Most people have heard that one has to spend money to make money. However, in today’s uncertain economic times, companies across the country are not just looking to make money––they are also tightening their belts, battening down the hatches, and looking for ways to save. Even during these times, it is important to remember sometimes one has to spend money to also save it, especially with regard to a building’s roof.
Although they are perhaps the least visible part of the building, roofs can account for up to 50 percent of the total surface area and represent up to 25 percent of the total value. By proactively investing resources in maintaining new and existing roof performance, building owners may extend their roof’s life from 15 to 25 years by heading off leaks and other adverse conditions, which translates into significant long-term cost savings.
Preventative investment in a roof’s life can come in two primary areas; during a new building’s construction process or as a preventative maintenance program for an existing roof. The goal is to extend the life or primary envelope function, but the various stages require two completely different types of oversight.
Like any area of construction, from mechanical to structural engineering, roofs require a unique expertise to maximize their effectiveness. Having consultants specializing in each building envelope discipline during the architectural design phase, product specifications, submittals, and inspections through to final construction can ensure the roof and other building envelope components are installed to provide the facility and its contents with watertight protection.
The optimal time to get a roof expert involved in the building construction is during the design phase, while the architectural team is still working on its detailed plans. A pre-design meeting between the owner/developer, architect, and roofing expert can help highlight issues architects may need to address or coordinate in the design, especially ones unique to a particular building’s climate or exposure.
In northern climates, considerations must be made for snow weight and removal, ice dams, and the expansion and contraction associated with building materials in extreme climates. However, an architect designing in the Maritimes, for example, will also need an approved roof design with specific attachment details for the membrane/metal system and all its components that meet the calculated uplift pressure required in zones potentially affected by hurricanes. In either situation it can be helpful for an architect to have a roofing expert available to alert him or her to any potential issues before they arise.
As the design progresses, the roofing consultant should review architectural drawings and MasterFormat Division 07–Thermal and Moisture Protection specifications related to waterproofing and roofing. The goal here is twofold; to ensure the architectural team designs and specifies a system to adequately protect the building, meeting state and local codes, and to make sure the drawings and specifications are detailed and accurate enough for the general contractor to obtain correct bids from roofing subcontractors. Precise, thorough outlines—along with coordinated specifications––at this stage can prevent the need for time consuming architectural blueprint changes and costly re-bids or change orders later in the building process.
In general, the roof consultant will be looking at the design drawings and specifications for several items.
1. Membrane components and flashing: Is the specified membrane and flashing practical for the design and do the detail call-outs reflect the specification manual?
2. Termination details: Does the membrane, flashing, or metal details transition properly when intersecting with other discipline terminations?
3. Detailed attachment method: How the roof is attached is a significant factor in its longevity and effectiveness. Do the specifications and design drawings provide manufacturer related details relevant to code requirements, building exposure, and geographical location?
4. Product compatibility: Just like any construction application, some products work together and others do not. For example, sprayed polyurethane foam (SPF) and asphalt products are not compatible. In most cases, the manufacturer is required to submit verified test results. Will the specified roof system products that intersect with other subcontractor products (e.g. a glass and glazing curtain wall) all work together?
5. Sequencing of installation: Roofing system components must be installed according to manufacturer details and requirements as well as industry standards to maximize performance and effectiveness.
6. Membrane system protection: Certain access areas––such as where the HVAC units are located––will have higher foot traffic and maintenance activity. These locations require compatible protection pad installation. This should be shown in the drawings and called out in the specifications. Is there enough membrane protection in the right places?
After a roofing subcontractor has been selected, he or she must submit an approved manufacturer roof and insulation system, including all detail components and shop drawings that meet the wind uplift design pressures and code requirements. The roofing consultant should review these submittals to ensure they are in accordance with the design drawing, specifications, and contract documents.
A common mistake in many projects is an inappropriate fastener call-out (e.g. the proposed use of exposed galvanized fastener attachment for coastal area projects). However, the salt air environment will cause oxidation and rusting, causing a roofing consultant to call out his or her appropriate recommendation such as a stainless steel fastener. It is a small detail, but it can have a tremendous impact on the roof component performance and necessity for future repairs.
Many of the various subcontractors involved in a building project will require roof access at some point to install their work on the project. Some may need to penetrate the roof to install conduit pipes, support stands, roof vents, and curbs. A pre-installation conference should be a top priority to coordinate these efforts and ensure everyone is working together to protect the roof membrane and minimize any surface damage.
At this meeting, the roof consultant sits with the architect, general contractor, roof manufacturer, and any subcontractors whose work may impact the roof to coordinate schedules and plans. Such a conference can also help determine where extra roof protection may be needed.
Other issues often addressed are the spacing and separation of all roof penetrations. All pipe penetrations, vents, and curbs are spaced far enough apart from each other and the parapet walls to leave enough room for the roofers to properly flash them. Lack of proper flashing can cause leaks and may affect the roof manufacturer’s warranty.
Quality assurance inspections
After all plans, submittals, and products are approved and actual work begins, a roof consultant should provide quality assurance inspections at various points throughout the installation. The number of inspections can vary depending on the project. However, four is a good guideline to start with:
• One at the beginning to ensure the proper installation startup
• Two progress inspections as necessary
• And a punch list/final inspection at the end of the installation
Roof inspections focus not only on the quality of work, but on the complete roofing project. Inspectors not only review how well the roofing subcontractor installed the work but they also look at how other trades have treated the roof in progress.
This author knows of a condominium building where the roofing subcontractor was a reputable firm, known for quality work. The initial and mid-point inspections revealed a quality roof installation with good workmanship, industry standard terminations, and tight flashings. However, during construction, the roof system cap sheet was not protected by other trades as they performed their work and was exposed to a multitude of staging equipment and debris. Later, inspections revealed counter-flashing and base-flashing terminations had been damaged, and stucco residue had been left to harden on the field membrane. As a result of this extensive surface damage, the warranty was withheld until the roof surface was re-coated as required by the manufacturer.
Roofing consultant’s inspection reports and photographic records, throughout the process, revealed that damages were not due to negligence on the part of the roofing contractor. This resulted in the general contractor back-charging the cost of surface cleaning the roof and repairing the damages to the subcontractors. Once these were repaired, the roof manufacturer was able to provide a warranty.
The ultimate goal is a secure building envelope and to make sure the roof is watertight and in accordance with manufacturer requirements, shop drawings, industry standards, and required state and local codes.
All roofs have a limited lifespan, eventually requiring replacement, retrofit, repair, or restoration. Regardless of whether a roofing consultant was involved in the building’s construction, developing a preventative maintenance plan can further extend the roof’s life. It can also save money by correcting problems before they become major leaks, which could cause structural damage. Over time, a roof asset management program can optimize roof performance, save money, and allow for replacement or repairs on a planned basis instead of reaction to a crisis.
If a roof is new and has been examined by a roofing consultant throughout construction, the final report should provide enough information to establish a maintenance plan and inspection timetable.
For an existing roof, a consultant should thoroughly inspect it and provide a written report of findings with a photo survey of the conditions for future reference. Based on those results, the consultant will develop projected lifecycle budget cost estimates and establish plans for upcoming maintenance, replacement, or repair.
A good roof management program should include annual reviews, during which the inspector looks for system failure or deficiencies. If a roof shows signs of deterioration, the consultant may recommend moisture testing to detect subsurface wet insulation or system components. Testing is followed up with professional engineering stamped report analysis.
A penny saved is a penny earned
Ultimately, the goal of both new construction roofing review and ongoing management programs is to protect the interest of the building owners, extend the roof’s life, and prevent costly leaks and damage. In today’s business climate, many building owners and businesses are understandably looking for ways to cut costs. However, involving a roofing consultant in the initial design or an ongoing maintenance program can end up saving the company more than it spends.
Samuel Chiodo is a specialist in Roof Technologies and Science with GCI Consultants, LLC, a building envelope consulting firm. He has worked in the roofing industry for more than 20 years and is a member of RCI Inc. Chiodo can be reached via e-mail at firstname.lastname@example.org.