Roofing Terms
Whether you choose JW Roofing to install a great roof or choose another contractor, we believe you should be educated about your choice. Therefore, we have provided this list of roofing terms and explanations to help you pick the right roofing contractor. There are over 3000 contractors whose license allows them to roof or re-roof in Miami-Dade and Broward. Miami-Dade is also known to have one of the strictest building codes for roofs in the world. It takes skill and experience to get the job done right. In fact, the Dade county code is so strict there is an average inspection failure of close to 50 percent! Our last failed inspection was for a missing ladder (that the homeowner took down) over 2 years ago. Quality, experience and service are the reasons so many educated owners choose JW Roofing to install their new roof. JW roofing is proud to have one of the highest inspections pass rates because we ensure that one of our general contractors or our roofing contractor walks every roof before the city does their roof inspection -- having a crew chief with over twenty years of experience helps too!
Roofing Terms
Alligatoring:
Alligatoring is a condition that comes about from expansion and contraction of the roof material as the roof heats up in the day and cools overnight. Eventually the expansion and contraction causes the seams to open or the asphalt to crack. This commonly happens to most built up roofs and tar and gravel roofs at the end of their lifespan, which is typically 12 to 15 years in South Florida. Alligatoring is particularly noticeable if the bleed out is not protected on a built up roof. In most cases, if restoration is not an option, you should replace the roof as soon as possible.
Built-up Roofs (BUR):
BUR systems generally are composed of alternating layers of bitumen and reinforcing fabrics that create a finished membrane.
Deck:
A roof's deck is the flat non-structural area of the roof above the trusses. The deck is usually made of plywood, or concrete and metal but on older homes, it is often made of T&G boards. The deck type determines the material used to finish the roof.
Dimensional Shingles:
These shingles typically have a higher contrast and are usually thicker than three-tab shingles. They typically have a longer life expectancy and higher wind warranty than regular asphalt-shingle roofs.
Dormers:
Dormers create additional openings in your roof, which will affect your roof installation. One notable area is at the joints, which will need to be sealed with metal flashing. The style of dormer can also affect your roofing material. A shed dormer will decrease the slope of your roof over the opening. A gabled dormer often has higher pitches, which will shed water more easily.
Drip Edge:
A metal flashing or other overhanging component with an outward projecting lower edge is called Drip Edge. It is intended to control the direction of dripping water and help protect the underlying building. Drip Edge can be made from many materials, but for South Florida, the best is copper if you are located near the salt water. Copper coated stainless steel can be used to save costs if your building is further inland. Inland homes can use pre-painted galvanized metal.
Fascia Board:
Fascia board is the vertical exposed end of the roof, it is usually made out of 1x6 board, but other sizes are common in South Florida.
Flashing:
Flashing is the metal edging that is placed along roof valleys, intersections, dormers, chimneys, and the edges of the roof. It helps protect from water intrusion and guides water away from roof joints. Most flashing is made of galvanized steel or copper. Aluminum is not recommended in South Florida because of excessive expansion and contraction. Galvanized steel is inexpensive but needs occasional painting to prevent rusting. Copper flashing is the best option for homes near the beach or on slate roofs. Though it is expensive, copper flashing is beautiful and long lasting.
Metal Roofs:
Metal roofs have many advantages over tile and asphalt roofs. They typically are stronger, last longer and weigh less than a tile roofing system.
Modified Underlayment:
Also called 'Modified', this is considered a premium underlayment for tile. The SBS in Modified Underlayment gives the underlayment more flexibility, which may provide more protection during a storm.
Ridge Vent:
A ridge vent creates convection in the attic because the vent sits along the top ridge of your roof. As heat rises, it pulls cooler air from the soffit vents through the attic.
Roofing Felt (also called #30):
Roofing felt is the protective layer that sits between the roof sheathing and the shingles. At JW roofing our standard procedure is to use two layers of #30 on our shingle roofs.
Roof Pitch and Slope:
Roof pitch and roof slope are two terms that roofers often use interchangeably, but they actually mean different things. Slope is described in inches of vertical rise per foot of horizontal run. For example, a gently sloped roof that rises 4 inches for every 12 inches of house covering is said to have a 4-in-12 slope. Roof pitch is expressed as a fraction, the ratio of rise to the total span of the entire roof. The same gentle 4-in-12 slope translates into a 1:6 pitch.
Roof Restoration / Reflective Coatings:
This is one of several systems of waterproof coatings that can add over 10 years to the life of a flat roof for a fraction of the cost of a new roof. Additionally, some roofs that are over air-conditioned space may qualify for a rebate from FPL to help offset the cost. JW Roofing does not use the cheap reflective coatings; instead, we use only high quality restorative, water proofing products such as NeoGard and Gaco Western.
NOTE: Per Miami-Dade County building code, roof restoration products can only be applied to flat roofs.
Roof Types:
There are dozens of roof types around the world and many that are popular in South Florida. Some are better for the South Florida area like a hip roof which is best against storm winds. Other roof types like flat roofs perform poorly because of them amount of rain we get each year. Other styles such as a mansard roof can be beautiful and functional.
Shingles:
About 80% of homes in the U.S. have economical asphalt-shingle roofs. These are constructed of three foot sections that look like individual shingles when installed.
Soffits:
Soffits are the area under the roof overhang; the soffit should have the required amount of vents that allow your attic to breathe.
Underlayment:
Material which goes under the shingle or cap sheet which protects the roof deck.
Valley:
The valley of a roof is the line where two different roof slopes meet. A valley is one of the weakest parts of a roof and where most leaks occur. A true hip roof would not have any valleys.
Water Diverter:
Often seen over doorways, or at the bottom of a valley, a water diverter is a piece of metal that helps control the flow of water as it drains from the roof. In South Florida, these are often the cause of leaks and decking damage.
