When installing a new roof, commercial property owners must consider the employees,
equipment and inventory they are protecting. With many different asphalt roofing products and
installation methods available on the market, it is important to understand how to choose the
right system and get the most from an investment.
What Types of Roofing Systems Are Available?
A whole-system approach to low-slope roofing utilizes
long-term durability and redundant layers to provide
some of the best protection and reliability available.
Options include the following:
• Built-Up Roofing (BUR)
• Atactic Polypropylene (APP)
• Styrene Butadiene Styrene (SBS) modified systems
How Do These Roofing Systems Protect a
Building and its Assets?
Base sheets, interplies and cap sheets work
with asphalt and adhesives to create a longlasting, durable and redundant installation
comprised of multiple layers that provide a
water-resistant barrier.
What Are the Different Installation Options?
Different roofing systems can be applied in a variety of ways, including:
• cold-adhesive technology
• heat-welding
• hot asphalt
• self-adhering
How Do I Ensure My Roof is Installed Properly?
Prior to work beginning, ask your installer for the manufacturers’ system specifications to make
sure products are compatible. You can also request documentation of conformance to the
industry testing requirements from Underwriters Laboratories (UL), FM Approvals and ASTM
International. This documentation will demonstrate that the various components used in the
construction of your roofing system have been properly evaluated.
Low-Slope Inspection & Maintenance
By properly maintaining a low-slope asphalt roofing system,
building owners can greatly impact its service life, reliability and
performance. The Asphalt Roofing Manufacturers Association
(ARMA) has identified six steps all owners should follow to properly
care for a roof.
Step 1) Maintain historical records.
A building owner should keep a historical
record of the roof system. This should
include information about the following:
• original installation
• roof plan
• membrane type
• system components
• contractor’s contact details
• membrane manufacturer
• warranty
All roof inspections, maintenance and
repairs should be documented as well.
Step 2) Control roof access.
Building owners should allow roof access only to trained
professionals and only when maintenance is required. Roofs are not
generally designed for extensive foot traffic.
Step 3) Conduct regular inspections.
Each spring and fall, a roof should be inspected by a professional roofing
contractor. The contractor should inspect each visible component of the roof
and identify areas that may require additional attention. Inspections can help
to identify potential roof damage or leaks before they occur.
Step 4) Ensure routine maintenance.
Routine maintenance can be conducted by the building’s trained
maintenance personnel. This includes removing debris, such as
construction waste or tree limbs from a roof. Leaves and dirt
should be removed from drains and gutters to ensure proper
drainage. Tree limbs that overhang a roof should be trimmed.
Step 5) Report leaks or roof damage immediately.
If evidence of roof damage or a leak is found during routine
maintenance or an inspection, building owners should contact a
roofing contractor immediately to address the issue before it
gets worse.
Step 6) Use a professional roofing contractor for major
maintenance and repairs.
All major maintenance procedures and roof repairs should be
handled by a professional roofing contractor after consulting the
membrane manufacturer. Do not attempt these actions yourself.
By following these steps, owners
can maximize the value and service
life of their roofing investments.
The formation of a “tobacco juice” residue, so named for its color, has been widely attributed
to the weathering of asphalt roofing (i.e., roof coatings, base and cap sheets and shingles – to
name a few) or the exudation of asphalt fractions from the roofing material.
In fact, similar brown residues have been found on other, non-asphaltic materials, indicating
that the phenomenon can be environmental in nature and not wholly attributable to asphalt
roofing. An investigation of this phenomenon concluded that environmental contamination or
pollutant deposition was the major contributor to tobacco juicing.
Factors commonly present with “tobacco juicing” are excessive air pollution accompanied by
nighttime dew conditions and prolonged lack of rain. Air pollutants can collect on roof surfaces
with the formation of dew and subsequently run down onto lower roof surfaces, fascia, and
other finish surfaces. For steep slope applications, such as asphalt shingled roofs, tobacco
juicing may drip off the shingles and stain the adjacent components (see photos 1-3 below for
examples). This accumulation of residue can continue until the surfaces are washed or
significant rainfall occurs. The residue typically will not affect the performance of the roof and
should not be considered a performance problem.
For low slope applications, if any accumulation of this liquid residue occurs prior to coating, the
proper bonding of coatings to the roof surface may be adversely affected. Preparation of the
roof for coating should conform to the recommendations of the Roof Coatings Manufacturers
Association (RCMA) and the Asphalt Roofing Manufacturers Association (ARMA) to help ensure
proper adhesion. Coated smooth-surfaced roofing systems which are continuously subjected to
tobacco juicing should be hosed off regularly, as tobacco juicing residue may cause the peeling
of acrylic and aluminum coatings.
Though it may not be possible to control environmental elements that cause the formation of
the residue, the following recommendations can be utilized by the specifier, contractor or
owner to minimize the aesthetic conditions associated with tobacco juicing.
• Require edge metal with a drip lip on parapet walls where the metal slopes outward, is
rounded, and has no existing lip on the outside edge to assure the residue-laden runoff
will fall away from the building.
• Hose down the roof at regular intervals during long, dry periods of the first summer
after installation. Note: this is not recommended where proper fall protection is not in
place, or where steps have not been taken to protect exterior surfaces that may come
into contact with the wash-off, e.g., siding on a house without gutters.
• For low slope applications, the use of an aluminum coating or acrylic coating can
minimize the aesthetic conditions. Coat all asphalt emulsions after they are thoroughly
dried. Coat plastic cements and other solvent-based vehicle asphaltic products after
they have cured for at least 30 days.
• Consult the specific material manufacturer for additional recommendations.
The effects associated with tobacco juicing can be minimized if the necessary steps are taken by
the specifier, contractor and owner.
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Introduction
The Asphalt Roofing Manufacturers Association (ARMA) recommends that the structural roof
deck meet certain minimum requirements to be an acceptable substrate for the specified
roofing system. Generally, all decks should be clean, dry, and securely fastened to the building
structure with no abrupt level changes exceeding 1/8”. Roof deck deflection should never
exceed 1⁄240 of the span under total design loads — including rooftop traffic. Requirements of
the roofing system manufacturer, insurer and local building code must also be met when
designing and applying the roofing system.
The following are suggested for various roof deck types:
I. Steel Decks
Steel decks should be installed in a way that allows the rib spacing to be uniform and straight so
that: (1) the roof insulation boards may be laid with side joints parallel (with end joints
perpendicular to the ribs); and (2) the roof insulation edge is supported by the flanges.
Deck specifications shall comply with all applicable code requirements. They should also meet
the requirements of the Underwriters Laboratories “Building Materials Directory” and, when
applicable, the requirements found in Factory Mutual Global’s RoofNav and “Property Loss
Prevention Data Sheet 1-28.”
II. Wood Decks
(A) Wood Planks: Wood deck material should consist of kiln-dried, tongue and groove, shiplapped, or splined boards. All boards must have a bearing on rafters at each end and be
securely fastened. They should have a minimum of splits and knotholes, and under no
circumstances can these boards be warped or cupped. All holes over 1⁄4” should be
appropriately covered. Individual boards must not exceed 8” width and must be no less
than 1” thick (nominal). There should be a 1⁄8” space between boards to allow for
expansion. Wood deck preservatives and/or treatments must be compatible with the
type of bitumen used.
(B) Plywood and Oriented Strand Board (OSB) Decks: Individual roofing manufacturers
approve either or both plywood and OSB Performance Rated Panels for use as
sheathing. These panels should be a minimum thickness of 7⁄16” for OSB and 15⁄32” for
plywood. The panels must be manufactured with a water-resistant adhesive and should be labeled “Exposure 1”. There should be a minimum of holes and voids within and on
the surface. The panels should also be marked properly as “Performance Rated Panels”
by either APA – The Engineered Wood Association or another recognized testing agency.
Install so that all edges are supported or clipped to the adjacent sheet. *Fire treated
plywood and particle boards are not recommended.
III. Concrete Decks
(A) Poured Structural Concrete Decks: These decks typically vary from 4” to 12” in thickness
and must be properly cured prior to application of a roofing system (normally a
minimum of 28 days). Curing agents must be checked for compatibility with the roofing
system to be installed. After installation, the underside of these decks must continue to
remain unobstructed and should be exposed, or they should be poured over vented
metal forms to allow the escape of water vapor. A primer compatible with the bitumen
or adhesive used to install the roof system should be used on these decks.
(B) Pre-cast Structural Concrete Decks: Joints must be filled with a masonry grout to correct
imperfections between slabs and feathered to provide a slope of not greater than 1/8”
per foot. When the membrane or roof insulation is adhered directly to the deck, use a
concrete bituminous primer that meets the membrane manufacturer’s requirements
and is compatible with the type of bitumen used.
(C) Pre-stressed Concrete Decks: Because of variation in camber and thickness of prestressed concrete decks it is recommended that a minimum 2” lightweight concrete fill
be installed over these decks.
(D) Lightweight Structural Concrete Decks: Refer to ARMA’s Lightweight Structural Concrete
Roof Decks Statement, which can be found here.
IV. Lightweight Insulating Concrete Decks
Lightweight insulating concrete decks, which are placed as a slurry, contain more moisture than
many other roofing substrates. Retained moisture may contribute to problems with the roofing
systems installed over such decks when proper precautions are not taken.
When these decks are used as a substrate for built-up or modified bitumen roofing, the
following should be considered:
• When lightweight insulating concrete is poured over a galvanized metal deck, the metal
deck should be perforated to provide underside venting. Topside pressure relief is also
suggested.
• The base ply of the roofing system should be attached using appropriate mechanical
fasteners.
• Pull-through resistance for fasteners should comply with the membrane manufacturer’s requirements.
• The deck applicator and deck manufacturer should certify, in writing, that the roof deck
was installed in accordance with the deck manufacturer’s recommendations and is
satisfactory to receive the roofing system.
• The roofing contractor should install the roof in accordance with the roofing
manufacturer’s recommendations for application over lightweight insulating concrete
decks.
V. Cementitious Structural Wood Fiber Decks
These decks should be bonded by binders that are not affected by water. The units should be
attached to the building structure with mechanical fasteners to prevent movement and to
provide the required uplift resistance. The base ply should be attached using fasteners
recommended by the structural wood fiber and base ply manufacturers.
Typically, manufacturers do not recommend that insulation or a membrane be fully adhered to
these decks. The roofing contractor should install the roofing system in accordance with the
roofing manufacturer’s recommendations.
VI. Poured Gypsum Concrete Deck
Gypsum is a mineral, calcium sulfate, which is initially heated to remove hydrated water which
it readily reabsorbs when being made into panels or being poured in the field. A more common
name is plaster. Upon adding water, rehydration occurs and the gypsum sets up into a
monolithic nailable substrate. Reinforcing wood chips and shavings are usually added for
additional strength. Gypsum is noncombustible and nailable when fresh. Gypsum decks were
manufactured as precast panels or poured in place in the field. Gypsum decks are typically a
minimum of 2″ thick. Most gypsum deck projects will be reroofs or tear-off.
The precast panels are generally designed with tongue and groove edges that reinforce
adjacent panels and accommodate bulb-T roof truss construction. Precast panels harden
significantly upon aging.
Poured deck systems contain some excess water; provisions must be made for moisture to
escape so as to avoid related moisture problems for roofing systems. Roofing systems should
be attached to this deck using a nailed base sheet. Special fasteners are available for this
purpose. Direct solid attachment of the roof membrane to this deck is not recommended;
occasional shrinkage cracks in the deck could result in splits in the roof membrane.
Typically, manufacturers do not recommend that insulation or a membrane be fully adhered to these decks. The roofing contractor should install the roofing system in accordance with the
roofing manufacturer’s recommendations.
Flat Roofing in Chicago
Introduction
When you’re ready to install a flat roof in Chicago, there are many things to consider. This guide will help you learn about the different types of flat roofing materials so that you can find one that’s right for your needs.
Flat roofing is durable and can last for an average of 15 years.
Flat roofing is durable and can last for an average of 15 years. It’s less likely to leak than a pitched roof, which means you won’t have to worry about water damage in your home or building. Flat roofs are also more energy efficient than pitched roofs because they don’t extend out away from the walls to catch wind or rain, so there’s no room for heat loss (or gain). If your property has a flat roof, consider all these benefits when deciding whether it needs repairs, replacements or maintenance work every year—or if you’re just looking for ways to extend the life of what you’ve got!
Flat roofing typically needs to be replaced before a pitched roof.
Flat roofs are typically much harder to access than pitched roofs. This makes them more susceptible to damage and leaks, which can result in water damage and mold growth. Flat roofs are also more expensive than pitched roofs because they require more maintenance and replacement.
A flat roof requires regular maintenance to thrive.
A flat roof requires regular maintenance to thrive. This includes keeping it clean and checking for leaks, repairing any leaks you find, inspecting for signs of wear and tear, and making sure the roof is properly insulated.
If you don’t maintain your flat roof correctly, then it won’t last as long as it should. The good news is that there are some simple steps you can take to ensure that your flat roof lasts as long as possible.
Main flat roofing types are TPO, EPDM, BUR, and PVC.
- TPO (thermoplastic polyolefin) is a flexible, thermoplastic material.
- EPDM (ethylene-propylene-diene monomer) is a flexible, rubber-like material.
- BUR (built up roofing) is a rigid, mineral-based material that’s made from layers of single ply sheets with sand or gravel added as an aggregate between each layer to create more chip resistance.
- PVC (polyvinyl chloride) is a rigid plastic sheet that can be used on flat roofs and can include insulation in its design to keep heat in during winter months and reduce energy costs by blocking UV rays from reaching your home during summer months.
TPO is ideal for larger commercial buildings.
If you have a large commercial building with a flat roof, TPO is ideal for your needs. TPO is a synthetic rubber membrane that’s flexible and durable, making it an easy choice for commercial buildings where there are different activities taking place on the roof such as machinery or vehicles.
Additionally, because TPO can be applied over existing roofing material, it is often chosen by property owners who don’t want to replace their current roofs but do want to improve their building’s energy efficiency and performance. The membrane can withstand extreme weather conditions such as heavy snowfall or high winds which makes it ideal for commercial buildings located in areas that experience extreme weather conditions during winter months like Chicago does!
EPDM is suitable for smaller commercial and residential buildings in Chicago.
EPDM is a synthetic rubber that is flexible and resistant to UV rays. It is a good choice for flat roofs in Chicago because it has high resistance to puncture, tear, abrasion, and impact from hail and falling debris. EPDM also has excellent resistance to chipping, cracking or peeling due to aging or weathering.
EPDM is used on residential and commercial buildings in Chicago because it has low outgassing levels that are not harmful to humans or the environment. Its physical properties make it highly resistant against fire damage as well as water seepage caused by ice dams during winter months when temperature fluctuates greatly between day time highs (60s) and night time lows (-10s).
BUR is made of hot tar (bitumen) and gravel or mineral granules and it’s used on commercial buildings in Chicago.
BUR is made of hot tar (bitumen) and gravel or mineral granules, and it’s used on commercial buildings in Chicago. BUR is used on flat roofs that are less than 50 feet wide, or less than 6 inches deep.
PVC is made from sheets of vinyl plastic, which is chemical-resistant and waterproof making it ideal for chemical storage rooms where other materials might not stand up to the exposure to toxic chemicals.
PVC is a good choice for chemical storage rooms. It’s resistant to chemicals and water, making it ideal for chemical storage rooms where other materials might not stand up to the exposure to toxic chemicals. PVC is also an affordable option, which means you’ll save money in the long run by choosing PVC over other types of roofing material like metal or wood. You can have your PVC flat roof installed quickly and easily with minimal disruption to your home or business while also maintaining its appearance with little effort on your part.
Choosing the right material can help maximize durability and longevity.
If you’re thinking about getting a new roof, you’ll need to consider a few different factors. One of the most important decisions to make when buying a new roof is whether you want it to be made from TPO rubberized roofing membrane or EPDM rubberized roofing membrane. Both are made with high-quality materials that can last for 20–30 years and withstand even the harshest Chicago winters.
The other option you have for your flat roof is BUR (built-up), which is usually composed of hot tar and gravel or mineral granules.
Conclusion
If you’re looking for flat roofing in Chicago, there are many options to choose from. It all depends on what kind of building you have, what type of material you want, and if it needs to withstand certain climates (rainy winters). For example, if your house is older with no insulation underneath the shingles then maybe it would be worth investing in some new ones since they might not last as long as expected. On the other hand if your business has a small warehouse where water or chemicals may leak onto it regularly then choosing PVC could be a better option because it won’t corrode from these harsh conditions.
Quincy Sizemore
Third Coast Exteriors
Owner