consider some solar panels. Solar energy foryour home will cut down electricity bills, and help improve your environmentalfriendliness. The key to solar panel installation is ensuring the pieces areadded in the most effective space, and at the right angle. You will need toconsult an expert to get this correct, and they will need to be installed by aqualified and certified electrician.
Causes Of Flat Roof Leaks
Your flat roof can leak due to a variety of factors, including old age. If your roof is old, some areas may have deteriorated and will likely fail, allowing rainwater to infiltrate your building. In most cases, flat roofs leak around vents and plumbing stacks or at the edge of the roof.
Other common causes of leaks on flat roofs include:
- Ponding water When water remains on your roof for more than 48 hours after precipitation, it can lead to damaging leaks.
- Damaged Membrane If your flat roof is made of a single-ply membrane, it can be susceptible to damage due to ponding water or roof traffic. A compromised membrane allows water to enter the insulation, causing more serious leaks.
- Roof Structures Just like sloped shingle roofs, flat roofs are vulnerable to leaks around areas where a structure rises up through the roofs surface. These structures may include plumbing vents, gas lines, pipes, and other building elements.
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Building A Flat Roof Right
Here’s how the pros construct one so it stays tight and tight
Flat roofs aren’t architecturally logical, as rain and snow will shed much more quickly off a sloped roof. Yet for historic Modern-style buildings like This Old HousesCambridge TV project, flat roofs are at the core of the architecture, meant to reflect the broad horizontal lines of the natural landscape.
Of course, you don’t need to live in a modern house to deal with a flat roof. Traditional homes often have sections of flat roofover shed dormers, above porches and garages, and on balconies. And their horizontal lines abound in the West and in urban areas.
But flat roofs take a pounding from harsh weather, which is why they rarely last as long as a good sloped roof. Fortunately, modern materials for covering flat roofs have improved considerably over the past two decades some carry warranties of up to 20 years, approaching those for sloped roofing.
“If you build and flash one rightand keep it cleana good flat roof won’t leak,” says TOH general contractor Tom Silva, who had seven different flat roofs to contend with on the Cambridge project house. He sealed them all with a glue-down EPDM rubber membrane system, a favorite of his because it’s light, quick to install, and requires no special equipment.