PVC Is To Asphalt Like Oil Is To Water

When considering reroofing options for commercial facilities, it’s important to keep in mind that not all “new” roofing materials are compatible with “old” materials. Case in point: PVC membrane roofing products are not compatible with asphalt-based products. Like oil and water, like Superman and Kryptonite, like a tuxedo and brown loafers, it’s best to keep these two materials away from each other.

If you’ve made the decision to replace or re-cover your old asphalt roof with a new PVC membrane, here are some common issues that can affect the quality of your new roofing installation:

  • Tear-offs of asphalt roofs often create dust that contaminates new membrane. To avoid this problem, consider the wind direction and take steps to ensure that dust blows away from PVC materials. Use a tarp on PVC materials that are placed near the tear-off so that asphalt dust does not get on the new membrane. Develop a work plan to make sure that asphalt-contaminated shoes or boots do not get on the membrane. And complete the entire asphalt tear-off before beginning the PVC installation.
  • Make sure that proper, compatible sealants are used on the new membrane. Many caulks, sealants, and pitch pocket fillers contain asphalt, and should never be used on PVC.
  • If your project involves re-covering the built-up roof rather than tearing it off, a suitable separator must be installed between the old asphalt and new PVC roofing systems. Insulation materials such as EPS or EXPS rigid foam (whether fanfold or board – as long as it has an approved facer) and polyiso foam board work well. At a minimum, Duro-Last® requires the use of one of our polyethylene separator sheets, either the Duro-Weave™ or Duro-Blue™ product.
  • If asphalt does come into contact with the new PVC membrane, clean it immediately, because it will “bleed” into the membrane and become impossible to remove. Never use a solvent to clean asphalt off the membrane. Solvents melt the asphalt and soften the membrane, making the problem worse. Instead, use cleaners like DeWitt’s Remove-It Citrus Spray Cleaner, Simple Green®, or a non-solvent based whitewall tire cleaner.

Follow these few simple steps on your PVC roofing project to get a secure, watertight installation that even Superman would have problems pulling apart.

National Safety Month – Office Safety

This is the final post in which discuss office safety. This topic is often overlooked as office employees are not aware of all of the safety hazards that exist in their work space. There are the obvious hazards such as a slippery floor or open file drawer, but there are also not so obvious hazards such as poor lighting or poorly designed office furniture.

Below is a list of common office hazards.


One of the most common causes of office falls is tripping over an open desk or file drawer. Be sure to close drawers completely after every use, especially those located in a common work area such as a file room.

Pick up objects you or co-workers may have left on the floor and wear stable shoes with non-slip soles.

Strains and Overexertion

You may not think about strains or overexertion when working in an office, but there may be times when you need a box of computer paper. If possible use a hand cart or ask for help from another employee.

Struck By or Striking Objects

Make sure you are always looking forward when walking to avoid bumping into other people, doors, desks, file cabinets, and open drawers. Use mirrors in corners to see if anyone else is coming before turning that corner. Most importantly, pay attention to where you are walking at all times.

Caught In or Between Objects

Office workers can become injured when fingers or articles of clothing get caught in or between objects such as drawers, doors, or windows. Keep hair, articles of clothing, and jewelry away from office machines such as paper shedders.

Workstation Ergonomics

Ergonomics means fitting the workstation to the worker by modifying or redesigning the job, workstation, tool, or environment. If a desk is too low it should be raised to encourage good posture and reduce back strain. Another common oversight involves the use of computer monitors. Make sure that your monitor is away from sources of glare or direct light and position the monitor directly in front of you. Also make sure to take adequate breaks to rest your eyes and muscles. This break doesn’t necessarily mean a break from working, but it should be a break from doing that particular task.

National Safety Week – Slips, Trips, and Falls

Employee exposure to wet floors or spills and clutter can lead to slips, trips, falls, and other possible injuries. Slips, trips, and falls constitute the majority of general industry accidents. They are the number one cause of nonfatal injury, cause 15% of all accidental deaths, and are second only to motor vehicles as a cause of fatalities.

Ways you can keep your employees safe out in the field:

  • Require the use of personal fall arrest equipment.
  • Install and maintain perimeter protection.
  • Cover and secure floor openings and label floor opening covers.
  • Use ladders and scaffolds safely.

o Extend the ladder at least 3 feet above point of support

o Inspect regularly and remove defective ladders from use.

o Never use ladders in horizontal position as scaffolds or work platforms.

o Never use metal ladders near electrical equipment.

o Do not adjust or move the scaffold while in use.

o Protect workers from overhead hazards.

o If a scaffold is higher than 10 feet, use guardrails, midrails and toeboards.

There are several ways you can avoid surface hazards related to floors, walls, holes, stairways, platforms and ladders or scaffolding. Here are a few to consider:

  • Keep floors clean and dry, free of debris, spills, spent materials, and stored materials; always use good housekeeping practices.
  • Provide warning signs for wet floor areas and mark permanent aisles and passageways and keep clear of obstructions.
  • Maintain drainage and provide false floors, platforms, mats, or other dry standing places where practicable, or provide appropriate waterproof footgear.
  • Keep all places clean, orderly, and in a sanitary condition.
  • Provide floor plugs for equipment, so power cords need not run across pathways.
  • Access to exits must remain clear of obstructions at all times.

For additional information visit www.osha.gov.

In the final post about safety we will discuss office safety.