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SEI Interlocking Trench Sheets

SEI Interlocking Trench Sheets

Heavy-duty interlocking steel sheets designed to control groundwater and support excavations

  • 6.0mm thick interlocking profile
  • Ideal for water-bearing ground
  • Creates a continuous, linked barrier
  • Compatible with waler and frame systems
  • 36.0 kNm/m allowable bending moment
  • Delivered nationwide

SEI Interlocking Trench Sheets are 6.0mm thick heavy-duty steel profiles designed specifically for excavations where groundwater ingress is a challenge. Available for sale or hire, their interlocking mechanism creates a continuous, linked wall that significantly outperforms standard lapped sheets in retaining soil and managing water.

Unlike standard overlapping sheets which merely rest against each other, SEI sheets physically link together along their longitudinal edges. This continuous interlock provides maximum structural support and creates a far tighter barrier against groundwater and fine soil seepage, making them an essential component for drainage, sewerage, and medium-depth civil engineering works in difficult ground conditions.

Typical applications

  • Excavations with high groundwater tables
  • Sewerage, pipeline and drainage installations
  • Riverbank and coastal protection works
  • Cofferdams and retaining walls
  • Shafts and pit excavations
  • Medium-to-heavy temporary groundwork support

Integration with shoring systems

Once pitched and driven, SEI interlocking sheets act as the primary earth-retaining face. To support the lateral loads, they are routinely used in conjunction with "sheet and frame" shoring setups. They work perfectly alongside our Aluminium Waler Frames or heavier structural H-Series Bracing.

Because they provide a continuous linked wall, the loads are distributed more evenly into the waler rails than with individual lapped sheets, offering a highly secure and stable excavation environment. Corner piles are also available upon request to cleanly close off square or rectangular pit excavations.

SEI Sheets: Common Questions

What is the difference between SEI interlocking sheets and standard lapped sheets?
The primary difference is the edge profile. SEI interlocking sheets feature edges that physically slot and lock into the adjacent sheet, creating a continuous, linked steel wall. Standard lapped sheets only overlap and rest against each other, which provides less structural integrity and allows more groundwater to seep through.
Why use SEI sheets in water-bearing ground?
SEI sheets should be used in water-bearing ground because their continuous interlocking design creates a tight barrier that significantly reduces the ingress of groundwater and prevents fine, saturated soil from washing into the excavation.
What are the dimensions of an SEI trench sheet?
An SEI trench sheet is 535mm wide (providing an effective driven width of 508mm), 75mm deep, and has a steel thickness of 6.0mm. It weighs 33.5 kg per metre.
How strong is an SEI interlocking trench sheet?
An SEI interlocking trench sheet provides an allowable bending moment of 36.0 kNm/m, making it a robust, heavy-duty option for medium-depth excavations and difficult ground conditions.
How are SEI trench sheets installed?
SEI trench sheets are typically installed using an excavator equipped with a driving cap (the push and dig method) or an EMV (Excavator Mounted Vibrator) piling hammer. The sheets are pitched vertically and the interlocking edge is threaded into the previously driven sheet before being pushed or vibrated down.
Can SEI sheets be used to form corners?
Yes, corner piles are available to be used alongside SEI sheets. These allow you to maintain the continuous interlocking seal through 90-degree turns when constructing square or rectangular cofferdams and pits.

Buy or Hire SEI Interlocking Trench Sheets

We offer SEI interlocking trench sheets for sale or hire with excellent stock availability, fast lead times, and competitive rates. Our team can also supply EMV piling hammers, corner piles, and compatible bracing systems. Contact your nearest depot or call us on 0117 982 8236 to discuss your project requirements.

SEI sheet specifications

Key Dimensions & Capacity
Width535 mm
Effective Width508 mm
Depth75 mm
Thickness6.0 mm
Weight Per Metre33.5 kg/m
Weight Per Square Metre67.0 kg/m²
Allowable Bending Moment36.0 kNm/m

For lighter applications, view our Standard or BD500 overlapping sheets. For heavy-duty 8.0mm profiles, see our KD6 sheets.

SEL Trench Sheets Information Sheet

Questions? Talk to SEL about SEI Sheets

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Compatible bracing systems and alternative trench sheets

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