RomânăBSC-Resistant Linings for Sewers & Manholes
Concrete sewers and manholes represent the most extensive and most severely deteriorated elements of urban water infrastructure. Biogenic sulphuric acid (BSC) corrosion destroys unprotected concrete in severe conditions at 10-30mm per year - turning the crown and upper walls of sewers into fragile chalky material within a decade of service. Manholes are particularly vulnerable: their confined geometry concentrates H₂S gas, and the repeated entry of maintenance personnel requires structural integrity that BSC rapidly compromises. Gemite's BSC-resistant lining systems - applied by spray or hand application in man-entry sewers and manholes - provide decades of additional service life to deteriorated infrastructure.
Sewer & Manhole Rehabilitation Applications
Man-Entry Sewer Rehabilitation
For sewers large enough for confined space entry (typically DN 800mm and above), hand-applied spray lining provides flexibility to rehabilitate non-circular sections, repair structural defects, and inspect the applied lining quality. Gemite's spray-applied BSC-resistant systems achieve the thickness, continuity, and surface quality required for long-term acid resistance in the complex internal geometry of man-entry sewers - including benching, channels, and structural repair areas.
Manhole Rehabilitation
Manholes are the access points to the sewer network - subject to H₂S attack from the sewer below, impact from maintenance equipment, and in some cases, root penetration through joints and cracks. Rehabilitation of deteriorated manholes involves: structural repair of the concrete rings, sealing of leaking joints and connections, and application of a BSC-resistant lining to all internal surfaces. Gemite provides a complete manhole rehabilitation system - from injection repair of active leaks through final protective coating - as a single-source technical package.
Key Performance Characteristics
BSC Resistance at pH 1-2
Geopolymer and acid-tolerant polymer-modified cementitious linings that resist the biogenic sulphuric acid produced in the sewer headspace - providing decades of service where standard Portland cement fails within years.
Root Penetration Resistance
Dense lining systems that resist root penetration through sewer joints - preventing the structural damage and infiltration caused by root ingress in sewers running through planted or vegetated areas.
Grease Resistance
Sewer linings in food service drainage zones resist grease and organic acid attack from restaurant and food processing effluent - preventing the surface fouling that accelerates BSC attack.
Man-Entry & Remote Application
Systems available for both man-entry spray application (large sewers and manholes) and remotely-operated Spin-Cast application (non-man-entry pipe sizes) - covering the full range of sewer diameters requiring rehabilitation.
Sewers & Manholes - Technical Questions
How do you rehabilitate a manhole affected by BSC without replacing it?
Manhole rehabilitation is performed in-situ by: (1) bypassing flow from the connected sewer; (2) gas-freeing and ventilating the manhole; (3) high-pressure jetting to clean all surfaces; (4) injection of active leaks with hydrophilic polyurethane grout; (5) repair of spalled and deteriorated concrete with Gemite's repair mortars; (6) re-profiling of the benching and channel if required; (7) spray application of the BSC-resistant lining to all internal surfaces in the specified thickness; (8) inspection and holiday testing; (9) return to service. The complete process takes 1-3 days per manhole depending on size and condition. No excavation is required - all work is performed from the manhole surface level.
Can sewer lining be applied to brick manholes and sewers?
Yes - brick construction is a substrate compatible with Gemite's lining systems. Brick sewers and manholes require surface preparation (high-pressure jetting, degreasing, and in some cases, removal of deteriorated mortar from joints) before lining application. The lining provides a smooth, continuous surface over the brick fabric, sealing joints and preventing water infiltration through the mortar. Old brick sewers often have significant joint deterioration and root intrusion - injection repair of active leaks before lining is particularly important in brick construction to ensure lining continuity.
What is the minimum sewer diameter that can be rehabilitated with Gemite's systems?
For man-entry systems, the minimum practical diameter for confined space lining work is DN 800-900mm. For remotely operated Spin-Cast systems, rehabilitation is feasible from DN 150mm. Sewers from DN 150mm to DN 700mm are typically rehabilitated by Spin-Cast (trenchless, from manhole access). Sewers from DN 800mm and above can be rehabilitated by either Spin-Cast or man-entry spray application - with man-entry preferred for complex geometries, structural repairs, or where inspection of the applied lining is required. Our technical team recommends the appropriate method for the specific pipe diameter and condition.
Rehabilitating Sewers or Manholes?
Our specialists design the complete sewer and manhole rehabilitation programme - BSC-resistant lining, structural repair, joint sealing, and bypass management - as a single-source technical package.
- BSC exposure and deterioration assessment
- Lining system selection and thickness specification
- Active leak injection protocol
- Post-lining inspection and holiday testing
Or contact us: office@gemite.tech · +40 232 273 031