Built up roofing is a type of roofing system that has been used in building construction for many years. It is commonly referred to as BUR or tar and gravel roofing. It involves laying down several layers of tar paper, usually alternating with layers of bitumen or asphalt, and then covering the entire surface with gravel.
The layers of tar create a waterproof barrier, while the gravel adds additional protection from the elements and prevents erosion of the underlying tar. Built up roofing systems are extremely durable and are known for their longevity; they can often last for more than 20 years without needing to be replaced.
They are also relatively inexpensive to install when compared to other roofing systems. As such, they are a popular choice for commercial and industrial buildings, as well as numerous residential applications.
How thick is built up roofing?
The thickness of built up roofing depends on the type of materials used and the building’s design. Generally, built up roofs consist of four plies of tar and gravel and are usually between 60 and 90 mils thick, with a minimum of four plies.
However, some built up roofs may be as thick as 240 mils (1/4 inch) or more depending on the building’s design. In addition, the thickness of built up roofs can vary due to the different types of waterproofing layers, insulation, and other components.
For example, a built up roof over a mobile home may be thinner to accommodate the weight of the structure, while a built up roof over an office building may be thicker to provide extra layers of protection.
What is the difference between built up roofing and single ply roofing?
Built-up roofing, also known as BUR, is one of the oldest and most traditional types of roofing systems. It is made up of multiple layers of felt that are saturated in bitumen, such as asphalt and tar, then topped with a layer of asphalt gravel.
BUR is typically used in flat or low sloped roofs and is long-lasting, generally between 20-30 years.
Single ply roofing is a lighter, simpler solution for flat and low sloped roofs. It is a pre-fabricated sheet, typically made of rubber, PVC, or TPO, which bonds together when installed. Unlike BUR, single ply roofing is more lightweight and can be installed on almost any slope roof.
It is also typically more affordable, easier to install, and usually comes with a manufacturer’s warranty for up to 20-30 years. However, due to its pre-fabricated design, single ply roofing may be less resistant to weather elements and more prone to punctures and tears.
Is a built up roof tar and gravel?
A built up roof, also known as a BUR, is a traditional roof system that has existed for decades. It consists of alternate layers of tar and gravel applied on top of felt or some other type of tar paper.
The gravel serves several purposes; it adds weight to help hold the tar paper in place, shields from ultraviolet radiation, adds insulation and provides an additional layer of waterproofing. Built up roofs are typically used on flat or low-pitched roofs, as they provide additional strength and protection compared to other types of roof systems.
It is important to note, however, that built up roofs require regular maintenance in order to ensure they remain in good condition and do not develop any leaks or other damage.
What are the layers of built up roof called?
The layers of a built up roof (sometimes known as a ‘tar and gravel’ roof) are typically made up of several waterproofing materials and protective layers. The most common type of built up roof consists of four main components: a moisture barrier, a base sheet, a reinforcing scrim, and a surface coating.
The moisture barrier (also referred to as the ‘underlayment’) is the first layer of protection and is usually made up of either a rubberized asphalt material or a flexible material such as polyethylene.
This layer helps to protect the lower layers of the roof from moisture and debris.
The base sheet is the second layer of the roof and is typically made of asphalt-soaked felts or a smooth, non-fibrous material like roll roofing. This layer provides an additional layer of waterproof protection and helps to strengthen the roof’s structure.
The reinforcing scrim is the third layer and is usually made of closely woven organic or synthetic material, and is used to reinforce the base sheet and provide an even, smooth surface.
The surface coating, which is the fourth and final layer, consists of either bitumen-based roofing material or layers of gravel held together with asphalt. This layer helps to create a waterproof seal and provide additional UV protection.
By adding these four layers, a built up roofing system should be able to protect the building from environmental damage, such as wind and rain, for more than 20 years.
How many years does a tar and gravel roof last?
On average, a tar and gravel roof should last between 20-30 years. The exact lifespan of a tar and gravel roof is determined by several factors, including the quality of the materials and the local weather conditions.
The roof will last longer if it’s well maintained, with regular repairs and maintenance, and if it has been applied with extra protection such as a sealant or coating. If a tar and gravel roof is installed properly, in an area with a mild climate and is well maintained, it should last up to 30 years.
In contrast, if the roof is exposed to extreme weather conditions such as heavy rain and hail, it will likely need to be replaced or repaired much earlier in its lifespan. Over time, tar and gravel roofing materials tend to become brittle and can easily become damaged in the face of extreme weather, which can drastically shorten its lifespan.
What is a tar and gravel roof called?
A tar and gravel roof is also known as a built-up roof (BUR). It is a type of roofing system that is composed of overlapping layers of felt, hot tar, and gravel or mineral-based materials. The felt layers are often referred to as plies, while the tar layers may be referred to as moppings.
The gravel layer is installed over a hot mopping of asphalt, coal tar, and then sealed with a hot asphalt. The individual layers are saturated and laminated together with hot asphalt and adhesive. This type of roofing system is most often used for flat or low pitched roofs, and has a proven durability track record of 30-50 years.
This type of roof system is preferred in warm climates due to its reflectivity and heat resistance, and is low maintenance overall.
Why do they put gravel on rooftops?
Gravel is often found on rooftops due to its numerous benefits. Gravel helps reduce heat absorption by reflecting sunlight and can act as an insulation barrier to reduce heat loss in colder climates.
Gravel is also a great choice for fireproofing a roof, as the gravel particles act as a shield from the heat generated by a fire. In addition, gravel provides excellent drainage capabilities, which helps protect the roof and home from things like moisture and ice.
Finally, gravel can also help protect the roof from high winds and debris, which could otherwise cause damage. Overall, gravel is a great choice for adding an element of protection to a rooftop.
Do you need gravel on a flat roof?
Whether you need gravel on a flat roof will depend largely on the type of roof you have and what you intend to use it for. Generally, gravel is not an absolute requirement for flat roofs and many flat roofs are not built with gravel.
However, in some cases, gravel can be beneficial.
Gravel provides a number of advantages on flat roofs. Firstly, it can help to protect the roof from UV rays and can also provide some level of insulation to help reduce energy costs. Gravel is also used to protect the roof from physical damage caused by the elements, such as hail and wind, as the stones will deflect the force of the weather.
Additionally, gravel helps to act as a ballast, reducing the risk of the roof blowing off in high wind conditions.
Finally, gravel also has an aesthetic value and can help to protect underlying layers of the roof from heat and other conditions. The material also helps to reduce the noise of rain which is an additional bonus in some cases.
It is important to note that the type of gravel used is an important consideration. Loose gravel is not suitable for flat roofs and only crushed stone with specific size parameters should be used. Furthermore, it may also be necessary to include other layers with the gravel to provide a secure seal and protect underlying layers from the elements.
Overall, whether gravel is necessary on a flat roof depends on the type of roof, what you plan to use it for, and where it is located.
How many layers is a built up roof?
A built up roof (BUR) is a multi-layered flat roof consisting of alternating layers of tar and asphalt-saturated felt, which is typically topped with a layer of gravel. The number of layers a built up roof has depends on the specific application and environment, but generally, the minimum number of layers recommended by the National Roofing Contractors Association is four.
Most BURs consist of at least four layers of felt, two or more coats of hot asphalt, and a final layer of gravel for protection. Depending on the climate, building materials, and other specific requirements, an additional layer of modified bitumen or even another layer of gravel can be added.
At the end of the day, a built up roof functions as more than the sum of its parts – it’s designed to provide a sturdy system that works with the building to maintain a controlled environment inside while keeping out elements like water and wind.
As such, the number of layers in any individual built-up roof will vary depending on the needs of the structure in question.
What is built up roofing material?
Built up roofing (BUR) material is a classic form of low-slope roofing that is composed of several layers of alternate layers of bitumen and reinforcing fabrics that create a finished membrane. It is most commonly applied to flat or low-sloped roofs that have a pitch of 2/12 or less.
The number of layers will depend on the type and size of the project and the desired performance characteristics. The membrane is typically covered with gravel or other ballast to hold the membrane in place and protect it from the sun’s UV radiation.
The built-up roofing membrane is made up of several layers of bitumen that are alternated with layers of reinforcing fabric. Depending on the type of bitumen and reinforcing fabric used, the overall thickness of the membrane can range from two to more than ten millimeters thick.
The bitumen is applied in hot liquid form and will expand and contract with changes in temperature. The reinforcing fabrics serve to stiffen the membrane, reduce shrinkage and provide additional protection from the sun and the elements.
Built-up roofing material is an economical and dependable form of low and flat-slope roofing, making it a popular choice for many commercial, industrial, and institutional structures.
How long will a built up roof last?
The longevity of a built up roof depends on several factors, such as the quality of construction, maintenance, the geographic location and local climate of the roof’s location, and the type of materials and layers used in its construction.
In general, a properly installed and maintained built-up roof system can last anywhere from 15 to 25 years. However, some may last up to as much as 30 years, depending on the environment. To extend the lifespan of a built-up roof, regular maintenance and inspections are key.
It is important to check the structural, waterproofing, and other components of the roof system to make sure that the roof is in good condition and not at risk for potential damage or leaking. Additionally, it may be beneficial to use weather-resistant, reflective coatings on the roofing membrane to help protect from further damage caused by the elements.
Are built-up roofs good?
Yes, built-up roofs are generally considered to be a good roofing option. They are often the go-to choice for low-slope commercial roofing, as they provide a long-lasting, sturdy, waterproof barrier, even in areas where rain and snow can create a lot of wear and tear.
Built-up roofs are also considered to be very durable and can typically last a couple decades or more, depending on the maintenance they receive. They also don’t require many replacement parts, which is an added bonus.
Additionally, built-up roofs are typically easy to repair and maintain, as long as they are properly cared for. This often includes regular inspections and resealing the seams. Overall, built-up roofs offer a great balance of quality and affordability, making them a great choice for many commercial buildings.
Why is it often difficult to identify flaws in the membrane of a built-up roof?
It is often difficult to identify flaws in the membrane of a built-up roof because built-up roofs are comprised of multiple layers of material, making it difficult to detect weaknesses or flaws in any individual layer.
Additionally, built-up roofs are not always easy to access, which can make it difficult to detect any potential flaws in the membrane, unless the roof is being inspected. Furthermore, built-up roofs are typically installed on a flat surface, making it difficult to examine the materials that comprise the membrane.
Lastly, many built-up roofs are designed with several overlapping seams, requiring inspectors to identify even the smallest of flaws in order to detect potential weaknesses or defects. All these factors make it difficult to accurately identify any flaws in the membrane of a built-up roof.
What are built up roofs designed to do?
Built up roofs (BURs) are a widely used roofing system designed for low-slope roofs. They are created by alternating several layers of waterproof material and reinforcing fabrics. BURs are designed to be highly durable and watertight, capable of withstanding extreme temperatures, wind, rain and hail.
In addition to providing a waterproof barrier, these types of roofs are designed to protect the building from ultraviolet light and other environmental conditions. Additional benefits of the BUR include long life expectancy and relatively low maintenance requirements.
They also provide excellent insulation for the building and can be a cost-effective option for large commercial or industrial roofs.
How often should roof Be Replaced?
The exact time frame depends on a variety of factors, including the type of material used, the climate the roof is exposed to, and the exposure to elements. Generally, asphalt shingles can last between 15 to 30 years, whereas a metal roof can last from 40 to 70 years.
A more accurate timeline can be provided by a professional roofer who is familiar with the local climate and the materials being used. Generally, it is recommended to have a roof inspection at least once a year to ensure that any issues are caught early and repairs can be completed before they result in major damage.
Additionally, any significant event (hail, windstorms, wildfires, etc. ) should be followed up by an inspection to check for any damage that may have occurred.
How often does a flat roof need to be replaced?
The frequency at which a flat roof needs to be replaced largely depends on a few factors, such as the type of roofing material used, the quality of installation, and the wear and tear it has endured.
Generally speaking, if the roof was installed properly and maintained regularly, you can expect a flat roof to last anywhere from 10-20 years. So, if your roof is nearing this age, you may want to think about replacing it soon.
However, certain roofing materials may have a lifespan significantly shorter or longer than 10-20 years. For example, built-up roofing and EPDM can have lifespans of up to 20 years. On the other hand, a single-ply roof membrane typically lasts for about 10-15 years.
It’s also important to consider the age of the roof and the amount of damage it has sustained that could cause water leaks. At the very least, a qualified roofer should inspect the roof the every year to check for signs of damage.
If the roof has a lot of wear and tear, you should consider having it replaced sooner rather than later.
Ultimately, it’s best to consult a licensed roofer and have them evaluate the condition of your flat roof in order to determine how often it should be replaced. They will be able to assess your specific situation and provide you with an accurate recommendation as to when you should start thinking about replacing your flat roof.