We were recently engaged to inspect a two year old roof that was having some issues. Of the numerous roofing sins that were committed during install, the edge metal is likely the most egregious. For those not familiar with edge metal assemblies, the grey aluminum metal pictured below is a called a hook-strip and is principally responsible for holding the roof on along the perimeter of the roof where significant uplift pressures are borne during high wind events. The holes in the picture below are factory-punched holes utilized for securement to the wood blocking on the top of the exterior wall. Judging from this picture and the second picture, the contractor struggled to properly correlate the wood blocking height with the installation of tapered insulation. In the second picture the roof is higher than the perimeter flashing. The contractor may have field-drilled holes to accommodate proper securement but the only way one would ever know that is by removing the cover which would be a costly venture due to safety concerns, or if the whole assembly blew off or at the time of re-roofing. Given the proximity to the ocean and the associated high wind speeds, this defect could lead to a catastrophic failure. The last image shows a walk pad set in bonding adhesive. As is obvious, this is improper securement and will lead to the walk pad flying off the building at some point and perhaps injuring someone or damaging property.
Roof installation defects are often very difficult to resolve for the following reasons. 1.) The owner often doesn't have adequate understanding of what they're buying and therefore does not know how to measure the quality of the work. In a perfect world this shouldn't matter because the project team would fill the gap in the owner's knowledge by providing what he needs and is paying for. 2.) Often the contractors are very difficult to get back to a job site and will point to all sorts of other reasons as to why the roof is not performing while all the while the owner is stuck with unhappy occupants and mounting bills due to damage, not to mention the psychological burden of what's going to happen. This behavior is not necessarily malicious, the contractor may legitimately not know what the problem is or how things ought to be done. 3.) The confusion created for the owner buy the preponderance of 'opinions' and recommendations he finds when he starts to do his own research.
What's to be done? Firstly engaging a qualified Registered Roof Consultant on the front end of the project will ensure that the scope is properly defined and the the owner's expectations are properly set. Secondly, engage a qualified Quality Assurance observer to perform at a minimum periodic site inspections during the work. Errors caught and remedied during the installation present little to no interruption to the owner's world or building occupants whereas remedies applied after the fact are often extremely costly and burdensome.
Roof in this image is 'above' the perimeter flashing.
A walk-pad that will one day be a flying projectile if not remedied due to improper installation.