IBC (International Building Code is the Code of Jurisdiction in the South East) defines Roof Coverings:
1. Shall provide weather protection for the building.
2. Shall be applied to a solid substrate or structural deck.
Two Generic Definitions
Steep Roofing – Roof coverings applied on decks with slopes greater than 3” inches.(Ie: Shingles, Metal Roofs)
Low Sloped Roofing – Roof Coverings applied on decks with less than 3” inches. (Flat Roofs)
Since 1997 SBCCI/IBC Code requires ¼” per foot slope for all buildings. (There are no “FLAT” roofs)
Steep Roof Coverings
Shingles – On slopes that are 3 / 12 or greater.
Slate – On slopes that are 4 / 12 or greater
Wood Shakes – Many Fire Code restrictions.
Standing Seam Metal- Minimal Restrictions.
Concrete & Clay Tiles- On Slopes 4 / 12 or greater.
Sloped Roofs – Shingles
Standard Three tab
25 year MFG Warranty
Most are “Lifetime Warranty”
They are heavier and thicker with more asphalt and granules
Shingles – Architectural
Low Sloped Roof Components
Structural Deck- Metal, Concrete, Wood, Gypsum, Light Weight Concrete (LWC), Cementitious (Tectum)
Insulation– Wood Fiber, Fiberglass, Perlite, Urethane, Styrofoam, Polyisocyanurate (Most used in last 25 years)
Roof Covering – Built up (BUR), Single Ply, Metal
Surfacing Material – Gravel, Coatings, Emulsions, Asphalt
Flashing – Metal or Same material as roof covering.
Roof Coverings – Built Up Roofs (BUR)
(Pronounced = BITCH – U – Men)
Coal Tar Pitch
The Bitumen in the BUR is the water proofing material, weather it is Asphalt or Coal Tar Pitch. It is also used as the adhesive for various insulation attachments and the adhesive for the inter-ply of felt (tar paper) to form a monolithic membrane.
Most BUR Felts are saturated with either the coal tar or asphalt depending on the system. Coal Tar Pitch is approximately 15% higher in cost but last longer as it never solidifies.
Asphalt Built Up roofs are the most popular BUR application in today’s construction.
Low Sloped – Gravel Surfaced Asphalt Built Up Roof (BUR)
Roof Coverings– Single Ply Membranes
Modified Bitumen Membranes
Thermosets – EPDM (Rubber)
(Ethylene Propylene Diene Monomer)
(PVC, TPO, CPE)
Roof Coverings – Modified Bitumen
Modified Bitumen membranes look like the old “Roll Roofing” material. They are usually granular surfaced with Polyester or Fiberglass reinforcing fabric.
The back of the membrane contains the Bitumen adhesive. The adhesive is either:
SBS (Styrene Butadiene Styrene) Mop grade activated by melting the back of the sheet with hot asphalt applied with mops.
APP (Attactic Polypropylene) Torch Grade activated by heating the back of the membrane with a flamed torch.
The Modified systems are usually fully adhered and are used in BUR configurations. We typically see 2-3 plies of built up roofing felts with a CAP SHEET of Modified Bitumen. We refer to this application as a “HYBRID” roof system, combining a Built up roof and a Modified Roof.
Roof Coverings – EPDM (Rubber)
Ballasted – The rubber membrane is loose laid and held in place with ballast such as large rock or concrete pavers.
Mechanically Attached – The mechanically attached systems hold the membrane in place with screws and fasteners on a specific interval.
Fully Adhered – Fully adhered systems are held in place with glue or adhesive to the insulation substrate.
Low Sloped Roofs – Mechanically Attached Rubber (EPDM)
Roof Coverings – Thermoplastics
Thermoplastic Membranes have several members of its family.
PVC, TPO, CPE, Hypalon
Thermoplastic Systems can be Ballasted, Mechanically attached, or fully adhered.
Seams are all heat welded in lieu of adhered with glue or tape as in the Rubber systems.
Thermoplastic Membranes are typically white and are all reinforced with fabric.
Low Sloped PVC – Sarnafil Roof
Low Sloped Roofing Systems
Sarnafil – PVC
SoCo Roofing Primarily Installs “Sika-Sarnafil” PVC roof membrane systems.
“Energy Star” approved, white membrane provide energy savings to the owner which Increases your NOI.
The system installation is less disruptive to the center operations.
The “Deeper Pockets” of the Manufacturer provides assurances to the owner. (Warranty $$ are held in escrow until claim is made)
Design Options with the system gives the Owner Cost saving options to increase NOI.
Why SoCo Prefers PVC by Sika Sarnafil
Good in Most Situations on
Low Sloped Roofs
a. Tear offs or recovery Applications
b. Regardless of Existing System
d. Low Maintenance = Lower Cost (Increase NOI)
e. Best over All Life Cycle Costing (20% savings or more)
Typical Roofs on Commercial Buildings
1. Steep Roofs
b. Standing Seam Metal
2. Low Sloped (Flat Roofs)
c. PVC / Thermoplastic
d. Modified Bitumen
Low Sloped Roof System Types
Single Ply – Modified Bitumen
Single Ply – EPDM (Rubber)
Single Ply – Thermoplastic (TPO, PVC)
Asphalt Built-Up (Tar and Gravel)
Asphalt – Hybrid (2-3 layers with Modified Bitumen Cap)
All Roof systems require routine maintenance to protect the owners investment.
A routine preventive maintenance program will enhance the overall service life of the system.
Preventive maintenance will postpone costly re-roofing.
Inspections made twice a year will enable you to head off costly problems.
Budgeting and Forecasting
Your Preventive Maintenance program will provide you information for forecasting roofing needs.
Always allow for “Emergency Roof Repairs”
Include inspection costs in your annual budgets.
Do a five year forecast for your facilities.
Implement a Data Base program when feasible.
Re-roofing vs. Repairs
1. Age of Existing System
2. Condition / Leak History
4. Cost of Repairs (Exceeds 1/3 of re-roofing cost?)
5. Estimated Service Life After Repairs
6. Future of the Building Ownership
Building Code (IBC)
International Building Code
Recovering – The practice of preparing the existing roof system and surface and then installing the new roof system directly on top of it.
Replacement – The practice of removing the old roof assembly to the structural deck, repairing any damaged decking, and installing the new roof system.
Re-Roofing – The process of recovering or replacing an existing roof system.
Recovering Vs. Replacement
Section 1510.3 (2000 international Building Code)
“New roof coverings shall not be installed without first removing existing roof coverings where any of the following conditions occur”:
1. Where the existing roof or roof covering is water soaked.
2. Where the existing roof covering is wood shake, slate, clay, cement, or asbestos – cement tile.
3. Where the existing roof has two or more applications of any type of roof covering.
For the past 25 Years the rigid insulation used in roof systems is “Polyisocyanurate” or “Urethane Foam”.
They are Water resistant with a very high “Thermal Value”.
Newer Energy Codes require a minimum of R-20 in Commercial Buildings. (some jurisdiction’s require R-24-30)
In many cases we can “Re-use” existing insulation saving on project costs.
Roof Consultants Institute (RCI)
Standard Building Code (SBCCI)
International Building Code (2000)
Construction Specification Institute (CSI)
Roofing Industry Educational Institute (RIEI)
National Roofing Contractors Assoc. (NRCA)
SoCo Roofing Services (socoroofingservices.com)
References Contact Info.
RCI – 800.828.1902 / www. rci-online.org
NRCA – 847.299.9070 / www.nrca.net
RIEI – 303.703.9870 / www.riei.org
CSI – 800.689.2900 / www.csinet.org
ICC – 703.931.4533 / www.iccsafe.org
SoCo Roofing Services / www.socoroofingservices.com