(SIZE) MANHOLES CATCH BASINS AND DITCH INLETS -Item No.
ADJUSTING AND REBUILDING MANHOLES, CATCH BASINS AND DITCH INLETS
- Item No.
Special Provision No. 407S06
April 2014
Amendment to MTC Form 407, March 1984
Aggregate Requirements, Lift Rings, Adjustment Units and Resilient Connectors
407.02
REFERENCES
Section 407.02 of MTC Form 407 is amended by the addition of the following under Ministry Material
Specifications:
OPSS 1854
407.03
Material Specification for High Density Polyethylene (HDPE) and Expanded Polystyrene
(EPS) Adjustment Units for Maintenance Holes, Catch Basins, and Valve Chambers
DEFINITIONS
Section 407.03 of MTC Form 407 is amended by the addition of the following:
Adjustment Units means circular and rectangular units used between the structure and the frame to adjust the
elevation of the frame for grates and covers.
Lift Rings means circular and rectangular prefabricated units used to adjust the elevation of the grates and
covers only. They are inserted between the frame and the grates or covers.
407.05
MATERIALS
407.05.02
Precast Reinforced Concrete Manholes, Catch Basins, and Ditch Inlet
Components for Both Precast Concrete Units, and Corrugated Steel Pipe Units
Subsection 407.05.02 of MTC Form 407 is deleted in its entirety and replaced by the following:
Precast concrete units shall be according to OPSS 1351 amended as follows:
1351.02
REFERENCES
Section 1351.02 of OPSS 1351, is amended by the addition of the following under American Society
for Testing and Materials:
ASTM C 923 - 00 - Standard Specification for Resilient Connectors Between Precast Reinforced
Concrete Manhole Structures, Pipes and Laterals
1351.05
MATERIALS
Section 1351.05 of OPSS 1351 is amended by the addition of the following subsection:
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1351.05.11
Resilient Connectors
Resilient connectors shall conform to the requirements of ASTM C 923 M - 89.
407.05.07
Adjustment Units
Subsection 407.05.07 of MTC Form 407 is deleted in its entirety and replaced with the following:
407.05.07.01
Precast Concrete Adjustment Units
Precast concrete adjustment units shall be according to OPSS 1351 as amended in this Special Provision.
407.05.07.02
Prefabricated Recycled Rubber Adjustment Units
Prefabricated recycled rubber adjustment units shall be according to the following requirements:
Durometer Hardness
Tensile Strength
Compression Deformation
Compression Set
407.05.07.03
maximum 15 Shore A variance
1 MPa minimum
6% +/- 2%
4% maximum
High Density Polyethylene (HDPE) and High Density Expanded Polystyrene
(EPS) Adjustment Units
High density polyethylene and high density expanded polystyrene (EPS) adjustment units shall be according
to OPSS 1854.
407.05.08
Frames, Grates, Covers and Lift Rings
Subsection 407.05.08 of MTC Form 407 is deleted in its entirety and replaced by the following:
Metal frames, grates, covers and lift rings shall be according to OPSS 1850.
Plastic lift rings shall be made of high density polyethylene and shall be according to the loading
requirements of OPSS 1850.
407.07.07
Installation of Inlet or Outlet Pipe
407.07.07.01
Concrete, Clay or Plastic Pipe
Clause 407.07.07.01 of MTC Form 407 is amended by the addition of the following paragraph:
Resilient connectors, installed according to the manufacturer's instructions, may be used to connect inlet and
outlet pipes to concrete drainage structures.
407.07.09
Installation of Frames, Grates or Covers
Subsection 407.07.09 of MTC Form 407 is deleted in its entirety and replaced by the following:
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The manholes and catch basins shall be constructed or installed so that the surface on which the bricks or
adjustment units are to be placed is at least 75 mm but not more than 150 mm below the bottom of the frame
and grate or cover assembly.
Any combination of bricks, precast concrete adjustment units and rubber adjustment units may be used to set
the frames and grates/covers on manholes and catch basins at the required position and elevation.
A minimum of one rubber adjustment unit shall be used in all installations where the frame and grate/cover is
located within the driving area of the pavement. The total height of the rubber adjustment unit(s) must be
greater than 25 mm and less than 75 mm.
Rubber adjustment units can be used in combination with concrete adjustment units or brick; the rubber
adjustment unit must form the final surface for the seating of the frame and grate/cover assembly. Bricks or
concrete adjustment units must not be placed on top of rubber adjustment units.
Rubber adjustment units shall be bonded to adjacent surfaces by laying a continuous strip of butyl tape on the
top surface of the concrete adjustment units or brick course. The rubber adjustment unit shall be seated firmly
in place, ensuring that it is centred over the structure opening. If more than one rubber unit is used, a
continuous strip of butyl tape is to be laid between each rubber adjustment unit. A continuous strip of butyl
tape shall be applied to the top surface of the rubber adjustment units and to the bottom of the frame. The
frame shall then be set firmly in place ensuring that it is properly centred over the structure opening.
HDPE and high density EPS adjustment units shall be installed and sealed according to manufacturer’s
recommendations.
If only brick or concrete adjustment units are used, or any combination of both, the frames for grates and
covers on manholes and catch basins shall be set in a full mortar bed.
If bricks are used, the inside and outside surfaces of the bricks shall be parged with a 12 mm thick mortar
coat.
Gratings for ditch inlets shall be installed and fastened down as specified in the contract.
Frames and grates which are within the flow lines of the curb and gutter system shall be installed in
accordance with OPSS 353 and shall not be part of the work of constructing cast-in-place manholes or catch
basins or supplying and installing precast manholes and catch basins.
407.07.11
Adjustment and Rebuilding of Manholes, Catch Basins and Ditch Inlets
407.07.11.01
General
Clause 407.07.11.01 of MTC Form 407 is deleted in its entirety and replaced by the following:
The work to be carried out shall include changes of elevation of any of the above structures, regardless of type
or size.
Prior to adjustment or rebuilding, the existing frame and grate/cover, lift rings and rubber adjustment units
shall be removed and salvaged. When salvaged components are in reusable condition, they shall be cleaned
of all mortar, sealants, rust and dirt. The manhole, catch basin or ditch inlet shall be adjusted or rebuilt using
these salvaged components; otherwise, new components shall be installed so that the frame and grate/cover is
set to the correct elevation.
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When manhole covers are to be raised only to accommodate resurfacing of the adjacent pavement, the
Contractor may use manhole cover lift rings to raise the manhole grate or cover a sufficient height to
accommodate the thickness of resurfacing material. Lift rings may be placed on top of each other to a
maximum height of 140 mm. Only one type of lift ring or lift device shall be used for each structure.
Bricks may be used to raise structures by a maximum of 300 mm which includes any extension of structures
previously constructed using bricks. The inside and outside surfaces of the bricks shall be parged with a
12 mm thick mortar coat.
Precast concrete adjustment units may be used to raise structures a maximum of 1.0 m which includes the
extension of structures previously constructed using precast concrete adjustment units or a combination of
bricks and precast concrete adjustment units.
A minimum of one rubber adjustment unit shall be used in all installations where the frame and grate/cover is
located within the driving area of the pavement. The total height of the rubber adjustment unit(s) shall be
greater than 25 mm and less than 75 mm, which includes any extension of structures previously constructed
using rubber adjustment units.
The maximum total extension of structures shall not exceed 1.0 m which includes any extension of structures
previously constructed using any combination of adjustment units and bricks.
All existing mortar and brickwork shall be removed from the top of the existing structures prior to adjustment
or rebuilding with adjustment units.
Additional manhole steps shall be required when the distance from the adjusted elevation of the structure to
the first step would be in excess of 0.6 m.
Where bituminous or concrete pavement must be removed to adjust or rebuild a structure, the pavement shall
be removed according to OPSS 510.
407.07.11.02
Cast-in-Place Units
Clause 407.07.11.02 of MTC Form 407 is amended by deleting the three paragraphs under "Adjustment" and
replacing them with the following:
The adjustment of manholes, catch basins, or ditch inlets by raising will apply where the tops are to be raised
by 1.0 m or less.
The adjustment of manholes, catch basins, or ditch inlets by lowering will apply when the tops may be
lowered to the required elevation by the removal of bricks, the removal of adjustment units, the removal of
the mortar bed in which the frame was set, and by the removal of a maximum of 50 mm of the concrete walls
of the structures.
Where tops are to be lowered, the concrete shall be carefully removed to the required elevation.
407.07.11.03
Precast Units
Clause 407.07.11.03 of MTC Form 407 is amended by deleting the three paragraphs under "Adjustment" and
replacing them with the following:
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The adjustment of precast manholes, catch basins, or ditch inlets by raising will apply where the tops are to be
raised by 1.0 m or less.
The adjustment of manholes, catch basins, or ditch inlets by lowering shall only apply where the tops may be
lowered to the required elevation by the removal of bricks, the removal of adjustment units, and the removal
of the mortar bed in which the frame was set.
Adjustment units, bricks or manhole cover lift rings shall be removed or added as required, to adjust the
structure to the proper elevation.
Subsection 407.07.11 of MTC Form 407 is amended by the addition of the following clause:
407.07.11.04
High Density Polyethylene (HDPE) and High Density Expanded Polystyrene
Adjustment Units
HDPE or high density EPS adjustment units may be used to set the frame with grate or cover at the required
position and elevation up to a maximum height of 100 mm where a minimum of one adjustment unit is
required at each structure.
HDPE and high density EPS adjustment units shall be installed and sealed according to manufacturer’s
recommendations.
Rubber adjustment units shall not be used in conjunction with HDPE or high density EPS adjustment units.
407.10
BASIS OF PAYMENT
407.10.01
Manholes, Catch Basins and Ditch Inlets
Subsection 407.10.01 of MTC Form 407 is deleted in its entirety and replaced by the following:
Payment at the contract price for the various tender items, "Manholes, Catch Basins and Ditch Inlets" shall be
full compensation for all labour, equipment, and materials; for all earth excavation; for the removal of
pavement, curb and gutter, and sidewalk except where there is a separate item for removal of pavement, curb
and gutter, and sidewalk which overlaps pavement, curb and gutter and sidewalk removal required for
placement of manholes, catch basins, and ditch inlets; for the management of surplus excavated materials; for
the placing and compacting of granular bedding and backfill; for the construction or installation of the
cast-in-place, precast or corrugated steel pipe units, and for the installation of inlet and outlet pipe, for the
installation of concrete manhole tees with concrete risers, for the installation of corrugated steel pipe
manholes with saddle plates and corrugated steel pipe risers and sewers larger than riser; for the installation of
the frame and grate or frame and cover; for the placing of the full mortar bed; for the placing and parging of
bricks; for the application of butyl tape; and the placing of adjustment units; except where such installations
are part of the work of constructing curb and gutter and for all other work necessary to complete the structure
in accordance with the contract.
407.10.02
Adjusting and Rebuilding Manholes, Catch Basins and Ditch Inlets
Subsection 407.10.02 of MTC Form 407 is deleted in its entirety and replaced with the following:
Payment at the contract price for the tender item "Adjusting and Rebuilding Manholes, Catchbasins, and
Ditch Inlets" shall be full compensation for all labour, equipment, and materials for the removal and
management of bituminous or concrete pavement where required, for all necessary excavation, including
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removal of any concrete and management of surplus excavated material, for handling, placing, and
compacting of backfill materials, for salvaging and installing the salvaged or new frame and grate or cover,
for all protection required against the elements, and for all other items of work necessary for the satisfactory
completion of the work, except for the removal of asphalt or concrete curb and gutter, which work shall be
paid for at the contract price(s) for the item(s) concerned.
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