1
Q
What is a roof system’s purpose?
A
(purpose of bldg. envelope)
-To provide a barrier between the interior and exterior environments so the interior can be controlled and maintained within reasonable limits.
2
Q
What do the components in a roof system control, and what are the components?
A
1) water penetration - controlled by the roofing
2) air flow - controlled by the air barrier
3) water vapour flow - controlled by the vapour retarder
4) heat flow - controlled by the insulation
3
Q
What is the key component in a roofing system, and why?
A
- The air barrier is the key component.
- Air movement is the largest source of heat loss/gain in the building envelope, and the air carries warm moisture from in the building to the exterior.
4
Q
What are the 3 types of roof systems?
A
1) sloped roof
2) conventional (compact) roof
3) protected membrane roof (PMR) (inverted)
5
Q
Describe a sloped roof. Include:
- slope
- spacing info
- roofing info
A
- gentle to steep slope, pitched to drain out to eaves
- may have a large ventilated space between the roofing and the insulation/air/vapour retarder
- roofing is not water tight, must be sloped to shed water
6
Q
Describe a conventional (compact) roof. Include:
- slope
- components
A
- sloped min. 2% (1:50) to drain
- roofing
- insulation
- air/vapour barrier
- supporting structure
- sometimes ballast is required for:
- u/v protection
- weight
- holds materials in place (when loose-laid)
- affects water flow
- protection from foot traffic
7
Q
Describe a protected membrane roof (PMR) (inverted). Include:
- slope
- comparison
- new components
A
- slope min 2% (1:50)
- similar to conventional except roofing is installed below insulation
- water permeable fabric over insulation to help protect insulation from u/v (if needed) and distribute weight of the ballast over joints in insulation to prevent dislodging
8
Q
What are the 3 types of roofing?
A
1) built up roofing (BUR)
2) single ply roofing
3) modified bitumen
9
Q
Describe built up roofing. Include:
- components and their purpose
- installation facts
A
- bitumen is waterproofing and adhesion
- 4 plies of felts give strength and stability
- surfacing (pea gravel) protects from u/v, foot traffic, and erosion due to wind/rain
- the surfacing is glued down to felts with a flood coat of bitumen
- usually requires a fibreboard overlay above the primary insulation (to protect insulation from hot bitumen)
- it’s proven, economical, fast and easy to install
10
Q
Describe single ply roofing. Include:
- roll sizes
- membrane thicknesses
- laid type
- membrane type
A
- in rolls up to 10’ to 45’, 200’ long
- thicknesses range from 45 mil to 90 mil
- may be loose laid + ballasted (45mil), or fully adhered, or mechanically fastened (60-90mil)
- always fully adhered or mechanically fastened at roof perimeter
- thermoplastic (PVC, EP, TPO) - softens when heated, return when cooled - laps/seams are hot air welded - don’t need to be covered - very strong against tear or puncture
- thermoset (elastomeric) -EPDM - solidified when heated (irreversible) - is cured (vulcanized) -can only be bonded with adhesive - seams are lapped and glued
11
Q
Describe modified bitumen roofing. Include:
- thermoplastic vs. thermoset
- components and application
- installation facts
A
- chemically modified to be thermoplastic + elastomeric
- base sheet and cap sheet (2 plys)
- rolls are 1m wide, 8-15m long
- base and cap sheets may be torched or mopped in place
- cap sheet is laid parallel to base sheet but offset 300 to 400mm from base sheet
- cap sheet may have a coloured pebble surface
- relatively lightweight (good for reroofing)
- proven
- most slopes and shapes
- usually requires fiberboard overlay to protect insulation
12
Q
What are the 3 ways to install single ply roof systems?
A
1) loose laid and ballasted
2) mechanically fastened
3) fully adhered
13
Q
Explain a loose laid and ballasted single ply roof system. Include:
- slope
- height
- components
- installation facts
- membrane type
- membrane thickness
A
- max slope 2:12
- max height 75’ (23m)
- ballast is used to hold down all components
- ballast is smooth, river washed 35mm diameter (min.) 10lbs/sf (min.)
- relatively inexpensive, fast and easy to install (wide rolls - 50’)
- odourless, durable, proven
- membrane type: *EPDM, TPO, EP, PVC
- membrane thickness 45mil (1.1mm)
14
Q
Explain a mechanically fastened single ply roof system. Include:
- slope
- height
- components
- installation facts
- membrane type
- membrane thickness
A
- max slope 4:12
- max height 120’ (36m)
- use min. 60 mil (1.5mm) membrane, rolls 2.4m to 3.0m (8’-10’) wide
- poly iso is most common
- lightweight
- any shape
- aesthetically pleasing/advertising/logos
- light colour may mean more energy efficient (solar gain)
- easy to fix
- membrane types: EPDM, **TPO, *EP, *PVC
15
Q
Explain a fully adhered single ply roof system. Include:
- slope
- height
- roll size
- installation facts
- membrane type
- membrane thickness
A
- max slope - unlimited
- max height -250’/76m
- use 60mil (1.5mm) membrane thickness
- roll width usually 3~6m wide (10’-20’)
- great on concrete deck
- best for uplift
- any slope/shape
- all benefits of mechanically fastened
- membrane type: EPDM, *TPO, *EP, *PVC
16
Q
How can most membranes be installed? (notes for all roofs)
A
Conventionally, or inverted.
17
Q
Regardless of roofing type membrane is attached how? (notes for all roofs)
A
It is mechanically fastened or fully adhered @ perimeter (uplift).
18
Q
Can a roof be flat? (notes for all roofs)
A
No. Must have min. 2% slope to drain.
19
Q
Reminder. (notes for all roofs)
A
Always include an a/v barrier + consider support for it (when on steel deck).
20
Q
Why must we consider insulation types based on roofing?
A
Some insulation types may require a cover board (overlay).
21
Q
What accounts for most roof related problems?
A
Failures at roof penetrations.
22
Q
What are some examples of roof related problems?
A
- absorption of water (insulation/coverboard)
- deformation by/due to freezing
- fungus attack, decay of wood or steel deck
23
Q
Tie-in Reminder
A
The tie-in of the roof system is critical.
24
Q
What is the most important component of the roof system to tie-in?
A
The air barrier *NRC test on high+low bldgs show 30-50% of heat loss can be contributed to air leakage.
25
Name types of roof penetrations.
- parapets
- roof drains
- plumbing stacks
- access hatch
- curbs for mech.
- skylights
- cleaning equipment curbs, ties
- roof/wall intersections
- garbage chute
- firewalls
26
How far does roofing extend at parapets/curbs vs. at walls?
300mm for parapets/curbs
| 450mm for walls
27
Notes for detailing parapets
- roofing is fully adhered at parapet
- roofing may or may not require a cant strip (depends on roofing flexibility)
- extend a/v barrier up and over and cover with insulation to prevent condensation
- metal cap flashing to cover top of parapet, sloping 1:10 min. back onto roof (prevents staining of wall)
- always slope roofing/insulation away from walls
- all masonry above the roof must be filled solid
- all wood above roof must be pressure treated
28
What are the 3 major influences on site development?
- zoning
- municipal services/engineering
- traffic/access
29
Municipal services/engineering
- ensure site servicing components are functioning, attractive + appropriately screened from public view
- availability, size + location of water, sanitary, storm, gas, etc.
- if no san. sewer, must include for septic system ($, space)
- location of utility poles - whether they have transformers or not
- easements (legal survey)
- loading areas - including garbage facilities (appropriately screened) and with proper access + turn around facilities
- place utilities underground where possible
- soil characteristics (bearing, storm water management, watertable)
30
Traffic and access (from site to roadway)
How does this impact design
31
What are the city/regions design goals? (Traffic and access)
1. Protect public through orderly control of traffic movement onto and from roadway
2. Maintain traffic carrying capacity of roadway
3. ensure uniformity of construction + design
32
What is regulated? (Traffic and access)
1. # of access routes allowed
2. location of access
3. width of access
4. radius of access
5. angular placement
33
How is access regulated?
- By type of access
1. non-commercial (residential use, house, farm/field use, up to 6 units)
2. commercial (residential 6+ units other than field or farm)
3. high volume (shopping centre, arena)
- speed of the roadway
- low speed <70km/h
- high speed ≥ 70 km/h
- proximity to intersections, rail lines, + other accesses
34
What does zoning begin with?
The "official plan" which is a document prepared under auspice (direction/guidance) of the ontario planning act, which sets out the guidelines for the development of the community
35
What does planning do?
Planning divides the city into zones which restrict the development of lands + term of what can be developed and how it can be developed
36
What does our zoning map show?
Our zoning map shows the zones + zone densities such as industrial, residential, commercial, green, agricultural, etc. The # beside the zone are density (ex. R1, R2, R3, I1, I2)
37
Where does the structure of the zoning bylaw start?
Bylaw begins with general items like definitions, parking, loading, obstructions, special cases + other general provisions.
38
What is the 2nd section of the zoning bylaw?
Zone specific regulations.
- permitted uses
- ancillary uses, complimentary uses
- prohibited uses
- prohibited near residential
- performance standards
- min. lot frontage
- yard requirements (setbacks)
- bldg height
- lot area (min)
- landscape area (min %)
- off street parking
- min. # of spaces required (based on area, # of suites, # of beds, # of employees)
- off street loading
- shipping/receiving/garbage
- residential - may dictate # of each bed type
39
Where do you submit a site plan review and approval and who views it?
- submit to the planning department
| - viewed by bldg department and engineering
40
What does the site plan review and approval process do?
Gives each municipality the power to deem any part of a city/region as a site plan control area. This control was given over by the province.
41
What is the site plan review and approval for?
- It gives the municipality the authority to review + influence design, in addition to meeting requirements of the zoning by-law and the OBC.
- It's a form of development control.
- Another level of approval required before a building permit is issued.
42
What is the purpose of the site plan review?
To allow the city/region and other jurisdictional agencies the opportunity to review:
- overall site design
- impact of the proposal on surrounding land use
- siting of structures + bldgs (massing and conceptual design)
- the widening of public roads which abut the site
- easements, access, parking, + loading
* -grading and site drainage
- provision for water management
* -landscaping and buffering, amenity areas
- curbs, signs, walkways, lighting, fencing, storage of waste
- exterior design, sustainable design, + universal design
43
When is a site plan review required?
* -new bldgs, bldg additions, substantial change
- also required for commercial parking lots
* not required for single family homes, semis, or farm bldgs
44
How does the submission process work?
- often begins with a pre-consultation meeting to determine requirements
- preferable to submit near complete contract documents
- the key is a coordinated application
45
What does/may a submission include?
-site plan
-grading plan
-site servicing plan
-landscape plan
Sometime need to submit (upon request):
-elevations
-perspectives
-building sections
-lighting plans
46
How does the process work?
- We submit multiple copies (approx 11 min.) of dwgs along with site plan, application form, and applicable fees
- site plan review coordinator circulates application to all applicable agencies asking for comments
- comments are received, then committee meets to review and discuss
- this committee is a "technical advisory committee appointed by council to review a provide recommendations on site plan applications"
- applicant may be invited to a review meeting to support the proposal
47
What is the committee made up of?
- planning
- building
- engineering
- landscaping
- community member
48
How long does the process take?
5 weeks and no bldg permit can be issued without approval
49
What do the applicant results look like?
They will be one of the following:
- approved
- approved subjected to certain conditions (deferred)
- refused
50
What is the next step after the applicant results are received?
- owner enters into a site plan agreement to ensure the enforcement
- various fees + a deposit for the site work (50% of the site costs, min. $1000 to max. $50,000)
51
Where to use dampproofing?
"Where the exterior finished grade is at a higher level then the inside ground level, walls shall be dampproofed unless they are waterproofed"
52
Where to use waterproofing?
1) where hydrostatic pressure is present, walls + floors of interior surfaces lower than grade must be waterproofed
2) roofs of underground structures need to be waterproofed
3) elevator pits usually waterproofed
53
Dampproofing Notes
- if CMU, parge walls with 10mm parging
- fill holes from ties if concrete walls
- apply asphalt emulsion (spray or rolled)
54
Waterproofing Notes
- if CMU, parge walls with 10mm parging
- fill holes from ties if concrete walls
- hot fluid applied rubberized asphalt, sheet rubberized asphalt
- sprayed or trowelled
- floors to be waterproofed require a 75mm mud slab (concrete)-waterproofing between 2 layers of concrete
55
Foundation wall drainage system
1) drainage tile
| 2) drainage layer (an integral part of our drainage system)
56
Drainage tile note.
Required to have a 100mm (4") weeping tile along bottom with top and sides covered with 150mm min.
57
Drainage layer note.
1) 19mm Mineral wool insulation
2) 100mm (min) Free draining granular material
3) Pre-fab drainage system.
58
What are some types of pre-fab drainage systems?
* -Dimple board (delta ms, system platon)
* -Perimate insulation (dow)
- Grooved
* -Owens Corning (pink) XPS grooves/dimples
- 3 dimensional core with a geotextile bonded to face, keeping soil particles from blocking drainage area.
- WR meadows (mel drains)
- Grace (Hydro Duct)
- MIRAFI (miradrain)
*- Vertical applications only
59
Where do you typically find plaza decks?
- above parking garages
- roof terraces and gardens
- balcony above habitable space
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