CAPITAL-PROJECT CHANGE ORDERS, P.2

During the discovery phase, the engineer/architect must determine whether the underlying roof deck is flat or pitched — all too often, this goes undetected until after the roof has been torn up and the deck exposed. An improperly sloped roof causes water to pond, which deteriorates the roofing membrane and contributes to leakage. It will also likely void the roofing manufacturer's warranty. Simply put, a  properly pitched roof deck requires uniform insulation, which is the same thickness throughout, to maintain the proper slope. On a flat roof deck, however, tapered insulation must be installed to add pitch.
 
 A proper roof investigation includes probes to determine the thickness of the existing roofing system. These reveal whether a roof deck is flat and needs tapered insulation, which costs approximately $4 more per square foot than uniform. For a 10,000-square-foot roof, that amounts to an additional $38,000 change order.
 
 Magic Parapet Ride
 
 Installing tapered insulation may affect other items in the scope of work. With the newly added slope, the base flashing (the roof surfacing membrane that extends onto vertical walls) will reach higher up on the parapet wall than shown in the design documents. If the existing through-wall counterflashing (the metal flange installed into the parapets to prevent water from dripping behind the base flashing) is now too low, it will have to be replaced, increasing the cost of the project even more.
 
 Not identifying the roof deck as flat in the design phase could lead to still other change orders and costs. For example, if the height of the parapet above the finished roof surface is less than the 42 inches required by New York City Building Code, you will need to either install railings atop the parapets or add to the height of the parapet walls. In addition, bulkhead door saddles as well as skylights may have to be raised to accommodate the sloped roof.
 
 Top Two Requirements to Negotiate
 
 As a check against excessive change orders, your agreement with the contractor should state that the price of a base-bid item will be renegotiated when its quantity increases by more than 10 percent above what was specified in the original bid document.
 
 In addition, all change-order requests should be put in writing, reviewed by the engineer/architect and signed by the building owner or manager before the additional work is undertaken. Orally approving change orders will only lead to arguments later about who agreed to what.
 
 Despite additional work items that its building may face, your co-op or condo board should not automatically reject every change-order request, because some will be legitimate. The key is performing an appropriate level of investigation during the discovery phase of a project to avoid the big-ticket change orders that will haunt you later.

Stephen Varone and Peter Varsalona are principals at Rand Engineering & Architecture.

Adapted from Habitat July/August 2010. For more,  join our Archive >>