Visual Roof Inspection vs Roof Leak Investigation

June 2, 2021 Laura MacCormac




A roof leak investigation is much more detailed than a visual roof inspection.  It is important to understand the difference because often a free roof inspection doesn’t examine below the first layer of the roof and doesn’t look for hidden problems.  The result is two very different quotes: one showing obvious and known work and the other includes roof issues that were unknown and hidden.


Free Roof Estimates

Free estimates, roof assessments or visual inspections: these are all one and the same. This is usually a free-of-charge offer and a roof repair quote is included.  Note that any issues found during the roof repair process will have to be quoted separately if they weren’t found during the original inspection.  It is helpful to give the contractor as much information as you have about the roof and what you believe needs to be done.  Maybe you know about existing roof damage or that an area of the roof needs to be replaced.  The contractor will make sure this shows up on the estimate.

What you get: A quote containing work that needs to be done to maintain the roof plus anything you have specifically requested.


Roof Leak Investigation

When there is an obvious roof leak your roofing technician will need to trace that leak to its origin. This investigation is thorough and will uncover the extent of the damage that has occurred.  Often times more than one issue is found because the tech needs to find weaknesses and then confirm that it is the cause of the particular leak. As they investigate a weakness and test it, they could find other leaks and defects that haven’t shown up inside the building but are causing damage to the roof structure.  As a result the quote will be much more comprehensive than a free quote would be.

What you get: A quote containing work that needs to be done to repair parts of the roof that are failing.



Which Type Should You Use?

The service you choose depends on the situation.  The no-charge roof assessment is part of an on-going roof maintenance program.  Usually the review is done yearly and the purpose is to give you an idea of how much work needs to be done to keep the roof in good shape.  The technician uses a checklist and looks for specific wear and tear like rusting and failed sealant.  If you have been keeping the roof maintained and have the information about work that has been done previously and there haven’t been any damage or leaks, this is an appropriate option.


When there has been damage or if ingress is occurring a formal investigation needs to be done to determine all the steps that will be required to fix it.  It’s also important to have as much documentation as possible when there is a roof leak for insurance purposes and for the on-going health of the building.  A leak investigation report comes with photos of each step of the investigation and the subsequent repairs.


Inverted Roofs

Inverted roofs are a special case because the roof membrane is underneath the insulation.  Since the membrane is a waterproofing layer, defects won’t be found without an investigation.  You cannot tell by visual inspection if there is a problem with that membrane.  Inverted roofs are popular in the GTA and are also referred to as protected roofs. If you are managing a building with an inverted roof beware of contractors who tell you that a free visual inspection is going to produce a realistic quote.


Leak Investigation Process

Here is a typical process for a leak investigation.  You will notice that a visual inspection would not turn up the defects that are found here.

  1. Interior Inspection – Assess the reported leak area. Measure interior space to trace to roof surface.
  2. Cut drywall or lift tile to determine if further indication of water ingress is present behind ceiling (if possible).
  3. Inspect space between leak area and roof (if present) – Attic, crawlspace, mechanical room, etc.
  4. Trace out investigation area on roof surface based on interior measurements.
  5. Inspect membrane and surrounding items above leak area for defects (membrane to be exposed on inverted roof).
  6. Perform cut tests. Determine make-up of roof system and if there is presence of moisture under membrane.
  7. Apply compatible temporary or small repairs.
  8. Reassemble the roof system (gravel ballast, paving stones, deck boards, etc).
  9. Provide project summary report with further recommendations.


« Prev Next »