Frequently asked Flat Roofing questions.

What do I need to know about selecting a professional roofing contractor?
A roof system is only as good as the roofing contractor who installs it. The roof system is assembled on your building by a roofing contractor, thus the quality of the system is very dependent on a knowledgeable installer. This is why it is always important to choose a roofing contractor with a dedication to quality and a proven record. It is also important to choose a contractor with experience in multiple roofing systems so that the proper system is specified for your building.

Furthermore, in the state of IL, a legitimate roofing contractor will have proof of a state of IL roofing license as well as workman’s compensation and general liability insurances. Commercial and Industrial Roofing Contractors require an UNLIMITED Illinois Roofing License, where as residential may simply possess a LIMITED license.

What is the best flat roofing system available?
There is no one single roofing system available. If there were a “best” system… only that system would be installed. This is a mistake some roofers may make. However a roofing system should be chosen based on the architecture and use of the building. There are various categories of roofing systems, and each system and category has its own use. These categories include: steep slope (shingles, cedar, tiles) , built up (pitch, asphalt), modified bitumen (cold process, heat applied), single ply (EPDM-rubber, TPO or PVC -plastic) and liquid elastomeric(Urethane, Acrylic, SEBS).  The key to a long lasting roof starts with the proper roof system for your building. A roofing contractor familiar with multiple types of roofing systems can assist you by specifying the proper system. (Learn more about low slope roofing options)

What about interior protection and dust?
If your roof is being torn off, dust on the interior can be a major concern, especially for a commercial property. Dust and small debris will make it’s way into the area around pipes, curbs and other penetrations in the roof. if the roof substrate is wood, debris will also make it’s way between the gaps around every board. If the roof substrate is gypsum it can be very dusty to repair. Normally interior protection is the responsibility of the building owner. However if interior dust protection is of a concern to you, make sure to discuss it with your Estimator, because there are options for interior dust protection.

What type of warranty should I look for and how do warranties vary?
There are multiple types of warranties for roofing systems. Workmanship, material, pro-rated, and limited are some types of warranties. Each warranty covers, or excludes, specific points of the roofing system.  A workmanship warranty typically will cover defects caused by workmanship. Workmanship warranties are usually offered by the roofing contractor and sometimes also the material manufacturer. A material warranty typically will cover defects in the roofing material and is usually offered by the manufacturer.  A pro-rated warranty is one that may last a certain term, but the dollar limit will decrease as time goes on.  The opposite is true for a Non pro-rated warranty which is good for the full purchase price and does not depreciate in value as the roof ages.

The terms and conditions of all warranties will be spelled out in the warranty documents and a qualified roofing contractor will be able to provide samples of these documents. Choosing a warranty that is right for you can be done by knowing your options, and knowing what your goals are for the warranty.

What types of roofing insulations are available?
Roofing insulation is an important component of the roofing system. Roofing insulation is not always used, for all roofing systems. This is why it is important to work with a roofing contractor who is familiar with multiple roofing systems.  Foremost the roof insulation provides insulating properties. Insulating properties are measured in R-value, which is the ability of the insulation to resist heat transfer. Roof insulation also provides an acceptable surface for installing some roofing systems. Some Roof insulation provides protection against foot traffic while others will improve drainage.

What type of maintenance is required on my new roof?
Just like the right roofing system varies from one building to another so does the required maintenance. Often times not much more than keeping the drains and gutters free from debris is all that is required. However it is recommended that comprehensive roof maintenance programs be set in place; this is especially true on detailed roofs, special-use buildings and buildings with older roofing systems.

What you need to know BEFORE putting a deck on your roof in Chicago

There are some things you need to know before building a plaza or deck on your roof in Chicago. First you may want to contact an engineer to determine if your roof can support the weight. Most masonry structures will not have a problem. You will also likely need permit approval, and the engineer or an Architect can aid you in the design and permit process. Make sure to contact a carpenter who has extensive experience building roof decks, because not all Chicago deck carpenters have the experience it takes to build a roof deck. Roof decks are not the same as patio decks or decks for the ground.

Please note: The purpose of this article is to inform you of what you need to know about the ROOF installed in conjunction with the deck.  The point is, your new roof will leak if the roof is not designed for the deck and if your deck is not properly designed and built for your roof.

By far the most important one thing you will want to do before placing a deck on your roof is ensuring that you have a long lasting water tight roofing system protecting your building. As a Chicago area roofing contractor we repair several roofs every year where decks are involved. The typical causes of these roof leaks is unskilled carpenters damaging the roof, or installing a deck on an old roof which may not have much serviceable life remaining. Probably the most common cause for roof deck related leaks is the common practice of putting an expensive roof deck over a cheap roof. The roof is something you do not want to “cheap out” on.

When you are deciding what kind of roof to install before installing the deck you should go for the best roof your budget can afford. Ask your roofer the system ratings, or in other words the manufacturer life expectancy, of the roofing system he intends to install. The common “norm” for most Chicago area flat roofing systems is actually only a cheap 10-year rated roof. Do you want to tear off your perfectly good deck in 10 years so you can replace that cheap roof? Going cheap on the roof now will cost you thousands of dollars extra in the long run.

When I say to install the best roof your budget can afford I would highly recommend a 20 year rated roofing system. If you are installing a modified bitumen roof system, which is a common Chicago area flat roofing system, a 20 year roofing system would be no less than 4 ply’s of membrane. Single ply roofing systems, such as TPO, PVC and EPDM are becoming more and more popular (Learn about your Low Slope Roofing Options). If considering a single ply roofing system, install no less than a 60 mill thick membrane and preferably thicker 80 or 90 mill membrane. The thicker the membrane the longer it should last.

A commonly neglected step which will cause damage over time to your roofing system is the improper installation of roofing insulation. Roof insulation is a common and necessary component of a roofing system. However not all insulations are the same, and the commonly used insulation will be a Poly IsoCyanurate insulation which afford high R value. However Poly Isocyanurate insulation offers very little in compressive strength. Meaning that very heavy wood deck you put on your roof will crush the insulation over time and then the deck will likely tear the roof membrane. A simple solution would be to install a medium-to-high density fiber board over the Poly Isocyanurate insulation. Fiberboard offers very little in the means of R value but has a very good pounds per square inch (PSI) rating meaning it will prevent the crushing of your insulation beneath.

Now protect that roof before the deck is installed. A simple way of doing this would be to install some loose laid scrap roofing membrane, or preferably some neoprene (rubber) walk pads. The goal is that no object, especially the roof deck, actually come in contact with the water proofing roof membrane.

A quick tip about the roof deck and future leaks. Have the roof deck designed and built to be modular, meaning the floor panels can easily be removed with minimal tools. This modular roof deck design will save you on labor in the future if/when the roof does leak. When the deck is built modular the entire deck won’t need to be disassembled to find and repair a pin hole in the roof.

The key to a long lasting roofing system beneath a roof deck is all in the planning and proper construction of the roof and deck. Your roofer should work with your carpenter to ensure your roof lasts and that deck stays useable for a very long time. Ask yourself, does your contractor have the skills and experience to install your roof deck without damaging your roof. Did your contractor bring up any of the above information?

Ice damming and Attic ventilation explained

Ice damming is a big problem in the Chicago area, as well as most of Northern North America. Ice damming and frost accumulation in the attic space are both caused by interior heat build up when there is snow sitting atop a shingle roof. This happens when an attic is not properly ventilated and/or insulated. The solution to ice damming or interior frost accumulation is 3 part.

The ice dam forms by interior heat from the building melting the snow, especially melting the snow from the bottom side. When the snow freezes, as the temperature drops at night, the ice expands and pushes under the shingles. In addition this ice creates a bump which restricts further run off, and with additional freeze-thaw cycles the ice damn becomes larger. Eventually the ice has nowhere to go except under the shingles and inside your building structure.

First your attic ventilation must be assessed for it’s overall effectiveness. Your attic ventilation should be balanced, and many roofs have undersized and/or imbalanced ventilation. Not only will an under ventilated attic cause ice dams, but it is also a major contributor to attic mold growth, de-lamination of your roof plywood substrate, premature decay of your roof shingles, and condensation build up.

A properly balanced ventilation system will preferably have an intake as well as an exhaust. The attic ventilation works on a principal of fresh air in, hot air out. Some common mistakes made by improperly trained contractors is the installation of exhaust vents low on the roof to be used as an intake. This causes more harm than good. A good intake will usually be in your overhang, also called soffit. When no overhang is present a behind-the-gutter fascia vent may be used. to create the air intake.

When it comes to the ventilation requirements, the typical rule of thumb is one square foot of net free area per 150 square feet of attic floor space. However this is only to be used as a rule of thumb, and the formula for determining proper ventilation is actually more complex based on the architecture of your building.

Exhaust vents can vary in size, type and style. Keep in mind there is NO ONE SIZE FITS ALL VENTILATION. A very common mistake made by improperly trained contractors is to install a ridge vent when the ridge is too short, such as many hip roofs. Most, not all, hip roofs have too short of a ridge line for proper exhaust ventilation. If a ridge vent is used when the ridge is too short, the ventilation is actually crippled preventing proper exhaust.

Another common ventilation problem is kitchen or bathroom exhaust vents dumping hot and moist air into the attic space. These kitchen and bathroom vents should be connected directly to a baffled and dedicated exhaust vent. The baffle in the vent is key in preventing backup of cold air. Typically a flex hose will be used to connect the exhaust fan in the kitchen or bathroom directly to the baffled roof vent.

Even with a properly ventilated attic space ice dams can still form on your roof. This is because of excessive conditioned hot air escaping from inside your building structure and accumulating within the attic. Most buildings with steep slope roof systems are very under insulated if built before the 1980’s. The suggested R value by the US Department of Energy, for the Chicago area, is about an R 49. Most local building codes require a minimum of an R 38 for steep slope roofs. Having said that, many older buildings with steep slope roof assemblies actually have an R value of about an 8. This means an extreme amount of heat is escaping into the attic, since the higher the R value means the greater resistance to thermal transfer.

The 3rd approach in preventing ice dams is perhaps the most common, but does not actually prevent ice dams from forming at all. It is actually a precaution from keeping the ice dam from getting inside once it has formed. This is an ice shield membrane sometimes called Grace Ice & Water shield, or Certainteed Winterguard. There are many ice shield membranes available on the market, what they do is seal down to the wood roof substrate (plywood or nominal lumber) and also seal around any nails. This ice shield should extend from your gutter line, at least 24″ past the exterior wall.

Please note: if you have 3′ of ice shield but a 2′ over hang you do not have enough ice shield. This is a common mistake made by many unqualified contractors. It is also suggested that ice shield be installed in all the problem areas, not just the gutter lines. These problem areas include valleys, where the roof meets the wall and all penetrations on the roof which are equally as prone to ice backup. When you replace the roof is the perfect time to install ice shield, and it’s a very cheap upgrade to do the roof right the first time.

In summary, your steep slope roof is a system which should be properly protected with ice shield, properly ventilated with adequate intake and exhaust ventilation, and properly insulated in the attic to block thermal transfer.

Frost In Your Attic

Did you know that Frost in your attic is caused very much by the same symptoms that cause Ice dams? A very common problem is improper roof ventilation. Mixing and matching roof ventilation can often cause more harm than good! Yes too much roof ventilation can be a bad thing if the styles and types of vents are mixed and matched. Roof ventilation is a science that is unique to the architecture of your building. There are no one size fits all solutions.

Another common mistake which will cause frost to collect in the attic is inadequate insulation. Most buildings with steep slope roofing assemblies built before the 1980’s are severely under insulated. Another problem with insulation is improper installation often blocking the attic intake ventilation, or uneven gaps and uneven layers in the insulation allow thermal transfer into the attic. Hot air holds moisture and when that heat migrates into your attic so does the moisture.

Understanding Liquid Applied Roofing Systems

Understanding Liquid Applied Roofing Systems

Liquid applied roofing systems include coatings, however a properly designed and installed liquid applied roofing system goes far beyond a simple roof coating system. The goal of this article is to help you understand liquid applied roofing systems.

There are several different liquid applied roofing systems depending on your needs and budget. These systems can sometimes cost less than traditional roof replacement.

  1. Patch and coat
  2. Seam Restoration
  3. Multi Coat application
  4. Fully-Reinforced built up Elastomeric roofing system

A patch and coat revitalizes a worn out old alphalt roof systems and can potentially add years to the roof when properly maintained. First, the entire roof surface is inspected including the seams and penetrations and repairs are made with similar materials to fix any problems you may have. Then your roof receives an application of highly reflective white or silver coating over the entire surface. The coating is primarily a UV protection, like sunscreen, however will also fill minor surface cracks and revitalizes the existing roof membrane. This is especially important on aged asphalt based roofing systems.

A seam Restoration is highly recommended on a single ply roof system. Single ply, especially epdm roofs, will almost always fail at the seams first. The membrane its’ self will typically last a life time. By cleaning the seams and patching with butyl tape then coating the seams we can bring the roof back to a like new condition, and with the addition of an optional complete coating we can possibly lower your energy bills vs a black EPDM rubber roof.

A multi coat roof application is the first level of warranted roof restoration. Yes we will warrant your entire roof against leaks even if we didn’t install it. A multi coat application is actually the installation of a complete liquid applied roofing system over the existing roofing system.

Typically this is a great option for a roof which is in decent condition overall but just beginning to have some leak issues. The multi coat application would first consist with repairing any problem areas restoring any roof seams, essentially combining the patch and coat and the seam restoration. However we will then add an additional application of liquid elastomeric for double coverage.

This multiple coatings of elastomeric, typically white but colors are available, cures to a monolithic and seamless roof membrane fully adhered to your existing membrane. This seamless membrane cures thick and durable and provides a very lightweight roof covering which we guarantee against leaks.

A multi coat roof application is a great option, when a tear off is required by code but cost prohibitive. Why replace the roof if you don’t have to? Code allows for liquid applied restoration systems no matter how many roofs you have existing. (Note: Most cities and municipalities in and around the Chicago area only allow for a maximum of 2 roofing layers.)

A fully reinforced built up elastomeric roof system first starts with a bonding resin after any major repairs are made to the roof system. This bonding resin is imbedded and with a polyester fabric which is fully saturated with the resin and adds stability to the roof. We would then apply the multi coat roof application once the bonding resin has had a chance to cure.

This entire fully reinforced roof system cures to a monolithic membrane approximately 38 mils thick, almost the same thickness as a new single ply roof system but with no seams and much more cost effective than a new single ply roof. The fully reinforced system is eligible for a lifetime-renewable warranty.
adurel fully reinforced elastomeric roof system

The multi-coat and the fully-reinforced roof systems do not count as an additional layer of roofing according to current building codes and are are excellent alternative when tearing off the existing roof just isn’t within your budget but you need a new roof. Most municipalities and cities in and around the Chicago area only allow a maximum of two traditional roofing layers. A roof restoration keeps the water out and will not become a code violation!

Since coatings are not considered roof systems, they are also not considered to be capitol investments and therefore may be depreciable 100% in the first year as maintenance (contact your accountant about this). This is a huge tax incentive, vs. amortizing the roof over a 29 year period of time as is the policy with traditional roofing systems.
US Energy Star, $500 tax write off     The roof coatings we apply consist of simple fibered or non fibered aluminum silver coat. We can also install acrylic elastomerics on roofs with good pitch or install solvent or urethane based elastomerics on roofs with very low slope or minimal standing water. Many of these coatings are energy star rated and you might qualify for tax benefits and or local grants for cool roof applications. Contact us for more information.

These applications are great over traditional roof systems like modified bitumen, smooth built up asphalt, and single ply roof systems. The multi-coat application is also a very affordable great way to bring metal roof systems back to life. Similiar coating solutions have been utilized on commercial and residential buildings going back to the 1970’s.

Not every roof is the right candidate to receive a coating system. Some things we need to watch out for include very degraded existing membrane or excesive trapped moisure within the roof assembly. In these cases roof removal is likely necessary and the installation of traditional roofing systems such as single ply (TPO or EPDM) and modified bitumen. (See also: Low Slope Roofing Options)

Low Slope Roofing Options

Low Slope Roofing Options

Traditional flat roofing systems include built up, modified bitumen and single ply. Another option gaining market share for their economic benefits are Liquid Applied Roofing Systems (See also: Understanding Liquid Applied Roofing Systems). It is important to note that the information on this page can vary from one manufacturer to the next and may change from time to time.

Low slope roofing is rated anywhere from 10-30 years by the various product manufacturers. The determination of this longevity is how the new roof is installed. One thing is for sure, though, a low slope roofing system is all about the details. Neglect one detail and it’ll leak for sure!

Single Ply – TPO Low Slope Roofing Options

TPO is short for Thermo-Plastic Olephine and is quickly becoming the standard for low slope roofing applications in the Chicago and Northern Illinois area. TPO is a highly reflective and durable single ply membrane. What makes TPO great is its’ ease of installation and it’s heat welded seams.

Hot air, forced from electric heaters, are used to fuse flashings and seams. In addition TPO is available in rolls larger than more traditional roofing systems meaning less seams. Less seams means less chance for failure. TPO is and excellent choice where minor ponding water may exist due to it’s excellent lack of water permeability.

While TPO is available in multiple colors, it’s most common is white. A White TPO roof is a highly reflective and is a cool roof, exceeding current energy efficiency standards and is an US Department of Energy, Energy Star rated roofing system. TPO may qualify for tax credits and LEED points. TPO is truly a “green roof”.

TPO is commonly installed mechanically fastened or fully adhered. Due to its’ lightweight nature it can often times be installed over existing roofing systems (when code allows). TPO is available in thickness ranging from 45 mils up to 80 mills. As you can imagine the thicker TPO will be more durable, last longer, is able to be warranted for longer terms, but also does require more up front investment.

Single Ply – PVC Low Slope Roofing Options

Single ply PVC membrane is similar in appearance to TPO. However PVC has been on the market longer than TPO. The methods and manner in which a PVC membrane is installed is very similar to that of the TPO roof described above.

A PVC roofing system requires a slightly greater upfront investment than that of a TPO roof. However the roof installation is almost exactly the same. If you want the very best thermoplastic roofing system installed, with the peace of mind that comes with heat welded seams, choose a PVC roofing system. PVC is highly chemical resistant and has a longer proven track record.

Single Ply – EPDM Low Slope Roofing Options

EPDM is similar to TPO in the fact that it is a single ply membrane, however EPDM is a rubber compound instead of plastic, like TPO. EPDM has a strong reputation for durability. With properly taped seams and detailed flashings, an EPDM roof can easily last 30 years. However, unlike TPO, the seams are treated with adhesive making them vulnerable over the long term and may require maintenance sooner than a heat welded seam.

EPDM is commonly installed fully adhered or ballasted. However EPDM can also be installed mechanically attached. Ballasted EPDM roofs are very economical on large projects, when the structure can support the weight of the ballast material, typical washed river rock.

EPDM is available both reinforced with polyester scrim and non-reinforced in thicknesses ranging from 45 to 90 mills. 90 mill EPDM is the only EPDM membrane eligible for a 30 year system rating.

Definitions of Single Ply installation methods:

Fully adhered – a roofing membrane or a component of that system that is glued in place or otherwise secured with adhesives. Membranes may also be adhered using adhesives pre-applied at the factory. Fully Adhered roofs carry system ratings of 15-20 years (30 years on EPDM with proper design and construction of the roofing assembly).

Mechanically fastened – a roofing system or a component of that system that is secured in place using fasteners of some kind. Often these fasteners are button head nails or screws with plates. Regular shingle style roofing nails are not acceptable. Mechanically fastened roofs carry system ratings of 10-20 years.

Ballasted – a roofing system that is not fastened nor adhered in place. Instead the roof is weighted in place by the application of washed river rock, manufactured concrete pavers or other media of substantial weight. Ballasted single ply roofs carry system ratings of 10 years.
Mill Thickness can be translated into inches for better understanding. Since 1 mil = 0.001″ (or 1/1000 of an inch; hence it being called a “mil”), 45 mils = .045″. In fractions a 45 mill membrane would equal approximately 1/22″.

Modified Bitumen Low Slope Roofing Options

Modified bitumen is perhaps the most common of residential low slope roofing systems. However Modified bitumen has lost a tremendous amount of market share in Commercial and Industrial roofing projects.  Modified Bitumen is still often used in some Institutional (Schools and Government buildings) roofing projects.  Modified bitumen is installed in 3′ rolls, either torch applied using flame heat to weld the cap sheet to the base sheet(s) or self adhering using factory applied adhesives on the various components. Modifiued Bitumen can also be applied with cold process adhesives applied in the field.  The duration of your warranty term on modified bitumen is determined by the quantity and type of layers.

Quick specs for a typical modified bitumen roof assembly is as follows:

  • 1 layer felt or fiberglass base and 1 layer of smooth black modified bitumen – 10 year system rating.
  • 1 or 2 layers of felt or fiberglass base with 1 layer of smooth modified bitumen and an application of an approved reflective coating – 12 year system rating. (Please note that this reflective coating may require periodic maintenance or re-application to achieve a 12 year life cycle)
  • 2 layers of base with 1 layer of granulated modified bitumen – 15 year system rating.
  • 1 or 2 layers of felt or fiberglass base with a smooth modified bitumen mid-ply and a granulated modified bitumen cap sheet – 20 year system rating.
  • 1 layer of premium self adhering base with a granulated cap sheet – 20 year system rating.

People often wonder why their modified bitumen roofs last only 10 or 12 years and do not understand that is usually the system specification provided when hiring their contractor.

A note about modified bitumen in regards to city of Chicago energy and reflectivity codes; A smooth black modified and many granulated modified bitumen membranes will not meet current city of Chicago reflectivity requirements without the application of reflective coatings.

Selecting your Low Slope Roofing System Options

Choosing a roofing system for your property may be overwhelming if you don’t know the pro’s and con’s of each membrane. There are no one size fits all solutions. Each low slope roofing membrane may be superior for some conditions, while inferior for others. The determination of this longevity is how the new roof is designed and installed. For example a mechanically attached 45 mil single ply roofing system may be rated to last 15 years, while a fully adhered 60 mil roofing system with proper insulation may be rated to last 20 and 90 mil membrane may be warran ted up to 30 years.
Liquid Applied Roofing Systems (Coatings)

To learn more about liquid applied roofing systems please see also: Understanding Liquid Applied Roofing Systems. Liquid applied roofing systems are a wonderful alternative when removal of the existing roofing system isn’t necessary or won’t fit in the budget. Liquid applied roofing systems can be expected to last 5-15 years.