What Does
Chimney Seal Mean?
Chimney seals are installed in sanitary manholes for the purpose of keeping infiltrating water from entering the manhole. A durable material is used to provide a seal within the manhole frame that firmly keeps the manhole top in place while making it watertight.
Chimney seals are available as both external and internal seals and are available in different application types, such as epoxy internal chimney seal, heat applied sheeting external chimney seal and rubber sleeve internal chimney seal.
Trenchlesspedia Explains Chimney Seal
Inflow/infiltration (I/I) can be prevented by using chimney seals in manholes. Storm water runoff and surface water during rainy season can easily find their way into manholes, posing flooding problems during excessive rainfall.
In the epoxy internal chimney seal, the area to be sealed is sandblasted and then cleaned of dust and dried. Primer is applied up to 2″ above and below the area to be sealed and epoxy is applied in two parts.
In heat applied sheeting external chimney, the area to be sealed is cleaned of debris and dried. The required size of sheeting with overlap is cut and stuck in the area after which a propane torch is used to dry and set the sheet in place. A primer is applied on the sheet over which the second sheet is wrapped and heated untill the desired bond is achieved.
In the rubber sleeve internal chimney seal, the correct size of rubber sleeve based on the manhole diameter is procured. The area to be sealed is cleaned well and smoothed to ensure a good seal. Steel clamp bands are installed in the recesses and tightened.