Routine Roof Inspections

July 28th, 2010

I would like to offer some general direction to help building owners and facility managers perform routine roof inspections.  Please call a professional if you are not comfortable accessing and walking your roof.

Common issues to look for on your roofs:

Built-Up Roofs

  • Loss of felt surfacing, gravel, aluminum coating, or asphalt surfacing
  • Felt erosion, loss of plies
  • Membrane aging, alligatoring, and brittleness
  • Membrane damage, punctures, or cuts
  • Membrane defects, blisters (especially broken blisters), splits, ridges.  Blisters are spongy spots that are a result of moisture trapped between the felt plies, which can shorten the life of the roof membrane.
  • Flashings aging, splits, open laps, or slippage
  • Poorly sealed flashing terminations
  • Under-filled pitch pans at penetrations
  • Clogged or restricted drainage
  • Debris, sharp objects on roof
  • Chemical exhaust, particularly oil and solvents
  • Collapsed, wet, or damaged roof insulation
  • Insufficient fastening of sheet metal copings, gravel stops, counter flashings
  • Vegetation growth on roof due to ponding of water and dirt accumulation on roof

Modified Bitumen Roofs

  • Blisters, especially at laps
  • Loss of surfacing, especially SBS (a rubberized modifier) modified bitumen membranes
  • Open laps
  • End lap shrinkage (loss of overlap at roll ends)
  • Membrane aging, surface crazing, pitting
  • Membrane damage, punctures, or cuts
  • Flashing defects, blisters, open laps, slippage

Single-Ply Membrane Roofs

  • Membrane damage, punctures, cuts
  • Inadequate attachment, ballast, or membrane displacement, shrinkage or wind damage
  • Membrane aging, crazing, stiffening, or brittleness
  • Flashing defects, open laps, loss of attachment
  • Under-filled pitch pans or deterioration and cracking of pitch/sealant in pans
  • Clogged/blocked or restricted drainage
  • Debris, tools, scrap materials, and sharp objects left on roof by repair technicians
  • Chemical exhaust, particularly oil and solvents
  • Collapsed, wet, or damaged roof insulation
  • Insufficient fastening of sheet metal copings, gravel stops, counter flashings
  • Poorly sealed flashing terminations and loose termination bars
  • Check for tenting of base flashings due to membrane shrinkage
  • White, high-albedo roofing systems must be washed regularly to maintain their ability to reflect heat from the sun.  A dirty roof will not operate as designed

Shingle Roofs

  • Splits in shingles
  • Shingle cupping/curling
  • Loose/missing shingles due to blow off
  • Improper attic ventilation (causing cooking of shingles)
  • Exposed fasteners that are not caulked/sealed
  • Loose ridge vents due to improper nailing (nails too short)
  • Hail or other physical damage to shingles
  • Loss of gravel surfacing on shingles
  • Moss/fungus growth on shingles
  • Clogged gutters causing rot of decking near perimeters of roof
  • Kick-out flashing missing where lower elevation roofs intersect walls
  • Excessive layers of previously installed shingles
  • Improperly sized crickets at chimneys or mechanical penetrations

Concrete or Clay Tile Roofs

  • Tiles are installed with a 3″ headlap, or 2″ headlap over a sealed 30/90 hot mopped system with mechanical attachments through a strip of asphalt roof cement placed at the nail line.  Less than 3″ headlap should occur over no more than 20% of the roof.
  • Cracked or broken tiles must not be installed or allowed to remain on the roof.  Repairs made with concrete or clay tile roof adhesives are acceptable.
  • Tiles should be installed to permit thermal expansion.  Tiles at valleys should be trimmed at an angle to prevent irregular pressure at corners.
  • Headwalls, hips, and ridges of high-profile tile should be fitted with a weather blocking material such as coated polyurethane foam, mortar, mastic with felt paper, lead, aluminum, or UV-resistant neoprene, plastic, metal, or pressure-sensitive adhesive-backed tape.

All Roof Types

  • Trees need to be trimmed clear of building roof lines to prevent branches from contacting the roofs.  Some trees may need to be removed.
  • Beware of cell phone company equipment that has been installed since the roof was last replaced.  We have seen improperly supported equipment hung on rooftop penthouses or stair tower brick walls that were causing damage to the walls, improper flashing around steel pipe supports, and possible structural concerns about the weight of the equipment.  Generally, the cell phone companies take little or no care of the roof around their equipment.  If a facility is considering letting cell phone or cable companies use their roof, they should seek protection in the contract.

zumBrunnen has found that it is practical to budget a capital expense on a 5-year cycle for roofing system tune-ups, minor repairs, and maintenance.  We generally recommend budgeting between $0.05 and $0.15 per gross square foot of roof surface.  Routine roof inspections by a qualified roofing contractor and associated minor repairs and tune-ups will extend the lifetime of your roofing system and help avoid system failure.

Tom Maher

Senior Project Manager

zumBrunnen

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Fiber Cement Siding – Part 2

June 9th, 2010

I returned to the construction site located in the Northeast in May and made a closer inspection of the fiber cement siding installation.  During my first visit, I observed various installation issues, which have not been corrected, and therefore, noted again during this visit:

  • Unpainted plank ends
  • Warping and rippling of planks (Photo 1)
  • 1/8” gap not provided at terminations (Photo 2)
  • Overdriven nails on panels
  • Face nails (Photo 3)
  • Misaligned butt joints (Photo 3)
  • Uneven laps

During the Owner/Architect/Contractor (OAC) meeting, I passed around the photos, which the general contractor printed, and discussed the issues with the team.  We decided to withhold payment to the siding subcontractor for the work done that month.  Fortunately, a representative from the manufacturer was scheduled to visit the following day.  I was not able to attend, but the team dialed me into the meeting the following day, after they walked through the issues.

The team identified additional issues during their walk-through including loose clapboards.

I requested that the installer provide an independent inspector to follow the installer’s rework team, using a lift where necessary, to inspect and approve or reject the work throughout the site.  The team listened to the manufacturer’s representative state that from their viewpoint, most of the existing problems would stand in the way of providing a material warranty as currently installed.  However, the representative reports some of the manufacturer’s written instructions that were not followed are described as “best practices,” and that they were not necessary for a material warranty.  It is noted the manufacturer’s material warranty does not pay for reinstallation labor cost.  However, we pointed out that the contract documents require the contractor to install the “materials according the written instructions,” and that anything less was considered as non-compliant work, regardless of the material warranty requirements.

The manufacturer’s position to not stand behind all of their written instructions as a material warranty requirement has allowed the contractor to debate what the written requirements are.  It is my conclusion the Owner’s position is weakened and he may be forced to negotiate the definition of compliant work, and ultimately what considerations and corrections will be made.  This could include acceptance of some current work that does not comply with what the manufacture reports as “best practice.” If the Owner elects to accept some of the work as currently installed, hopefully he can negotiate considerations such as extended installation warranties and/or possibly a cost credit change order.

According to our meeting minutes, the manufacturer’s representative responded to the issues with the following comments:

  • Loose clapboards –the loose planks must be addressed
  • Unpainted plank ends –cut ends need to be either painted or treated with caulking. The manufacturer’s written instructions call for painted ends.  It is my opinion a bead of caulk is substandard to painted ends.  Some of these caulked joints will fail and these unpainted planks will then be  exposed to wind driven rain and ice, and can deteriorate from the moisture. If this occurs and causes material damage, I would expect the manufacture will void his warranty.
  • 1/8” gap not provided – the 1/8” gap is not a requirement for the material warranty but a best practice.  This comment is contrary to manufacturer’s written instructions.  Personally, I am concerned that if gaps are not provided, thermal expansion will contribute to the warping and rippling that we have observed around the site. If this occurs and causes material damage, I would expect the manufacture will void his warranty.
  • Overdriven nails and face nails on – this issue is remains unresolved and an answer is forthcoming.
  • Warping and rippling of planks – this issue is remains unresolved and an answer is forthcoming
  • Uneven laps – this issue is remains unresolved and an answer is forthcoming
  • Misaligned butt joints – this issue is remains unresolved and an answer is forthcoming

Next Steps:

The manufacturer’s representative will forward warranty information to the team that provides coverage for two times the retail value of the materials.  However, this does nothing to protect or compensate the Owner for potential issues and expenses resulting from an improperly installed system.  In the event there is a material warranty claim, it certainly helps the Owner defer labor costs but this is not the anticipated problem. The problem is the installation warranty from the contractor, not to mention the perceived value associated with work that to an observer is of lesser quality – work with poor “curb side” appeal.

The manufacturer’s representative is to contact his corporation and contact the team with a proposed path forward for the outstanding issues listed above; we requested that another inspection be provided by a higher ranking official.

Summary/Conclusions:

This is proving to be an interesting problem for the whole team.  The general contractor has done exemplary work on the project, with no change order requests to date.  All of the issues that the team has encountered have been corrected quickly by the contractor until this siding issue.

My advice to anyone interested in using fiber cement siding is to get a copy of the manufacturer’s written instructions from their website, and require that the contractor follow the instructions to the letter.

It is critical that the materials be stored in accordance with the manufacturer’s written instructions.  I have read of instances where a manufacture has not warranted an installation because the materials were found to be improperly stored.  It is also a good practice to get a list of approved installers from the manufacture.

In Part 3 of this posting, I will report on the solutions that will be put in place to correct the siding.  Please feel free comment on the blog.

Tom Maher

zumBrunnen, Inc.

Atlanta, GA

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Fiber Cement Siding – Part 1

June 9th, 2010

I visited an apartment construction site in the Northeast in April of 2010 and found various fiber cement siding installation problems. Most of the readily apparent problems observed were related to rippling and uneven lapping of planks. For example, at 2:00 pm, the afternoon shadows cast rippled shadows on the lapped siding.  The problems on this particular wall were evident. However, in the morning, this same wall is in the shade and the problems cannot be seen as easily. These issues are showing up around the entire work site and can be observed at various times of the day.

In the Owner/Architect/Contractor meeting, I notified the team of my concerns and passed around digital photographs of the worst problems. The contractor initially was defensive, but subsequently agreed to follow up with the architect and the manufacturer’s representative; they are committed to doing an exemplary job on this project.

After the meeting, the owner reported to me that there are serious fiber cement siding deterioration problems at one of their other Northeast properties.  The problems typically occur near grade and around nails; apparently the panels are pulling nails out due to constant thermal expansion and contraction action.

Research on the Internet reveals “the many styles of fiber cement panels have slightly differing attachment techniques specified by the manufacturer.  Fiber cement siding is often blind nailed, the nails are actually hidden by the overlapping lap siding plank.”

The architect on this project complained that manufacturer’s instructions were difficult to keep up with due to ongoing changes in the products and the evolution of installation techniques.  I checked this manufacturer’s website and found that the fiber cement siding lap siding instructions were last updated in April of 2009.

A January 2010 technical support bulletin concerned with expansion characteristics of fiber cement panels provided the thermal expansion characteristics of the manufacturer’s various products and the following statements:

“It is the responsibility of the Licensed Design Professional, when using our components as part of the assembly to:

* Adhere to all the installation requirements listed in the relevant product installation instructions.

* Design a wall assembly that actively manages moisture considering both interior and exterior environments of the building, particularly in buildings that have a high risk of wind-driven rain penetration, that are artificially heated or cooled, or (that) contain indoor pools/spas.

* Understand the interaction between system components.

Please be advised the manufacturer provides a limited transferable product warranty covering the product only. The manufacturer is not responsible for system design or installation.”

These statements at first appear reasonable.  However, upon further reflection, they suggest to me the possibility of an increasing number of complaints associated with this type of product.  In my experience, project specifications and design drawings do not provide installation details, they direct the installer to adhere to the manufacturer’s instructions.   This is appropriate, even though products may appear similar, they often have unique or changing installation requirements.  Unfortunately, it is also my experience that contractors frequently fail to check for the appropriate installation requirements. Therefore, to ensure proper installation, the owner’s representative should verify that the contractor is following the correct version of the manufacturer’s requirements by contacting the manufacturer and determining which instructions are appropriate for the materials purchase for the project.  A review of construction documents, including shop drawings and material submittals prior to construction, should be conducted to ensure compliance.

There is a lot of praise on the Internet for fiber cement panel systems; I believe it is a superior product when properly stored, installed, and maintained, provided there are not inherent problems in a formula used by the manufacturer.  Judging from the growing number of complaints noted on the Internet, and those I have witnessed, installers are not always properly storing the material on the shipping pallet as required by the manufacturer, nor are they following all of the manufacturer’s installation requirements.   Additional problems can occur when subsequent contractors, such as the grading and landscape contractors, allow backfill or landscape to come in contact with the siding.  Architects may not provide adequate framing for nailing of the siding.  Owners may not properly maintain all related component’s of the building.

Beware, there are contractors who claim to be experts, but no one is an expert unless they know and adhere to the details. Should your installation go wrong, do not hesitate to call in the manufacturer’s representative to help identify and resolve the problems.  The manufacturers that I have dealt with stop short of acknowledging any flaw in the design of their product, but will be willing to point out installation shortcomings.  We also need to remember that their warranty only applies to failed product that has been properly stored, installed, and maintained.

As an update, the first representative from the manufacturer visited the site in April of 2010.  I will return to the site near the end of April, and on my next posting, will review his findings and next steps.

Tom Maher
zumBrunnen
Atlanta, GA

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The Capital Reserve Study Process

May 18th, 2010

Whether your facility is twenty plus years old or construction is nearing completion, there is a fundamental need for planning the required reserve funds for the next twenty or thirty years. I have been fortunate to work on these studies in most types of commercial and institutional buildings. For the past five years, I have been focusing on senior living and multi-family housing with zumBrunnen, Inc. located in Atlanta, GA.

My clients often pursue this question after ten to twenty years of operation. A good study will address all capital replacements that cost more than a threshold limit (often $1,000) and have a lifetime of more than one year. Often, painting is not included, but painting can extend the lifetime of a building system, so many people include it as a capital expense.

The engineer that performs the study will typically visit the site one or two times prior to submitting a draft budget report for review by the executive, CFO, and facility manager. I prefer to sleep on-site if a guest room is available. Ideally, the engineer’s time on-site is maximized.

A visit (or survey) begins with an interview with the primary people involved with the study at the facility. The interview covers basic facility information, chronic problems on the site, and wish-list items that can be included in the budget as improvements (not capital expenses). The interview should be followed by a walk-through of the major buildings. The service should include software that can be used to update the budget information and run reports. Time must be set aside in the first visit to introduce the users to the software and install it on at least one computer. Look for software-based services that you will be able to update, rather than static, hard copy reports.

The engineer will spend the next two or three days walking the entire facility, taking photos, recording information, interviewing individuals such as maintenance, food services, marketing and sales, fitness, activities, and transportation directors. The engineer may need to review drawings and specifications on-site unless the owners have sent the drawings to the engineer’s office.

Be sure to describe all of the physical problems in the facility to your engineer, even if you think the engineer will not be able to address them. This is their job. The worse the problem, the more the engineer will have to work. If they need a specialist, they should contact one. But you should insist that all of your problems be addressed in the budget and narrative report.

A good engineer will demonstrate some of the important resources that are available on the Internet. My favorites are:

http://www.dsireusa.org/ – A clearing house of all available energy-related rebates, loans, and incentives available in the US. This is kept current by the University of North Carolina. All of my clients use it.

http://www.bigtray.com/ – This is the Amazon of commercial kitchen equipment. Many of my clients have been at the mercy of their local restaurant equipment vendors for too long. They have found Bigtray to be a wonderful resource for availability and pricing. At a minimum, the pricing will help keep your local vendor honest.

http://www.usgbc.org/DisplayPage.aspx?CMSPageID=2084 – This is a list of available resources for LEED certification under the Existing Buildings: O&M program. LEED certification has advantages in reduced operating expenses and marketing. Even if certification is not being considered at this time, the operations savings techniques that are documented in these resources are worth pursuing.

Usually the engineer will send out the first draft copy of a twenty- or thirty-year budget within a week or two, for review and discussion with the executives at the facility. The report should show, in a matrix format, each cost that has been scheduled over the duration of the report. This will look like a spreadsheet. Costs should be totaled for each year of the study and for the cycle of costs for the individual item. For instance, carpet in a dining room may be scheduled for replacement every seven years during a 20-year study. Yearly costs should be totaled vertically, while item costs should be totaled horizontally.

A good engineer will provide rough budget estimates for repairs, replacements, and improvements that you may want to consider in future years, plus provide recommendations for materials or techniques that can be used to fix a problem. If your drains are failing below grade, the engineer might recommend a cured-in-place piping repair as an alternative to conventional pipe replacement. The engineer may ask a waterproofing specialist or a roofing contractor to visit your facility to prepare a proposal that will be added to the budget.

After the executives have reviewed and approved the budget reports, the engineer typically prepares the final narrative report, with exhibits and photos. A follow-up visit with additional software training and demonstration to the board of directors is a huge plus, if it can be included in the services. Some of the executives that I have worked with have asked me to meet with planning committees or architects. Some architects will focus too much on a new addition to the building, and not enough on renovation work that is needed in an existing wing. A coordination meeting can be useful for documenting the extent of renovation that is needed as part of a major capital project.

All studies should be done in accordance with ASTM E 2018-01 Standard Guide to Property Condition Assessment. This is the official baseline for reporting.

Your engineer should have twenty or more years of experience. These studies should not be a training ground for young, non-professional assessors. I recommend that you get references for the service provider, and if possible, get the resume of the engineer.

A good engineer has a well rounded and current list of training that they have been pursuing. Maybe they are LEED certified. They should have training in roofing systems, waterproofing, HVAC equipment, electrical systems, life safety code issues, masonry, paving, and other building systems. Shop around, nationally. The good ones will travel.

Thanks

Tom Maher, PE
zumBrunnen

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Converting from an R22 Split System to R410A

May 13th, 2010

Sometime within the next five years, you may find that you need to replace your HVAC split system air conditioner or heat pump. Whether you live in a single home, a condominium, or and independent living apartment, here are some of the questions that you will need to answer.

R22 refrigerant and its HFC replacement R410A are totally incompatible. Your existing condensing unit and cooling coil are not suited to the new higher pressure refrigerant. It is possible to reuse the copper tubing lineset between the two, but we will discuss that later.

The new condensing unit and coil will be physically larger than the old unit. If your condensing unit is on a midrise condominium rooftop with dozens of other condensing units, they may need to be remounted in such a way that provides the manufacturer’s recommended clearance between units. The coil will be taller than the old one, and will not fit in the metal coil enclosure at the air handling unit. This enclosure will have to be rebuilt, or you may have to buy a new air handler that provides a greater airflow required by the new coil.

Consider buying the highest efficiency model that you can afford. There is obviously a premium to pay for the most efficient models, but some level of higher efficiency may be affordable.

The conventional wisdom is that the copper lineset should always be replaced. While this is true, it is not always practical to do so. Generally, you will not save money by reusing your old lineset. It will have to be flushed with nitrogen and a solvent, then modified for reuse. The labor and materials needed to do this will equal the cost of replacing the lines. If your line routing is inaccessible (under a concrete slab) you may want to seriously consider reusing the tubing.

Not all linesets may be reused. Your contractor will perform a calculation to determine whether it is possible. Generally speaking, the coil must be within 25 to 50 feet of the condensing unit for line reuse to be possible. A larger line size will be needed beyond that distance.

If the condensing unit is close enough to the coil, the lines might be reused after flushing with nitrogen and a chemical flush such as RX11 Flush, Qwik System Flush, or Diversitech Pro Flush. Years ago, the line flush was done with R11 refrigerant. This is now banned by the EPA, so if your contractor suggests it – say no. You should also consider the age of the existing lines. You may not want to reuse 25-year-old lines, but if they are only 12 or 15 years old, it may be okay. I would always replace the lines if it is feasible. New or larger sizes may be required, in which case a new line set would need to be routed near the existing lineset. Drain and remove the old lineset.

For a good description of how to flush your lineset, visit Robert Scaringe’s article, http://contractingbusiness.com/refrigeration/cb_imp_77425

Tom Maher, PE
Atlanta, GA

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