Roof Consultant Services Can Lead To Long-Term Cost Savings

By Samuel Chiodo, RRO

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 that sometimes one has to spend money to also save it, especially with regard to a building’s roof.

Although they are the least visible part of a 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 5 to 10 years by heading off leaks and other adverse conditions, which translates into significant long-term cost savings.

Preventative investment in the 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 of each is to extend the life of the building envelope function, but the various stages require two completely different types of oversight.

New construction

Like any area of construction, from mechanical to structural engineering, roofs require a unique expertise to maximize their effectiveness. Having certified consultants specializing in each building envelope discipline during the architectural design phase, product specifications, submittals and inspections through to the final construction punch list can ensure the roof and other building envelope components are installed in accordance with local codes and manufacturer requirements to provide the facility and its contents with watertight protection.

Design review

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 in various stages. A pre-design meeting between the owner/developer, architect and roofing consultant can help highlight issues that architects may need to address or coordinate in the design and material specifications, 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 structure and materials in extreme climates. However, an architect designing in the southern climates, for example, will also need a code-approved roof design with specific attachment details for membrane or metal systems and all its components that meet the calculated wind uplift pressures required in all 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 the 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 design details coordinated with material 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 large 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 some do not. For example, sprayed polyurethane foam (SPF) and most 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 or cooling tower 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?

Product submittals

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 meeting 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.

One 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, so a roofing consultant would 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.

Pre-installation conference

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, vents, and curbs. A pre-installation conference should be a top priority to co-ordinate these efforts and ensure everyone is on the same page working together to protect the roof membrane and minimize any surface damage.

At this meeting, the roof consultant joins with the owner’s representative, architect, general contractor, roof subcontractor, roof manufacturer, and any subcontractors whose work may impact the roof to co-ordinate 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. We recommend that all roof penetrations be a minimum of 8 inches away from vertical walls, base flashings, curbs, metal roof jacks and any unit penetrations.  Difficult penetration flashing such as angle iron, Unistrut or pipe clusters penetrating out of the roof deck, base flashing areas, or next to curbs are difficult to properly flash. These penetrations can require pitch pan type flashing conditions which are not as a rule included in the manufacturer warranty.

Quality assurance inspections

After all plans, submittals, and products are approved and the actual work begins, a roof consultant should provide quality assurance inspections at various stages throughout the installation. The number of inspections can vary depending on the project. However, four is a good guideline:

● First inspection at the beginning stage to ensure proper installation startup;

● Second inspection in the middle as a progress check;

● Third inspection near the completion of the installation; and

● Fourth would be a final or punch-list inspection at the very end.

Roof inspections focus not just on the quality of work, but on the complete roofing project. This means inspectors not only review how well the roofing subcontractor installed the work; 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 remedial repairs were made and the roof surface was re-coated as required by the manufacturer.

During the roofing consultant’s inspection reports and photographic records throughout the process, it was easy to see that damages were not due to negligence on the part of the roofing contractor. As a result the general contractor had back-charged the cost of and repairing the damages, cleaning and re-coating of the roof surface to the other subcontractors. Once these conditions were met, 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.

Preventative maintenance

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 ultimately 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, not in 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. This is known as a condition survey.  Based on those results, the consultant will develop projected lifecycle budget cost estimates and establish plans for upcoming maintenance, replacement, or repair.

From this point, a good roof management program should include annual reviews, during which the inspector looks for damage, including:

● Membrane system deterioration or blistering;

● Low spots or ponding water areas;

● Unsecured/damaged flashings or coping; and

● Sealant failure at termination points.

If the roof shows signs of deterioration, the consultant may recommend moisture testing, such as:

● Electric Capacitance/Impedance Testing –– a non-destructive testing technique used to quickly and accurately identify water entry pathways and areas of entrapped water within a roof construction.  This technique is based on the ability of a material to store electrical energy. It involves placing a moisture meter on the surface of the roof to send a safe electric current into the roof without penetrating the roof membrane. If the material is wet, the dielectric properties of the material would produce a higher meter reading than it would if the material were dry.

● Roof probes –– used to check distressed areas for moisture by penetrating the roof surface with probe pins and taking readings from the moisture meter.  This would a follow-up confirming moisture readings at areas from the impedance testing;

● Infrared scans –– infrared snapshots of a roof area are taken to detect the possible presence of moisture by recording temperature differentials;

● Nuclear scans –– a roof grid survey is used to detect subsurface moisture; and

● Roof cores –– This is an optional follow-up to the above types of scanning.  An investigative core-cut is taken of the roof membrane and insulation.  These areas are patch-repaired on completion.  The core is taken to a certified testing lab and a documented engineer stamped report is generated with the results of the moisture testing.

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, RRO – is a specialist in Roof Technologies and Science with Glazing Consultants International, 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 at schiodo@glazingconsultants.com or on Twitter @glazingconsult. Find out more about GCI at http://www.glazingconsultants.com, and join our Building Envelope Matters LinkedIn group to discuss building envelope issues.