(BUR Roofing Systems)
Built-Up Roofs (BUR) Built up roofing systems, referred to by the acronym BUR are one of the oldest and most durable systems available due in large part to the success and proven reliability of BUR. The stock of 20, 30 and 40-year-old BUR roofs still in excellent condition attests to this fact.
These roof systems are commonly referred to as "tar and gravel" roofs. BUR systems generally are composed of alternating layers of bitumen and reinforcing fabrics that create a finished membrane. Its multiple layers provide extra protection and perform well in extreme weather conditions. Built-up roofs are especially resistant to damage from wind, hail and driving rain.
They are easy to repair and ideally suited for applications requiring a high level of redundancy. The number of plies in a cross section is the number of plies on a roof: The term "four plies" denotes a four ply roof membrane construction. Sometimes, a base sheet, used as the bottommost ply, is mechanically fastened. Built up roofs generally are considered to be fully adhered if applied directly to roof decks or insulation.
Points to Consider For Installing A BUR Roofing System
Full removal of the existing roof, the amount of slope the roof has, weather conditions, as well as several other criteria contribute to the longevity of a roof's service life. Typically, if you remove an old roof down to the deck before installing a new one, then the new roof will last longer because you can identify and repair any damaged decking.
Also, the steeper the slope and the less severe the weather conditions, the longer a roof will last. High winds and hail can do a roof in rather quickly. But remember, the number one ingredient to a good roof system is proper installation.
When purchasing a new roof system, there will be two warranties to consider. First, there will be the manufacturer's warranty. In general, these warranties cover defects in the manufacture of the roof membrane. Once the project is complete, be sure the contractor provides you with a certificate for your records. Second, the roofing contractor will provide you with a warranty covering his workmanship. Typically, this will cover installation and related issues. The warranty should contain what items are covered and what will void them. Many contractors offer one year or two years of coverage; however, we offer up to seven years depending upon the system.
How Do You Know If A BUR Roofing System Is Right For You?
Your property was originally designed and built with a BUR roofing system
Due to the wide range of benefits most commercial properties were designed using a Built-Up Roofing System
Sections of your roof are virtually flat with little or no drainage
Other roofing systems such as mod-bid or TPO are not allowed by Florida Building Code for low sloped or flat roofs since they require slope for drainage and to prevent ponding water which will prematurely deteriorate the roof surface. A properly installed mod-bit roof will require tapered insulation and water-diverting crickets making it more expensive then a BUR roof
Benefits of a BUR Roofing System
- It is the most rugged and longest lasting roof system available. Unlike single layer systems such as TPO, the BUR roof replacement is not susceptible to punctures from foot traffic, cigarettes, dropped tools or parts, falling debris, animal activity, etc.
- It has a life expectancy of 20+ years and is virtually maintenance free
- It provides redundancy of multiple waterproofing layers formed into a monolithic sealed system that does not allow water under the roofing system
- It has a Class A fire rating which is the most stringent rating available for exterior fire resistance
- If your building has a virtually flat roof that was originally designed for a BUR roof system, other roofing systems such as Mod-bit or TPO will not be appropriate since they require a quarter inch or greater slope to prevent ponding water. It is against building code to install these types of membranes on flat roofs without proper slope for drainage
- The BUR roofing system is designed to accommodate ponding water. Although other roofing systems may initially be less expensive, they can be significantly more expensive long-term since they will fail prematurely due to ponding water which deteriorates the roof surface
- We have the ability to design roofing systems that are eligible for up to 25 years with no dollar limit (NDL), no penal sum/prorations that cover LABOR and MATERIALS
Advantages of Built-Up Roofing Systems
- Multi-Layer Protection - the multiple layers of bitumen and bitumen saturated “felts” make a water-resistant barrier capable of providing many years of reliable protection from the elements
- UV Protection - BUR roofing membranes can be protected from solar radiation by embedding gravel in the bitumen, applying a surface coating or applying a granular-surfaced “cap” sheet
- Thermal Performance - Built-up roofing systems exhibit exceptional resistance to the conduction of heat between the exterior and interior of a building, resulting in noticeable reductions in heating and cooling costs
- Fire and Uplift Resistance - Built-up roofing systems are tested through Factory Mutual Research Corporation to meet very strict fire resistance requirements and ensure adequate uplift resistance under extreme wind conditions
- Economy - Compared to other high performance commercial roofing systems, built-up roofing is one of the best investments on the market due to its competitive cost per year of expected service life
Limitations of Built-Up Roofing Systems
- Installation, must be highly trained
- Asphalt vapors when installing it
- Repairs should only done by skilled technicians