Made to Move: Single ply roofing systems provide strong defense against leaks

By Dana Howell

Damschroder Roofing LLC

This article is reprinted with permission from Properties Magazine.

Does your building have a flat roof that has been a constant problem? Do you find yourself making what seems to be never ending repairs to your flat roof? Are you convinced that there is no flat roof out there that doesn’t leak? Do you find yourself asking the question why would anyone construct a building with a flat roof? All these questions/concerns are legitimate flat roof questions.

Let’s start at the beginning. Why would you build a structure with a flat roof? There are actually many reasons, but the main reason is space. A flat roof supported by columns gives you a much larger floor plan, typically seen in banquet halls, strip malls and warehouses.

Now we understand one reason these structures are built, but what causes them to be a constant problem keeping them from leaking? Again, there are many factors, but at this time I would like to focus on just one: movement. Any time you have temperatures that fluctuate as they do in the Midwest, you will experience movement. With this being said, if your flat roof is not able to withstand movement you experience failure. This is why splitting and cracking can often be seen.

A great solution to this problem was the invention of single ply roofing. Single ply roofs are roofs that protect a building through one layer of roofing membrane as opposed to the old multi-layers of tar felt and gravel. Two popular types of single ply roofing in our region include rubber (EPDM) and roofing materials containing plastic compounds such as PVC’s (Poly Vinyl Chloride). These membranes are able to move more freely to take on the expansion and contraction often seen in large buildings.

The trend in flat roofing is clearly moving toward the single ply roofing systems over the multiple ply. Single ply roofing has been on the increase for many years while multiple ply roofs have been seeing a significant decrease in the market shard of flat roofing.

Rubber was the dominant single ply during the 1960s through the mid 1980s. Rubber is installed several different ways. Some are installed by overlapping the sheets of rubber and covering them with river rock called ballast. Others are glued or screwed to the deck. The seams are then glued together with the hope of providing a long lasting water proofing solution. The major problem associated with rubber roofs is de-lamination. De-lamination is the breaking down of the glue or adhesive that holds the sheets of rubber together.

Heat welded roofs are made of plastic compounds such as PVC. Heat welded roofing systems are the fastest growing portion of the single ply roofing industry. The welding together of PVC sheets at the seams provides a permanent and stronger bond than glues or tapes. The Duro-last Corporation in Saginaw, Michigan actually pre-welds sheets of membrane up to 2,500 square feet in their factory, thus most of the seams of a deck sheet are welded under ideal conditions.

For more information, call Damschroder Roofing LLC at 888-307-2785 or visit www.damschroderroofing.com.

How to Find a Reputable Roofing Contractor

The answer may not be as hard as you think. Here are a few possibilities to consider:

  1. Check the telephone directory’s yellow pages. Browse the “roofing” section for the names of local people you can call for an estimate. Sometimes the ads will have specific information about the person, such as location, hours of operation, whether they accept credit card payments, and whether they provide free estimates. Call two or three contractors, so you can have a better chance to hire the right contractor for the job.
  2. Contact the Better Business Bureau. While this organization will not provide a list of names for you to call, it can give you an indication of someone’s response to complaints so that you get an idea of his or her character and reputation.
  3. Contact local roofer-related organizations. There may be roofer or construction groups in your area that can tell you what to look for in a roofing contractor, and perhaps recommend a few names.
  4. Ask building supply stores. Often they keep a list of roofers they recommend to pass along to people who are looking for consulting or hands-on help with building projects.
  5. Building companies and roofing contractors increasingly have a web presence. A good contractor web site will have photos of projects they’ve done as well as testimonials from satisfied customers.
  6. Ask for referrals. Wherever you get the name of a possible roofer for your project, follow up by contacting his references. You may even want to take a glance at the contractor’s workmanship on previous projects, if the building owner will allow access to the roof.
  7. Pay in portions. Never pay in full for a roofing job before completion of the project. You can pay a portion if you really want to, but agree to this with the contractor up front.

According to the National Roofing Contractors Association most rooftop problems are caused by installation workmanship, not material failure. Your roofing system is certainly the most critical part of your building when it comes to watertight protection, and you should make sure to hire a contractor who can be trusted to install the system correctly and stand behind their work.

Fall Hazard Control: Part 1

The construction industry has historically addressed safety concerns primarily as a behavioral issue, with each stage of a project determining the specific hazards that might be encountered during that stage. For example, the construction phase of a facilities life cycle would typically have different workers and hazards than the operations phase, etc. As facility owners become more aware of the soaring cost of workplace injuries and are held more accountable for all phases of a project life cycle, enlightened organizations are acknowledging that certain hazards are indeed present throughout all phases of a project or facilities life cycle.

“Constructability” is a project management technique that reviews a project’s processes from start to finish, during the pre-construction phase. As the chart shows, the cumulative value of constructability (the curved line) increases over time, particularly during the latter stages of a building’s O&M phase and renovation phase.

Fall hazard control is increasingly recognized as uniquely able to prevent significant potential injury cost. When implemented and planned into the design of facilities as part of a constructability analysis, it will spread its value across all phases of a building’s life cycle.

A core concept in the use of constructability to address fall hazard control is an understanding of the hierarchy of preference of controls. This refers to the overall value and effectiveness of the three types of fall hazard control: elimination, prevention, and protection from the effects of a fall.

Here are a couple of examples of how fall hazard control might be included in a constructability analysis:

  • The installation of strategically-placed fixed anchorage points (that can be used for both fall prevention and fall protection) can reduce costs throughout ALL phases of a building’s life cycle.
  • Properly designed parapet walls (minimally 39 inches in height and enclosing the entire rooftop) is ultimately the most effective way of reducing potential fall hazards by enabling fall prevention for all future work or equipment repairs and additions.

Over the course of the next three posts we will discuss each of the three types of fall hazard control; here is a brief overview:

Elimination

This is the first and most effective line of defense against falls from heights. To do it requires a careful assessment of the workplace and the work itself. The “who, what, when, where, why, how, and how much” of each exposure is considered. This pre-consideration of the work and site often not only leads to eliminating the hazard altogether but also identifies alternative approaches to the work that can measurably enhance productivity.

Prevention

The second line of defense and often the most realistic when fall hazards cannot be entirely eliminated, is prevention. This also requires assessment of the workplace and work process. It involves making changes to the workplace so as to preclude the need to rely on the worker’s behavior and personal protection equipment to prevent falls.

Protection

Protection from the effects of a fall is the last line of defense. It should be considered only after determining that the fall hazard cannot be eliminated or the possibility of falling prevented. This is the domain of fall protection and calls for equipment such as safety nets or harnesses, lanyards, shock absorbers, fall arresters, lifelines, and anchorage connectors.

A Sighting of Bigfoot

Recently, I have received questions about carbon content and carbon footprints associated with roofing. Before we can track down the source of those footprints we need to know what we’re searching for.

The technical definition of a carbon footprint is that it is a measure of the amount of carbon dioxide produced by a person, company, business or country over a given time. A more generic definition is that it is a measure of the impact human activities have on the environment based on the greenhouse gases produced. This second definition includes more than just carbon dioxide produced.

A primary carbon footprint considers the most direct impacts, like the use of a car or airplane. A secondary carbon footprint looks more at the entire lifecycle of activities or processes, such as with the production of a product. There are lots of theories as to how and what to measure to determine an individual carbon footprint. Numerous calculators attempt to put a numerical value to a product’s or process’ carbon footprint, but there is no single agreed-upon standard. The concept of “cap and trade” is even being debated as a means to controlling carbon footprints.

The cap and trade issue deals with controls placed on total carbon dioxide emissions. Contrary to what many people think, cap and trade is not a policy for regulating Wall Street or providing health care. A Rasmussen poll found that 76% of Americans have no clue what cap and trade means. Yet, the system, if implemented, is essentially a tax that could have broad implications for the costs of generating electricity or producing goods and services. With this scheme, carbon emissions are limited or capped and an organization is allocated an allowance for the amount it can emit. Then, companies buy and sell capacity based on whether they are emitting more or less than their quota. This could have the effect of shifting power plants from using coal, an abundant resource in the U.S., to natural gas to generate electricity.

Natural gas is the main fossil fuel source for producing ethylene used in making the vinyl chloride monomer (VCM). VCM is a key component in polyvinyl chloride (PVC or vinyl). Increases in natural gas demand will increase its price and increase costs to producers of vinyl products, including roofing and other construction components.

This is a very complex interconnected issue that is being hotly debated. There will no doubt continue to be many changes to environmental regulations in the near future. Construction specifiers are anticipating these changes and are beginning to include them in their design considerations. Construction and facility management professionals should stay informed to be able to respond appropriately.