Wet VentingIncorporating Stack Venting and
NPC Harmonization
ONTARIO PLUMBING INSPECTORS ASSOCIATION INC.In the public service since 1920
OPIA Education and Training
Presented by:Rainier Bratsch-Blundel, CPSIPlumbing Professor – George Brown College
1
1 ¼”1 ¼”
1 ¼”
1 ½”
(e)
Wet Venting – Correct or Incorrect
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
1 ½”
3”
1 ¼”
1 ½”
2”
3”
1 ¼”
1 ½”
2”1 ½”
1 ¼”
1 ½”
(a)
3”
1 ¼”
1 ½”
1 ½”
2”
2” C/O
(b)
(c)
(d)
3”
1 ¼”
1 ½”
2”1 ½”
1 ½”
1 ½”
2”
• In the 2006 OBC, All Wet Venting requirements changed.
• Wet venting now includes– Stack Venting,– Modified Stack Venting, and the new– Multi-Storey Wet Venting
Rainier Blundel / Bryan Heyl George Brown College 3
7.5.2.1. Wet Venting
• Any fixture can be wet vented.• Any fixture other than a Water Closet (W.C.) can
do the wet venting• Symphonic fixtures can do the Wet Venting• Only fixtures with 2-inch trap arms and fixture
drains can connect into the wet vent above a W.C. (there is a 3-inch floor drain exception).
• The lowest connecting fixture is NOT included in the sizing of the wet vent.
Rainier Blundel / Bryan Heyl George Brown College 4
Wet Venting
• Wet Vent means a waste pipe that also serves as a Vent Pipe.
• Continuous Vent means a vent pipe that is an extension of a vertical section of a branch OR fixture drain.
• Fixture Unit means … the unit of measure … that expresses the hydraulic load … on the drainage system
Rainier Blundel / Bryan Heyl George Brown College 5
Wet Venting
7.5.2.1 Wet Venting(1) A soil or waste pipe may serve as a wet vent provided
that,(a) the hydraulic load is in accordance with Table 7.5.8.1.
7.5.8.1. Hydraulic Loads Draining to Wet Vents(1) The hydraulic load that drains to a wet vent shall conform to Table 7.5.8.1.(2) When determining the size of a wet vent, the hydraulic load from the most downstream fixture or symmetrically connected fixtures shall not be included.
6Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Venting
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.6” - 23 F.U.
Column 1 Column 2 Column 3
7
Maximum Permitted Hydraulic Loads Drained to a Wet Vent
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.3” 12 F.U. 8 F.U.4” 36 F.U. 14 F.U.5” - 18 F.U.6” - 23 F.U.
Column 1 Column 2 Column 3
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
• 3” wet vent (replaces old Stack Venting)– 1 or 2 water closets installed
• 8 fixture units maximum – 2” maximum above the lowest connecting fixture
8
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
9 (i)
a) the hydraulic load is in accordance with Table 7.5.8.1.
Continuous Vent7 metres
Bathtub
(1) A soil or waste pipe may serve as a wet vent provided:
2” shower
drain
Tank W.C.
Basin
Kitchen Sink
1 F.U.
1.5 F.U.
1.5 F.U.
3 F.U.
11 F.U.1 ½” pipe
Wet Vent (branch)7 F.U. (8 max.)3” pipe
Wet Vent (branch)7 F.U. (8 max.)3” pipe
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.2.1. Wet Vent Sizing
9 (ii)
7.5.8.3.(5) For the purposes of Table 7.5.8.3., the length of a
continuous vent shall be its developed length from the vertical soil or waste pipe connection to a vent stack, stack vent, header or open air.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.2.1. Wet Vent Sizing
9 (iii)Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.2.1. Wet Vent Sizing
7.5.2.1. Wet Venting
Rainier Blundel George Brown College 10 (i)
c) when 2 water closets are installed, they are connected at the same level to a verticalpart of the stack by means of a double fitting in accordance with Table 7.2.4.5.,
Continuous Vent
basin
Bath Tub
Wet vent
BranchFixture Units = 12Size = 3”
5 F.U. (8 max.)Size = 3” pipe
Fixture Units = 123 metres
Size = 1 ½” Pipe
b) the number of wet vented water closets does not exceed 2
Tank W.C.
Bath Tub
Tank W.C.
basin
Rainier Blundel George Brown College 10 (ii)
Rainier Blundel George Brown College 10 (iii)
11 (i)
d) the water closets are installed downstream of all other fixtures (on the wet vent)
Tank W.C.
Bath tub
Wet Vent (fixture drain)2.5 F.U. 2” Pipe
Continuous vent6 F.U. (BG)10 metres1 ½” Pipe
Basin
1 F.U.
1.5 F.U.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.2.1. Wet Venting
11 (ii)
d) the water closets are installed downstream of all other fixtures (on the wet vent)
Tank W.C.
Bath tub
Wet Vent (fixture drain)2.5 F.U. 2” Pipe
Continuous vent6 F.U. (BG)10 metres1 ½” Pipe
Basin
1 F.U.
1.5 F.U.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.2.1. Wet Venting
12
e) trap arms and fixture drains connected to the wet vent do not exceed 2 in. in size, except for connections from floor drains in accordance with Sentence 7.5.1.1.(3)(a) to (c),
Continuous Vent5 metres
3” Floor Drain
Tank W.C.
Basin
1 F.U.
3 F.U.
5 F.U.1 ½” pipe
Wet Vent (branch)1 F.U. (3 max.)3” pipe
Wet Vent (fixture drain)1 F.U. (3 max.)2” pipe
Note:
A-Table 7.4.9.3. Hydraulic Loads.Hydraulic Loads for Floor Drains.
No hydraulic load is required from a floor drain in a washroom since it is for emergency use only.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
No load
7.5.2.1. Wet Vent Sizing
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.6” - 23 F.U.
Column 1 Column 2 Column 3
13
Maximum Permitted Hydraulic Loads Drained to a Wet Vent
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
• 1 ½” wet vent– No water closet installed
• 2 fixture units maximum (2” maximum)– Above the lowest connecting fixture
14
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
15 (i)
A Laundry Tray (Tub) wet venting through a Floor Drain
F.D.
1 ½”Wet Vent
2 F.U. max.
1 ½”Continuous
Vent
1 ½”(1.5 F.U)
2”3”4”
Washing Machine
Stand Pipe (no load)
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
15 (ii)
A Laundry Tray (Tub) wet venting through a Floor Drain
F.D.
1 ½”Wet Vent
2 F.U. max.
1 ½”Continuous
Vent
1 ½”(1.5 F.U)
2”3”4”
Washing Machine
Stand Pipe (no load)
A-Table 7.4.9.3. Hydraulic Loads.
Hydraulic Loads for Laundry Traps.When determining the hydraulic load on a pipe, no allowance need be made for a load from a domestic clothes washer when discharged into a laundry tray, since the hydraulic load from the laundry tray is sufficient.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
• 2” wet vent– No water closet installed
• 4 fixture units maximum (2” maximum)– Above the lowest connecting fixture
16
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Size of Wet Vent(inches)
Maximum Hydraulic Load, Fixture Units
No Water ClosetsNot more than 2 W.C.’s
Fixtures Other Than a W.C.
1 ½” 2 F.U. -
2” 4 F.U. 3 F.U.
3” 12 F.U. 8 F.U.
4” 36 F.U. 14 F.U.
5” - 18 F.U.
6” - 23 F.U.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
Wet Vent Sizing (Table 7.5.8.1.)
17
A Lavatory Basin and a Bathtub wet venting through a Shower
2" WetVent
(4 F.U. max.)
1 14"
757R06B5
2"SANITARYTEE (TY)
SHOWER
1 12"Continuous
Vent
1 1/2"
Wet Vent Sizing (Table 7.5.8.1.)
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
18
f) the total hydraulic load on the wet vent does not exceed the limits stated in Table 7.5.8.1. when separately vented
branches or fixture drains in the same storey, having a total hydraulic load not greater than 2 fixture units, are connected to the wet vent or a wet vented water closet trap arm.
Continuous vent
Bath tub
kitchen sink
branchbathroom group7.5 fixture units
3” inch pipe
Tank W.C.
Lav
Wet Vent4 fixture units3” inch pipe
Continuous waste
and vent
Wet VentedBranch separately vented
fixture drain
fixture drain1.5 fixture units1 1/2” inch pipe
Note: the load from the separately vented kitchen sink is included when sizing this pipe
7.5.2.1. Wet Venting
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
19
Note: the load from the separately vented kitchen sink is included when sizing this pipe
Continuous vent
1 ½”shower
branch10.5 F.U.
3” inch pipe
Tank W.C.
Lav
Wet Vent6.5 F.U.
3” inch pipe
Continuous waste and
vent
Wet Vent
separately ventedfixture drain
fixture drain1.5 F.U.
1 ½” pipeKitchenSinkBath
tub
7.5.2.1. Wet Ventingf) the total hydraulic load on the wet vent
does not exceed the limits stated in Table 7.5.8.1. when separately vented branches or fixture drains in the same storey, having a total hydraulic load not greater than 2 fixture units, are connected to the wet vent or a wet vented water closet trap arm.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
20
Continuous Vent7.6 metres
Bathtub
kitchen sink
branchbathroom group7.5 fixture units
3” inch pipe
Tank W.C.
Lav
Wet Vent(fixture drain)
Continuous waste
and vent
Wet Vent(branch)
separately ventedfixture drain
fixture drain1.5 fixture units
1 1/2” inch pipe
(g) the hydraulic load to be considered when sizing a continuous vent, that serves a wet vent only includes the hydraulic load that is wet vented,
7.5.2.1. Wet Venting
3” inch pipe4 fixture units
1 1/2” inch pipe6 fixture units
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
21 (i)
kitchen sink
Wet Vent
Lav
Lav
Lav
kitchen sink
kitchen sink
TankW.C.
TankW.C.
symmetricalconnection
Fixture Units = 7.5Size = 3” pipe
Note: Any fixture above the symmetrically connected water closets must be included in sizing the wet vent.
Stack VentFixture Units = 15.5Length = 8 metresStack Base = 3” PipeSize = 1 ½” Pipe
(h) when a wet ventextends through more than one storey, the total discharge from any one storey abovethe first storey does not exceed 4 fixture units,
7.5.2.1. Wet Venting
(Waste Stack)
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
21 (ii)
kitchen sink
Wet Vent
Lav
Lav
Lav
kitchen sink
kitchen sink
TankW.C.
TankW.C.
symmetricalconnection
Fixture Units = 7.5Size = 3” pipe
Note: Any fixture above the symmetrically connected water closets must be included in sizing the wet vent.
Stack VentFixture Units = 15.5Length = 8 metresStack Base = 3” PipeSize = 1 ½” Pipe
(h) when a wet ventextends through more than one storey, the total discharge from any one storey abovethe first storey does not exceed 4 fixture units,
7.5.2.1. Wet Venting
(Waste Stack)
Table 7.5.8.4.Size and Developed Length of Stack Vents and Vent Stacks
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
22
Stack Vent
Lav
bathtubkitchen sink
Tank W.C.
drinkingfountain
nominally horizontal
offset
Wet Vent
Note:the definition of “Offset” means the piping that connects the ends of two pipes that are parallel
(i) there is not more than one nominally horizontal offset in the wet vent, and, ………………….
7.5.2.1. Wet Venting
(waste stack)
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
23
Stack Vent
kitchen sink
Lavnominally horizontal
offset(maximum length
1.2 metres for 2” inchor less pipe)
Wet Vent(waste stack)1 Fixture Units
1 ½” Pipebranch2.5 fixture units1 1/2” inch pipe
(i) there is not more than one nominally horizontal offset in the wet vent, and, ………………….
7.5.2.1. Wet Venting
(i.) the offset does not exceed 1 200 mm for pipes 2 in. or less in size, OR
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
24
Stack Vent
kitchen sink
Lav
Nominally Horizontal
Offset(maximum length
2.5 metres for pipelarger than 2” inch)
Wet Vent(waste stack)6 fixture units3” inch pipe
Branch9 fixture units3” inch pipe
Lav
kitchen sink
Lav
Lav
Lav
Lav
(i) there is not more than one nominally horizontal offset in the wet vent, and, ……………….
7.5.2.1. Wet Venting
(ii.) the offset does not exceed 2 500 mm for pipes larger than 2 in. in size,
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
25
Continuous vent
Tank W.C.
Lav
Bath tub
NotRestricted
(j) the wet vented portion is not reduced in sizeexcept for the portion that is upstream of floor drains in accordance with Sentence 7.5.1.1.(3),
7.5.2.1. Wet Venting
(k) the length of the wet ventis not limited.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
StackVent
Note:To size the Stack Ventuse Table 7.5.8.4.
7.5.8.4.(4) A stack vent serving a wet
vent stack that is over 4 storeyshigh shall extend the full size ofthe wet vent to open air.
StackVent
Same size
WetVent
as Wet Vent
over 4 storeys
high
But, ………..7.5.4.2.(2) A soil or waste stack that
serves as a wet vent does notrequire a vent stack.
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
7.5.8.4. Stack Vents or Vent Stacks (serving Wet Vents)
26
1 ¼”1 ¼”
1 ¼”
1 ½”
(e)
Wet Venting – Correct or Incorrect
Rainier Bratsch-Blundel / Bryan Heyl – George Brown College – Ontario Plumbing Inspectors Association
1 ½”
3”
1 ¼”
1 ½”
2”
3”
1 ¼”
1 ½”
2”1 ½”
1 ¼”
1 ½”
(a)
3”
1 ¼”
1 ½”
1 ½”
2”
2” C/O
(b)
(c)
(d)
3”
1 ¼”
1 ½”
2”1 ½”
1 ½”
1 ½”
2”
27
Wet Venting
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Code and Guide for Plumbing2006 Professional Edition
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OPIA Education and Training 28
Wet VentingIncorporating Stack Venting and
NPC Harmonization
ONTARIO PLUMBING INSPECTORS ASSOCIATION INC.In the public service since 1920
OPIA Education and Training
Presented by:Rainier Bratsch-Blundel, CPSIPlumbing Professor – George Brown College