Design Consideration:
To slope or not to slope roof structure
| Flat - Level Structure |
Sloped Roof Structure |
| BENEFITS |
PROBLEMS |
| Constant size of Plenuem |
Variable height results in narrow height restriction |
| Eases Mechanical + Plumbing installation |
Installation of Mechanical may be compromised |
All structural elements are standard
Less material cost, faster construction |
Structure elements varies increases cost of material + labor |
|
EICRS sloped system provides
Average R |
EICRS constant thickness
Constant R |
The extra cost of installing an Average R value with EICRS on a flat roof structure vs. a sloped roof is less than 10%. A bit more material, some more labor. Considerably less than the direct cost of sloping the steel, and even less than the additional cost in the design and installation of the mechanical elements.
On a sloped metal roof deck - not requiring 1 hr. fire rated construction, the isocyanurate system may have an initial cost advantage. However - the initial saving is rapidly lost because of the inferior performance of the isocyanurate system - i.e., intolerance to traffic, lack of a heat sink, shrinkage, and especially in the major cost in re-roofing - e.g., REMOVAL, DISPOSAL, REPLACEMENT. In addition, considerably savings can be obtained by incorporating the stiffening action in the EICRS on the metal deck - allowing for savings in the gauge of the metal deck and/or welding pattern. See Mr. Structural Engineer - table: ICBO 3081
Design Service Provided by Cell-Crete Corporation Let us assist you in designing the slope pattern of your roof. Send us plans in e-mail format to pbarclay@cell-crete.com in any the following formats: AutoCAD Drawing (*.dwg), TIFF Bitmap (*.tif), or Dodge (*.pln).
- We will provide Roof plan slope to drain layout
Show the elevations at various locations - i.e., perimeters, penthouse doors, stairway, equipment platforms, etc.
Provide an average R-value - e.g., R-19, R-24, R-30
- Provide a budget estimate.
Next... |
