Productively Playing the Weather

Written by Tim Simpson, Quality Assurance and Quality Control Manager, Maintenance Coatings Inspector


Work the weather to your advantage and not the other way around. Here are a few pointers:

  • Wind usually picks up in the afternoon, so plan your spray work accordingly.
  • Setup spray targets on poles in parking lots with a black background on the targets to confirm overspray issues and to reassure the customer there are precautions in place.
  • Install a temporary series of wind flags that the spray person can readily see on the rooftop to monitor current and changing wind direction from the rooftop to adjacent buildings and parking lots.
  • Be smart and make the call to discontinue or not spray if the wind conditions are not right for a specific location. Overspray insurance, while safe, is costly. 
  • Don’t despair about your schedule. You can still get that coat on your roof if you have prepared for contingencies. Here is how: 
    • Give the crew 18” long nap rollers on extension poles and take the tip and tip housing off the airless sprayer. 
    • Deliver ribbons of material in lines following a pattern back and forth across the roof so that the crew can quickly roll out the material being delivered on the roof. 
    • Be careful when pulling the trigger as the gun and wand will tend to surge upward when the trigger is pulled. 
    • Hold the gun with one hand and the wand with the other hand to keep the wand from surging up and accidentally spraying a half-gallon of material across the roof at random. 
    • Remember that the pump can deliver 1-3 gallons of material a minute onto the roof surface despite using a spray tip or bulk pumping the material out of a tipless assembly ahead of a roller crew. 
    • No need to bring buckets up on the roof for pouring and rolling when using this method. You may be surprised how quickly you knock out a coat across the entire roof. 
    • Use this method also for rapid material delivery on a roof that is not suited for spraying due to proximity to adjacent parking lots and other obstacles. 
    • Consider this as a Plan B to maintain high production and keep the projects moving. Don’t forget you can modulate the pump’s volume by turning the pump regulator up or down as needed.
  • In colder temperatures know drying times and closely monitor the weather. Avoid applying roof coatings when the temperature is 50 degrees and dropping and when rain is forecasted within 24 hours. Night fog and morning dew can also cause issues with wet coatings allowed to dwell during the night because of saturated air reaching the dew point, high humidity levels slowing dry times, etc. Have a plan to postpone if the weather does not cooperate and let the weather improve.
  • Masking Roof Drains – This is an important item to remember. Some contractors will mask internal roof drains to keep them clean while spraying. If there is any suspicion of inclement weather in the forecast, it is important to remove masking from the roof drains right after you spray around the perimeter of the drains. If the next day brings rain and the roof drains are sealed off with masking materials, the roof could flood with excessive amounts of water re-wetting the recently applied material, causing roof structure overloads and possible collapse. All avoidable when demasking critical roof drains as along the way. It’s much easier to re-mask the roof drains a few times than explaining results of the other scenario to the client or insurance carrier.


Click here for Chapter 12: Setting Up Ground Game When Doing Roof Work