3.05
materials handling, mixing, environmental controls, working time, working temperature,
pot life, allowable time between coats (recoat time), safety, and spray equipment. A
permanent identification and date of work performed shall be affixed to the structure in a
readily-visible location, and a final written report shall be provided to Owner and
Engineer detailing the location, date of report, and description of liner installation.
Epoxy or polyurethane coating shall be installed in strict accordance with the
manufacturer’ s installation instructions, including those for materials handling, primers,
mixing, environmental controls, working time, working temperature, pot life, allowable
time between coats (recoat time), safety, and soray equipment. Installation of epoxy or
polyurethane coating over cementitious base coat shall not occur until the cementitious
base coat has cured to the extent and time required by the manufacturer. A permanent
identification and date of work performed shall be affixed to the structure in a readily-
visible location, and a final written report shall be provided to Owner and Engineer
detailing the location, date of report, and description of liner installation.
Cementitious base coat shall be installed in strict accordance with the manufacturer’s
installation instructions, including those for materias handling, on-site mixing,
e€nvironmenta controls, working time, working temperature, safety, and soray equipment.
Water shal only be added to the materials during the mixing process and prior to materia
pumping or soray application; water shall not be added a& the nozzle Cementitious base
coat shall only be installed via low-pressure application. The cured base coat surface shall
be trowded smooth and continuous with proper sealing connections to all unsurfaced areas.
The total thickness of the cementitious base coat shall be in accordance with the eooxy or
polyurethane lining menufacture’'s recommendations and the following minimum
requirements:
1. For all brick manholes and for block or cast concrete manholes in poor
condition with notable loss of surface material or exposed reinforcing, apply to a
minimum thickness of 1 inch.
2. For block or cast concrete manholes in fair condition, aoply to a minimum
thickness of 0.5 inch.
3. For block or cast concrete manholes in good condition with no loss of
surface material, it may be acceptable to aoply the epoxy or polyurethane top coat
directly to the manhole surface without applying a cementitious base coat if the
Contractor confirms that the existing manhole surface meets the requirements of
the epoxy or polyurethane top coat manufacturer.
BENCH, CHANNEL, AND INVERT:
Flow channels shall conform in shape and slope to that of the existing sewers entering and
exiting the manholes.
Invert shall be smooth, shall be semi-circular in cross-section, and shal have the sane
diameter as the existing pipe exiting the manhole.
02800-7
