When it comes to evaluating a roof restoration project, there are several key factors to consider before determining the best restoration system for the roof.
What is the building used for?
Understanding the building use is an important factor when determining the appropriate restoration specification. No one wants a roof leak, but it’s not hard to understand that if your roofing restoration system is over an operating room you need to make sure the restoration system you install is the best of the best and no corners are cut.
What is the roof makeup?
It’s important to determine the roofing membrane (such as TPO, MOD BIT, metal, etc.) and also what lies underneath it. Determining what the roof deck is, if there’s an insulation layer and how many layers of roof are currently installed, will help determine how water may flow or get trapped in the event of a roof leak.
Is there trapped moisture in the roofing system?
Roofing code allows for up to 5% moisture in the roofing membrane and 8% in the insulation layer. These are pretty low numbers. Liquid water, when it transforms into water vapor, expands 1600 times in volume which can cause blistering in the existing roofing system as well as in any new restoration.
If there is trapped water in the roof deck, what is it doing to the roof deck? Is it causing deterioration of the roof deck itself or structural components such as rebar and steel attachment? Moisture levels detected above the acceptable amounts will result in those areas of roofing needing to be replaced in addition to an inspection of the entire roof deck.
Does the roof pond water?
The National Roofing Contractors Association (NRCA) states ponding water for short durations is unavoidable and considered acceptable by NRCA and membrane roof system manufacturers, but ponding water in excess of 48 hours can be detrimental to the roof assembly. Roof systems should be designed and installed with positive drainage to prevent ponding from accruing—but as noted, some ponding can be unavoidable.
Understanding how much area ponds, and for how long after rain stops, is a huge factor in determining the appropriate restoration system.
What are the environmental factors?
Weather isn’t the only factor to consider. There are also unique aspects of the immediate environment that surround the building that should be considered. For instance:
- Overhanging trees
- Local air pollutants
- Chemical plants or manufacturing processes nearby
- All these factors can cause issues with cleaning the roof or keeping it clean during and after restoration. Additionally, if there are any type of chemical pollutant, the type of restoration products used can be drastically affected.
When determining the best possible roof restoration system, it’s not only about what adheres best to the roof membrane. So many factors must be considered, and proper evaluation and inspections must be conducted to make the best possible decisions.
If you need help or advice with a roof restoration project, contact us today.