What is a stone ballast roof?
A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material. The stones used in ballasted roofing are generally 1.5 – 2.5 inches in diameter and applied in a thicker layer. The stones are therefore much more substantial and hold up well under wind tunnel tests.
What is roof ballast for?
The ballast is used to keep the roofing system cool and of out of the sun’s harmful rays, thus keeping energy costs down. The gravel top coat is also extremely resilient to heavy foot traffic and high-wind scenarios.
Why do they put gravel on rooftops?
Gravel is added on top of tar (and sometimes Single-Ply EPDM) roof systems as protection from UV rays, foot traffic, and wear from weather. If the gravel stones break down, they become less effective and leave your important roof layers prone to wear and damage.
How much is a roof ballast?
In fact, the weight of the stone “ballast” is the only item holding the roof components in place. The weight can vary from 10 pounds per square foot (the minimum allowed by code) to 25 pounds or more.
Why do old Japanese houses have rocks on the roof?
Climate had a bearing on construction: In Kyoto in the late Heian and Muromachi periods, roofs were clad in thin wooden shingles so owners would put stones on top to prevent the shingles from flying away in the wind. The social status of the minka owner was indicated by the size and complexity of the building.
What is the purpose of gravel on shingles?
Why Do Roof Shingles Have Granules? Mineral granules were added to the design of shingles because they help protect your roof from excessive sun exposure, which can eventually lead to damage and hasten the need for a roof replacement.
Are tar and gravel roofs good?
Of all the flat roofing options, a tar and gravel roof is the most budget-friendly and can have a lifespan of up to 30 years with regular maintenance and repair. It provides excellent protection against UV rays, it is energy efficient and is a great option for windows and decks that overlook the roof.
Do you need stones on a flat roof?
Gravel and pea shingle have two primary purposes on a flat roof; they provide a ‘loading coat’ and they afford UV protection. As ballast, the gravel will help anchor the material underneath and lower the risk of it being blown off in high winds.
How long does a tar and gravel roof last?
around 20 to 25 years
The benefits of a tar and gravel roof are numerous. They tend to have a lifespan of around 20 to 25 years depending on the location and the structure of the rest of the property (barring any major natural disasters of course).
What is an inverted roof system?
The fact that the insulation is sandwiched between two membranes produces a vapour and water trap. The so called “upside down roof” is simply a rearrangement of the normal elements of a roofing system to try and overcome some of the disadvantages of the conventional arrangement.
What is a ballast block?
Take the humble ballast block—this seemingly simple piece of concrete that holds down a flat roof mounting system can lead to a lot of questions about weights, dimensions, and materials. Since finding and placing the blocks is the installer’s responsibility, it’s a common and sometimes last-minute concern.
What is ballast stone used for?
Ballast is material that is used to provide stability to a vehicle or structure.
What is ballast roof system?
Ballasted Roof System. Ballasted roof systems have been installed since the early 1970’s. They are known for their installation speed and pleasing aesthetics. Most ballasted roof systems use gravel stone that is similar to what would be used in landscaping. However, other ballasted systems use pavers, which are easier to walk on and can be color coordinated.
What is a ballasted roof system?
A “ballasted roof” generally refers to a single ply roof membrane that is held in place against wind uplift by loading the surface with either stone ballast or pavers. The membrane for such systems is usually not attached to the substrate, although some systems do have supplementary perimeter attachment.