April 28, 2009
We are designing, fabricating and installing the “nameplate” wall on a big box retail store. The project could not be any simpler. You would expect that if there was ever a Project that could be built with Approved Drawings rather than going to the extra expense of sending out a Field Measure crew, this would be THE PROJECT. If that is what you thought, you would be wrong.
You would not be wrong by a couple of inches, you would be wrong by THREE (3) Feet! That is correct; the General Contractor missed the framing layout by 1 Yard, 3 Feet, 36 Inches, 576 – One Sixteenths of an Inch (1/16” is the normal tolerance for our panels). In this day of Laser Levels, Theodolites, Total Stations, and Terrestrial Scanners, it begs the question, “does anyone still own a tape measure?” Or more precisely, “does anyone still own a tape measure, and know how to use it?”
Why are cladding contractors being required more and more to do costly field surveying while other Trades, like curtainwalls, are able to force general contractors to build by approval drawings? The answer is centered on the substrate to which we attach our cladding.
Compare a curtainwall system to a wall cladding system.
Curtainwall System
- Normally, the only substructure to which curtainwalls attach are the structural frame of the building.
- Curtainwall contractors control everything within their envelope of construction.
- Therefore, if the general contractor has any level of confidence in their structural frame, they feel confident on releasing the curtainwall contractor on the basis of their approved drawings.
Wall Cladding System
- This system may attach to a variety of substructures, including but not limited to: cold-formed metal framing, CMU, poured concrete, steel frame, etc.
- Each of these substructures may have a variety of diaphragm materials, including but not limited to: fiberglass reinforced gypsum board, plywood, gypsum board, etc.
- Then these diaphragm materials have a wide variety of membranes: peel and stick, breathable membranes, fluid applied, sheet applied, etc.
- The wall cladding contractor controls none of these elements normally.
- The general contractor usually controls none of these issues, so he does not want to release the wall cladding contractor based upon approval drawings.
Therefore, the wall cladding contractor is forced to field measure the project which requires money, time and effort. The wall cladding cannot start until the substrate is completed, field measuring takes place, and field measurements are incorporated into the approval drawings and part drawings. Only then can the wall cladding materials can be fabricated and shipped.
General Contractors make the assumption that the Wall Cladding should follow right behind the installation of the substrate. And it could if the substrate were produced in conformance with the Contract Documents and Approval Drawings. Currently, it is a rare occurrence when the substrate matches these documents. Therefore, Field Measurements are required and the perception is that the Wall Cladding Contractor is perpetually late.
What can be done to make this process more efficient? First, the stakeholders in the process must be educated. How many Owners, Architects and General Contractors actually understand the process? Hopefully, this Blog can be a first step in this education.
Please post your comments on how we can attempt to make the Process more efficient.
Thanks,
Ted S. Miller