About MC-Bauchemie Konudur 250 OM-PL Sommerharz

Konudur 250 OM-PL Sommerharz is the summer-grade resin in MC-Bauchemie’s OMBRAN short-liner system — a trenchless, “no-dig” method for repairing underground sewer and storm-water pipes that are too small, too deep, or too live to excavate. It’s a two-component organic-mineral resin (Component A and B, mixed 1:2 by volume) used to impregnate ECR glass-fibre patches, which a technician then positions on a packer, inflates against the defect from inside the pipe, and holds under pressure while the resin cures into a hard, bonded structural patch. “Sommerharz” simply means MC-Bauchemie tuned this particular batch chemistry for warmer working conditions — application is rated between +10°C and +30°C air and substrate temperature — with a companion Winterharz grade formulated for colder sites, so pot life and cure speed stay predictable whatever the season.

In practice this is a specialist product, not a shelf item — sewerage boards, industrial estates, and utility contractors bring it in for a specific short-liner or patch-liner job, typically alongside MC-Bauchemie’s general application-advice sheets for the system, the matched Beschleuniger accelerator, and MC-Cleaner U for tooling. Space Arc supplies it on that same project basis for Delhi NCR and pan-India underground-infrastructure work, and can coordinate a trained applicator crew, since MC-Bauchemie’s own datasheet is explicit that hand-mixing this resin is not permitted — it has to go through a slow mechanical stirrer or static mixer for a full three minutes to get the void-free consistency the glass-fibre laminate needs.

The technical insight

The organic-mineral hybrid chemistry is what makes this a “resin,” not an epoxy: it’s engineered specifically to fully wet out ECR glass fibre at a low, controlled viscosity so the cured laminate is dense and void-free rather than resin-starved. Cure kinetics follow MC-Bauchemie’s stated rule of thumb — every 10°C change roughly doubles or halves pot life and cure time — which is exactly why the product exists in two grades. Sommerharz’s chemistry is tuned so that at +20-30°C summer pipe temperatures it doesn’t flash-cure before the glass-fibre patch can be positioned and inflated on the packer, while still setting fast enough (pot life as short as ~33 minutes at +20°C) to keep a repair crew’s cycle time reasonable. The compressive (~40 MPa) and tensile (~13 MPa) figures, tested to DIN EN ISO 604 and 527, describe the cast resin itself — the actual strength of a short-liner patch in a live pipe also depends on fibre loading, packer pressure, and workmanship, so these numbers are a material benchmark rather than a guaranteed in-situ result.

Where it is used

• Impregnating ECR glass-fibre patches for OMBRAN short-liner (patch-liner) point repairs in non-accessible sewer pipes
• No-dig, trenchless rehabilitation of cracked, holed, or joint-displaced sewer and storm-water pipes
• Localised repair of lateral house-connection junctions using hat-profile short liners
• Structural patching of defective sections in municipal sewer and drainage networks
• Point repairs in underground industrial effluent and process-drainage pipelines
• Summer/warm-season rehabilitation campaigns where ambient and pipe temperature sit within the +10 to +30°C working window
• Utility-contractor short-liner projects under live roads, buildings, or infrastructure where full pipe replacement isn’t practical
• Combined use with Konudur 250 OM-PL Beschleuniger accelerator when a job needs a shorter working/cure window

Key advantages

• Trenchless (no-dig) repair avoids excavation, road-cutting, and reinstatement costs of a conventional open-cut sewer dig-up
• Low-viscosity resin (approx. 480-533 mPa·s) wets out ECR glass fibre thoroughly for a dense, void-free laminate
• Good documented adhesion to concrete, brick, and ceramic/vitrified-clay pipe substrates
• Can be applied to damp mineral surfaces, a realistic condition inside a live or recently jetted sewer line
• Summer-specific formulation keeps pot life and cure predictable in Indian ambient/pipe temperatures instead of flash-curing
• Verifiable mechanical data on the sheet — approx. 40 MPa compressive and 13 MPa tensile strength to DIN EN ISO 604/527 — not vague marketing claims
• Reaches full chemical and mechanical service load in about 7 days, so the line can be returned to service quickly
• Part of a complete, engineered OMBRAN system (matched accelerator, cleaner, fibre, application-advice sheets) rather than an improvised standalone resin

Limitations & considerations

• Strictly a two-component reactive resin — hand-mixing or mixing partial packs is expressly disallowed; needs a mechanical stirrer/static mixer and a trained crew
• Narrow rated application window (+10°C to +30°C air/substrate); outside that range the Winterharz grade or accelerator adjustment applies instead
• Pot life is short and temperature-sensitive (as little as ~33 minutes at +20°C) — a 10°C swing roughly halves or doubles it, so batching and site logistics need tight planning
• A specialist OMBRAN-system product for underground pipe rehabilitation, not a general concrete repair mortar — in India it’s supplied on a project/import basis rather than off a distributor shelf
• Strength figures on the datasheet (approx. 40 MPa compressive, 13 MPa tensile) are for the pure cast resin, not the finished in-situ glass-fibre laminate, whose real performance also depends on fibre content and packer pressure
• As a reactive 2K resin (GISCODE PU40) it carries standard skin/respiratory handling precautions during mixing and application

Selection & best practice

Specifications

Industry use cases

How we position MC-Bauchemie Konudur 250 OM-PL Sommerharz

Within MC-Bauchemie’s own OMBRAN range, Konudur 250 OM-PL Sommerharz pairs with the Winterharz grade (cold-weather chemistry for the same system), the Beschleuniger accelerator (for faster turnarounds), ECR glass-fibre patch material, and MC-Cleaner U for tooling — the four are meant to be specified together, not swapped from other suppliers. It sits apart from MC-Bauchemie’s mainstream building-repair range (Nafufill and Emcekrete mortars, which Space Arc also stocks) because it solves a different problem: trenchless pipe rehabilitation rather than structural concrete repair.

There is no genuine Fosroc equivalent to flag here. Fosroc’s Indian portfolio (Renderoc, Nitomortar, Conbextra, Nitoproof) is built around concrete repair, grouting, and waterproofing — it does not carry a comparable glass-fibre-impregnation resin for OMBRAN-style short-liner sewer rehabilitation, so this isn’t a category where a brand swap genuinely applies. Specifiers comparing options here are really comparing trenchless-system providers (and their proprietary resin/liner chemistry) rather than choosing between equivalent SKUs.

Related Concrete Repair products

View all Concrete Repair products →