1. Foundations of Real Estate Management
BOMA International
Module 4: Building Operations II
Roofing Systems

2. Objectives List the components of a roofing system
Describe the difference between built-up roofs, modified bitumen roofs, and single-ply roofs

3. Roofing Systems
Out of sight…
out of mind

4. Roofing Systems Long-term fixed asset
Use life cycle cost analysis to determine best roof system for your application
Goal: Longest roof system life with lowest life cycle cost

5. Why Do Roofing Systems Fail?
End of the roof’s useful life
Inadequate maintenance
Poor or improper design
Poor or substandard installation
Faulty materials

6. Roofing Components Decking (deck) Insulation Roofing materials
Concrete or corrugated steel panels
Insulation
Roofing materials

7. Roofing Systems Flat roofs Pitched roofs Drains and gutters
Not really “flat” – there is some degree of pitch
Usually pitches to front or back of property
Sometimes pitches to the center
Pitched roofs
Drains and gutters

8. Roofing Systems Inspect roofs for ponding Keep the insulation dry
Increases chance of leaks
Adds significant amount of weight
Keep the insulation dry

9. Common Roofing Systems
Built-up roofs
Most expensive installation cost
Modified bitumen roofs
Moderately expensive installation cost
Single-ply membrane roofs
Least expensive installation cost
All roof systems should have walk paths to prevent damage

10. Built-Up Roofs Alternating layers Usually 3-4 layers
Roofing ply sheets (felt)
Asphalt or coal tar pitch
Usually 3-4 layers
Final layer is either topped with gravel or is smooth (top sheet)

11. Built-Up Roofs

12. Modified Bitumen Roofs
Residual material after crude oil is refined (“the bottom of the barrel”)
Instead of ply sheets, system uses thermoplastic or elastomeric coating materials and bitumen
Usually 2 layers – base sheet/top sheet
Fire hazard – fire watch for 60 minutes after work has concluded

13. Modified Bitumen Roofs
Applied with hot asphalt, a propane torch, or cold asphaltic adhesive

14. Modified Bitumen Roofs

15. Single-Ply Membrane Roofs
Made up of a single ply of roofing material
Three main types:
EPDM (ethylene propylene diene monomer)
Rubber
PVC (polyvinyl chloride)
Vinyl
TPO (thermoplastic olefin)
Plastic

16. Single-Ply Membrane Roofs
Adhered to the roof:
Ballasted (stones)
Mechanically attached (fasteners)
Fully adhered (adhesives)

17. Single-Ply Membrane Roofs

18. Single-Ply Membrane
Ballasted roof system

19. Mechanically attached roof system
Single-Ply Membrane
Mechanically attached roof system

20. Fully attached roof system
Single-Ply Membrane
Fully attached roof system

21. Single-Ply Membrane Seams Can be manufactured in white EPDM
Seams are sealed and need routine maintenance
PVC and TPO
Seams are heat welded together
Can be manufactured in white
Does not reduce cooling costs
Upper floor HVAC system is insulated
Does reduce heat island effect in urban environments

22. EPDM Seam Management

23. Roof Maintenance Best Practices
Semiannual roof inspections
Equipment installations on roof and roof penetrations should always be supervised by roofer holding warranty
Remove leaves, plant material, and trash on regular basis
Inspect drains and ensure drains work properly

24. Grass growing on the roof
Roof Maintenance
Grass growing on the roof
This is not a green roof!

25. Roof drain clogged with debris
Roof Maintenance
Roof drain clogged with debris

26. Roof Maintenance
Remove debris. Better yet – don’t let it accumulate in the first place!

27. Roof Warranty Usually 10 to 25 years Understand warranty requirements
Roof inspections and preventive maintenance are usually required
Keep copies of all documentation!
Make sure you use vendors certified and approved by manufacturer

28. Green Roofs Partially or totally covered with vegetation Advantages
Amenities space
Reduce heating and cooling costs
Reduce “heat island effect”
Increase lifespan of the roof
Reduce storm water runoff
Filter pollutants and CO

29. Green Roofs