Roofing Assessment Steps
 

Article: No. RAS-KB-2-14.1

 

Summary:  This article we will review guidelines for assembling roofing assessment inspections. This article can be used when considering the type of information that will be collected and presented in a roof assessment report.  


Please refer to the building authority directly for confirmation for any roofing assessment, compliance requirement required by local building codes. For the procedures and requirements, you can refer to RCI to their published training guides. A description of RCI: The professional organization for roofing consultants is RCI.  "RCI, Incorporated is an international association of professional consultants, architects, and engineers who specialize in the specification and design of roofing, waterproofing and exterior wall systems."


The Author can be reached by e-mail for questions concerning content or the opinions expressed in this article. Please use the Article number for reference.

 

Site Information


 Start with the address and any known historical site information to prepare reference information that can be included in the assessment report.  If the roof assessment begins with roof observations without any site information; site conditions; wind zones, exposures based on building location, important information will be missing from data that should be retained and linked to roof performance and premature failures.   

 

Facility Information


Prior to documenting roof construction, establish the commercial building type, use, age, construction, structural frame, façade type, construction, number of stories.  Since, in situ information rarely changes building owners should maintain electronic facility information for assessment firms, with any established local code, as documents and construction standards, to accompany the assessment scope of work.

 

How to divide Roofing Areas into Roof Sections


A roof section is a unique section of roofing that has the same construction assembly from; the structural deck type, insulation, attachments, and primary roofing materials including surfacing. Roof section boundaries are identified by edge details and termination points; e.g. expansion joints, parapet wall, or an exterior wall termination.  On large open sections, raised expansion joints; can be used to separate large areas into smaller sections.


In cases where individual floor areas are below, as in retail shopping centers, property owners may wish to identify roofing areas above the retail space for assignment of leaks and mechanical equipment service call to that space.  Special identifiers may be used if  there is no termination point that corresponds to the retail space below. For roofing sections separated without physical termination points, the roof section separation would require a detailed roof map and duplicating the documentation.  Identify slopes, drainage and mark any area where water ponds on a roof map.

 

Roofing data to be collected


Once you have the site and facility information documented and logged into your roofing database, you can proceed to identify the roofing sections that will be documented.  When using a roofing database, naming and or numbering each roof section helps keep data and documents organized.  For organizations with large roofing inventories consistent naming standards allow for quick database searches even with hundreds of roofing areas.


Moving to the site, when the roofing observations have been scheduled, the objectives should the information to be collected on the roof; where an initial observation may require destructive core cuts, moisture surveys, to confirm the assembly construction and condition, a reoccurring assessment may be able to reuse most of the previously established as built data, updating the condition of areas previously checked.

 

Roof Assessment Milestones


The data collection procedure for providing a comprehensive Roof Assessment should include the following:

 

  1. As built data collection
    • Roof Summary Information
    • Roof System Construction
    • Installed Roof Top Equipment
    • Roof Top Details
    • Observed Defects
  2. Condition Assessment
    • Moisture Survey
    • Assessed Service Life Remaining ( ASLR)
    • 1-100 Roof Condition Index Rating
  3. Documentation
    • Inspection History
    • Warranty Documents

 

Roof Summary


A basic flaw in many assessment projects is using unstructured data for as built descriptions and observed defects.  Relying on industry slang, for roofing materials; BUR, Modified, will leave documentation gaps in data collected.  Starting with roof summary information, the roofing system should be identified using its Construction Specifications Institute, master format classification.  The CSI master format (MF) is an accepted product identifier for roofing types. Commonly used for new construction documents MF improves assessment records by using the MF naming standards for the type of roofing with a 6 digit corresponding reference number.  


Reference “How to inventory Commercial Roofing Types”

 


Modified Bituminous

07 52 00

( AP) Modified Bituminous Membrane Roofing

07 52 13

( SBS) Modified Bituminous Membrane Roofing

07 52 19

Self-Adhering Modified Bituminous Membrane Roofing

07 52 19

 

Sample:  CSI Numbering use of Modified Bituminous roofing systems where there is a general group noted by 07 52 00 and specific types under this category e.g. (AP)   07 52 13. Leading roof management software has integrated CSI into the data entry design allowing users easy access to MF titles and numbering.

 

Establish the expected service life 1-50 years. This expected service life is the number of years of service that the roofing system will provide to the building.  Starting with the installation year, the years remaining are based on expected service life.  If you have historical data, for similar systems in your inventory, use a known number for projected service life Vs the projected service life based on manufacturer’s representative projections.  Often when no historical information is available, a starting point could be based in part on warranty coverage when the warranty performance is >10 years.

 

Roof System


As built roofing system construction should be documented. Identify the roofing system, noting all components and their attachments to the roof deck. 


This step usually requires core cutting the roofing system to visually confirm the components of the roofing system. If moisture is present, note the location and extent of the moisture should be documented on a roof map (see Moisture Survey)


Confirm the deck condition, noting signs of deterioration that warrants further inspection by a registered engineer. Consult local building codes for applicable structural live and dead load capacities.  Document initial system layers and subsequent layers, noting attachment and any out of spec installations, condition observations for repair or if the system should be scheduled for replacement.  This summary is not intended to cover all the potential steps a registered roof consultant may use, only a guideline to the types of information that is observed and documented. 


As the observation progresses refer to the data guidelines similar to the as built guidelines presented in  “ Introduction to Roof Asset Management”. 

 

Roof Top Equipment

                                                 

1. Equipment Type

Equipment description.

2. Flashing Description

A description of the terminating points; curb, mounts, projections, pitch pockets.                                     

3. Flashing membrane

Description of the flashing membrane (if applicable).

4. Flashing metal

Description of the flashing metal (if applicable).

5. Photo

Photo shows equipment placement, attachment detail and flashing

6. Details and conditions

Details and condition information for each roof top detail that should be documented.

 

 

 

 

 

 

 

Roof Top Details

                                                 

1. Detail Type

Perimeter, drain, projection, or equipment.

2. Description

A description of the terminating item such as parapet wall, projection, gravel stop, pitch pocket.                                     

3. Flashing membrane

Description of the flashing membrane (if applicable).

4. Flashing metal

Description of the flashing metal (if applicable).

5. Photo

Photo shows construction detail and flashing

6. Details and conditions

Details and condition information for each roof top detail that should be documented.

 

 

 

 

 

 

 

Defects

 

1. Type of Defect

Defect type (e.g. seams, tears, loose flashings, bare felts, splits).

2. Severity

Severity rating (Minor, Moderate, Major)

3. Quantity

The quantity of this defect type

4. Status

Outstanding if this defect has yet to be repaired.

5. Photo

Photo (s) shows the defect.

6. Details and Condition

A  description of the type, cause, size,  additional details

 

 

 

 

 

 

Condition Assessment


The roof observer during the evaluation of the roofing system has multiple disciplines that may be relied on check the systems condition.  Please refer to RCI, ASTM publications for specific procedures for determining roof, system component attachments, and moisture levels in installations.


During the course of checking the roofing systems, the system’s type will guide the observer in looking for out of spec items, e.g. loose attachment points, protruding fasteners, open seams.  Each roofing system type will be unique for the potential observed defects, and remediation recommendations.  Use the database to maintain consistent listings of defects by system type to identify any trends in failure points, as each system will be different depending on material type, assemblies of insulation, vapor barriers etc.


For condition, the observer can establish the observed condition and or service life remaining. 
For assessed service life remaining (ASLR) use Condition Indexing in the database to track the observed condition and the professional’s assessment of the number of years remaining. The database will adjust RCI ratings based on system settings for expected service life.  ASLR is a manual adjustment to the automatic calculations; allowing for a professional in the field observing all aspects of the roofing system performance to add or subtract years from the system calculation.


A number rating of 1-100 can be used for generating a condition rating from the initial installation to end of life. Use the software calculation to generate the initial rating based on the expected service life.   By considering these factors a more objective RCI can be assigned with some level of consistency. The RCI rating system is not intended to classify a roof as “good” or “bad”, but rather to determine roof action by a response category that is required to maintain the integrity of the roof in a cost effective manner. In so doing, the roof condition can be reasonably estimated by the person doing the roof evaluation.
These response categories and the numeric RCI range along with the corresponding database  are shown below.

 

Roof Service Life

 

  1. 86 to 100 Excellent
  2. 71 to 85 Maintenance and Repairs Very Good
  3. 56 to 70 Maintenance and Repairs Good
  4. 41 to 55 Maintenance and Repairs Fair
  5. 26 to 40 Replacement Poor
  6. 11 to 25 Replacement Urgent
  7. 0 to 10 Replacement Critical

 

These categories and the associated RCI ratings are based on studies conducted by U. S. Army Construction Engineering Research Laboratory (USACERL). From the field data collected, they were able to develop roof deterioration curves that supported their findings. Systems deteriorate slowly for the beginning years and rapidly during the latter years of service life. If properly designed, installed and maintained roofing systems can provide a high level of performance for the majority of the expected service life. There is a point, however, when the roof system reaches the end of its design/service life and will need to be replaced. USACERL suggests that an RCI rating of 40 or lower will place a roof system in the replacement category.

 


Statistical information generated by the database is the most accurate predictor of roofing systems ROI and life cycle costs when information is collected accurately.  Building statistically significant data allow building managers opportunities to spot underperforming systems relative to other roofing type groups.

 

Documentation


An important tracking area for each roof system is to maintain documents and histories for reference.  Use the warranty tracking area in the database to add the warranty information, issued by, warranty number, issued date, expiry date. A PDF of this document should be in the database for reference for documenting any mandatory inspections. A calendar of the required inspections should be maintained in the task manager for.


All inspections, where observations were made should be listed by the name the firm and the inspector who made the observations, a list of the observed defects and his/her recommendations.  Often the building manager may refer to the past observations find open work items that can be added to a service request.


The process of building an accurate Roofing Assessment report requires a trained roof observer with experience with the roofing system being assessed.  With due diligence, the observer should complete R&D of site and building history; organize records using an industry standard for identifying materials and systems in a professional database to record accurate  assessment data.


Audience:   Building Owners, Property Managers, Facility Managers, V.P. Construction, Director of Building and Grounds, School Boards, Town Managers, Condo Construction Committees.

 


Article:   This article is being reviewed by our technical writing staff and will be updated when complete.

 

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