FAQ

Slot Block Barrier - Water-filled Base and Stabiliser for 3.5m Fence Panels

The Slot Block Barrier is a water-filled HDPE base used to slot, hold and ballast standard 3.5m x 2m temporary fence panels on hard-standing surfaces. Two units are required per panel. One unit is placed at each end of the panel, the fence panel posts drop into the housing on each base, and both units are filled with water on site. Once filled, each unit weighs 160kg. The pair provides 320kg of ballast across the 3.5m set.

No separate fence feet, backstays or ground anchoring is required. Both units can be positioned by hand at 14kg unfilled, then filled from a water source on site. Once filled, mechanical handling is needed to move a set. The 600mm base height and the red and white colour split provide clear visual demarcation along the fence line.

The Slot Block Barrier sits alongside the ROTA Slot in the Securasite water-filled fence base range. The ROTA Slot is a single 3500mm unit that spans the full panel width at 300mm height, with safety bolt fastening. The Slot Block uses two units at 1750mm each and stands at 600mm height. Both products are designed for standard 3.5m x 2m panels. Speak to our team on 0330 056 4420 if you need guidance on which suits your site.

Key Features

Water-filled HDPE base integrates ballast and panel support into a single unit. No separate fence feet or loose ballast blocks are needed alongside the Slot Block. The fence panel posts slot directly into the base housing.
320kg combined filled weight per set. Water is added on site from any available source. Both units filled provide ballast across the full 3.5m panel position without separate weights placed alongside.
14kg per unit unfilled. Each unit can be carried and positioned by hand before filling. Once both units are filled, the set weighs 320kg and requires mechanical handling to move.
Two units required per panel. One at each end of the panel. For a 10-panel run, you need 20 units (10 sets). Check quantities before ordering.
90° rotation for corners and enclosed layouts. Units can be turned at the end of a fence run to create corners or to box off a restricted zone without specialist corner connectors.
Approx. 2050mm assembled height with fence panel. The base stands at 600mm. With a standard 2m fence panel slotted into the housing, the combined visible height from ground level is approximately 2050mm.
HDPE construction, 100% recyclable. Manufactured from HDPE. Fully recyclable at end of service life.

What You Receive

Variation 1: Red and White pair (SLOT-BLOK-RED-WHT)

1 x Red Slot Block unit, 1750mm x 380mm x 600mm, 14kg unfilled
1 x White Slot Block unit, 1750mm x 380mm x 600mm, 14kg unfilled
Not included: Fence panels, fence couplers, water supply

Variation 2: Red and White pair with 3.5m fence panel (SLOT-BLOK-WHT-RED-CW-FENCE)

1 x Red Slot Block unit, 1750mm x 380mm x 600mm, 14kg unfilled
1 x White Slot Block unit, 1750mm x 380mm x 600mm, 14kg unfilled
1 x 3.5m x 2m temporary fence panel (TF-30-RT-001-PGA)
Not included: Fence couplers for panel-to-panel connections, water supply

Two units are always required per fence panel. If ordering the pair-only variation to extend an existing run, order one set per additional panel position.

Specification	Detail
Unit length	1750mm
Unit height	600mm
Assembled height (with fence panel)	Approx. 2050mm
Unit depth	380mm
Weight per unit (unfilled)	14kg
Weight per unit (filled)	160kg
Weight per set (both units filled)	320kg
Units required per 3.5m fence panel	2 (one at each end of the panel)
Compatible panel size	Standard 3.5m x 2m temporary fence panels
Rotation	90°
Material	HDPE
Recyclability	100% recyclable
Colours	Red and White (supplied as pair)

Variation	Product Code	Supplied With	Not Included
Red and White pair	SLOT-BLOK-RED-WHT	1 x Red unit (1750mm), 1 x White unit (1750mm)	Fence panels, fence couplers, water supply
Red and White pair with 3.5m fence panel	SLOT-BLOK-WHT-RED-CW-FENCE	1 x Red unit (1750mm), 1 x White unit (1750mm), 1 x 3.5m x 2m fence panel.	Fence couplers for panel-to-panel connections, water supply

Application Suitability Guide

The table below covers common applications for the Slot Block Barrier. Where a use case is marked as confirm before use, speak to our team before ordering.

For reference only, not legal advice. Always carry out your own site risk assessment before use.

Application	Suitable	Why It Fits	Caution or Better Option
Construction sites (tarmac, concrete, paved hard-standing)	Yes	Designed to accept standard 3.5m fence panels without ground anchoring. Units are filled on site from any water source.	Confirm water source availability before ordering. Once filled, the set requires mechanical handling to reposition.
Civil engineering and utility works (hard-standing)	Confirm before use	No ground anchoring needed on paved surfaces. Water filled on site.	Carry out your own site risk assessment. Confirm suitability with your project team before ordering.
Event perimeter fencing on hard-standing	Confirm before use	No ground fixing needed. Water source required on site.	Confirm with your event safety plan and venue requirements before ordering.
Highway and roadwork demarcation near live traffic	Confirm before use	Provides water ballast without ground fixing on highway surfaces.	Traffic management plans and barrier specification for highway use must be confirmed with your traffic management team before ordering.
Soft, uneven or grass ground	Not suitable	The Slot Block requires a firm, level surface to sit correctly and support the panel housing.	For soft or uneven ground, consider rubber fence feet with ballast blocks or the Fence-Lok system where ground anchoring is available.
Fence runs with debris netting or vented sheeting	Confirm before use	The 320kg filled set provides more ballast than standard rubber feet.	Attaching netting or sheeting to panels increases wind loading on the fence run and the base. Confirm adequacy with your site engineer before ordering.
Fence runs with acoustic panels	Confirm before use	Acoustic panels add weight and surface area to the fence run.	Confirm wind load compatibility with your site engineer. Call us on 0330 056 4420 to discuss this application.

Compatibility and Accessory Guide

Fence couplers are required for any multi-panel run and are not included in either variation. Fence panels are required unless the pair-with-fence-panel variation is ordered. Contact our team on 0330 056 4420 to confirm the right accessories before placing your order.

Item	Status	Why It Matters	Notes
Standard 3.5m x 2m temporary fence panels	Required (unless pair-with-panel variation ordered)	The Slot Block is designed to accept standard 3.5m x 2m fence panels. A panel is needed at every set position.	Included in SLOT-BLOK-WHT-RED-CW-FENCE. Sold separately with SLOT-BLOK-RED-WHT.
Standard fence couplers (AC-TF-CS-01)	Required	Needed to connect fence panels to each other at every join along the run. Not included in either variation.	Two couplers typically required per panel join. Order alongside your Slot Block sets.
Lockable fence couplers (AC-TF-CPS-01)	Optional	Tamper-resistant panel connections for secure or restricted access sites.	Requires anti-tamper coupler spanners (AC-TF-CSD-02) for removal.
Debris netting or vented sheeting	Caution	Adding netting or sheeting to panels increases wind loading on the fence run and the base.	Confirm ballast adequacy for your wind class and panel configuration with your site engineer before attaching any sheeting or netting.
Reflective strips	Optional.	Increases visibility of the fence line in low-light conditions.	Confirm availability

Alternative Products to Consider

Product	What It Does Differently	When to Consider It Instead
ROTA Slot	Single 3500mm unit that spans the full panel width at 300mm height. 304kg when filled. Safety bolt fastening. One component per panel position rather than two.	Where a lower-profile base is needed, where a single full-width unit suits the site layout, or where safety bolt fastening is required. Speak to our team if you are unsure which to choose.
Standard rubber fence feet (thermoplastic)	Lightweight single-piece foot. Lower cost per panel position. No water ballast. Separate ballast blocks needed if additional weight is required.	On sheltered sites where basic footing with separate ballast is acceptable. Not where a water-ballasted, higher-load or integrated base is needed.
Fence-Lok system	Ground-penetrating anchored bracket for soil, concrete and tarmac. No water required. Locked and anchored to the surface.	Where ground anchoring is available and a fixed, anchored perimeter is preferred over water ballast.

Frequently Asked Questions

How many Slot Block Barrier units do I need per fence panel?

Two units are required per panel. One is placed at each end of the 3.5m panel. Each set on this page (SLOT-BLOK-RED-WHT or SLOT-BLOK-WHT-RED-CW-FENCE) contains one Red unit and one White unit, which covers one panel position. For a 10-panel run, you need 10 sets (20 units total). Call us on 0330 056 4420 and we can help you work through your quantities before ordering.

What fence panels are compatible with the Slot Block Barrier?

The Slot Block Barrier is designed for standard 3.5m x 2m temporary fence panels. The panel posts slot directly into the housing on each base unit. We supply a range of 3.5m x 2m fence panels including round top, premium and HD universal versions. Contact our team to confirm which panel type is right for your site before ordering.

Are fence panels included in the set?

It depends on the variation you order. The Red and White pair (SLOT-BLOK-RED-WHT) includes the two Slot Block base units only. Fence panels are sold separately. The Red and White pair with fence panel (SLOT-BLOK-WHT-RED-CW-FENCE) includes both base units plus one 3.5m x 2m fence panel. Fence couplers for connecting panels along the run are not included in either variation.

How much does the Slot Block Barrier weigh once filled, and do I need mechanical handling?

Each unit weighs 14kg unfilled and can be positioned and moved by hand before filling. Once filled, each unit weighs 160kg and the pair weighs 320kg combined. A set at full weight requires mechanical handling to reposition. Plan your site layout before filling. Call us on 0330 056 4420 if you need guidance on site deployment planning for larger runs.

Can the Slot Block Barrier be used on soft ground, grass or uneven surfaces?

No. The Slot Block Barrier is designed for firm, level hard-standing surfaces such as tarmac, concrete and paving. It requires a flat base to sit correctly and support the panel housing. For soft ground, uneven terrain or grass, standard rubber fence feet with additional ballast or the Fence-Lok ground-anchored system are more appropriate. Call us on 0330 056 4420 to confirm the right product for your ground conditions.

What is the difference between the Slot Block Barrier and the ROTA Slot?

Both are water-filled HDPE bases for standard 3.5m x 2m temporary fence panels, but they have different profiles and configurations. The Slot Block uses two units of 1750mm each, one at each end of the panel, and stands at 600mm height. The ROTA Slot is a single 3500mm unit that spans the full panel width at 300mm height, with safety bolt fastening. The two-unit Slot Block configuration allows for corner positioning and tight runs. The ROTA Slot at 300mm height has a lower profile and uses one component per panel position. Speak to our team if you need help deciding between the two.

Can I attach debris netting, sheeting or acoustic panels to fence panels supported by the Slot Block Barrier?

Attaching debris netting, sheeting or acoustic panels to fence panels increases wind loading on the fence run and the base. The Slot Block provides 320kg of ballast per set when filled, which is substantially more than standard rubber feet. Whether that is adequate for your specific combination of panel, sheeting type and site wind class needs to be confirmed by your site engineer before ordering. Call us on 0330 056 4420 to discuss your requirements.

Why buy from Securasite rather than a general supplier?

We operate five regional depots across the UK: Wolverhampton (West Midlands), Wigan (North West), Rochester (South East), Brentwood (East), and Livingston (Scotland). Our sales team is available Monday to Friday, 8am to 5:30pm. We hold Constructionline and CHAS Elite accreditations, and white label delivery is available for contractors and hire companies supplying direct to their clients' sites. Call us on 0330 056 4420 or email sales@securasite.co.uk.

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Slot Block Barrier

Price range: £155.00 through £183.50 exc. VAT Price range: £186.00 through £220.20 inc. VAT

Water-filled HDPE base that slots and stabilises standard 3.5m x 2m temporary fence panels on hard-standing surfaces without ground anchoring.

Units per set: 2, one Red and one White
Unit size: 1750mm long x 380mm deep x 600mm high
Assembled height: Approx. 2050mm with fence panel in place
Material: HDPE, 100% recyclable
Rotation: 90° for corners and enclosed layouts
Fence panels: Sold separately, or included in the pair-with-panel variation
Weight:
- 14Kg (Unfilled)
- 160Kg ( Individually Filled)
- 320Kg (Per 3.5m set)
Enhances site safety and visual awareness
Provides extra stability with water ballast

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SKU: SLOT-BLOK

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Product Details

Specification	Detail
Unit length	1750mm
Unit height	600mm
Assembled height (with fence panel)	Approx. 2050mm
Unit depth	380mm
Weight per unit (unfilled)	14kg
Weight per unit (filled)	160kg
Weight per set (both units filled)	320kg
Units required per 3.5m fence panel	2 (one at each end of the panel)
Compatible panel size	Standard 3.5m x 2m temporary fence panels
Rotation	90°
Material	HDPE
Recyclability	100% recyclable
Colours	Red and White (supplied as pair)

Variation	Product Code	Supplied With	Not Included
Red and White pair	SLOT-BLOK-RED-WHT	1 x Red unit (1750mm), 1 x White unit (1750mm)	Fence panels, fence couplers, water supply
Red and White pair with 3.5m fence panel	SLOT-BLOK-WHT-RED-CW-FENCE	1 x Red unit (1750mm), 1 x White unit (1750mm), 1 x 3.5m x 2m fence panel.	Fence couplers for panel-to-panel connections, water supply

Application	Suitable	Why It Fits	Caution or Better Option
Construction sites (tarmac, concrete, paved hard-standing)	Yes	Designed to accept standard 3.5m fence panels without ground anchoring. Units are filled on site from any water source.	Confirm water source availability before ordering. Once filled, the set requires mechanical handling to reposition.
Civil engineering and utility works (hard-standing)	Confirm before use	No ground anchoring needed on paved surfaces. Water filled on site.	Carry out your own site risk assessment. Confirm suitability with your project team before ordering.
Event perimeter fencing on hard-standing	Confirm before use	No ground fixing needed. Water source required on site.	Confirm with your event safety plan and venue requirements before ordering.
Highway and roadwork demarcation near live traffic	Confirm before use	Provides water ballast without ground fixing on highway surfaces.	Traffic management plans and barrier specification for highway use must be confirmed with your traffic management team before ordering.
Soft, uneven or grass ground	Not suitable	The Slot Block requires a firm, level surface to sit correctly and support the panel housing.	For soft or uneven ground, consider rubber fence feet with ballast blocks or the Fence-Lok system where ground anchoring is available.
Fence runs with debris netting or vented sheeting	Confirm before use	The 320kg filled set provides more ballast than standard rubber feet.	Attaching netting or sheeting to panels increases wind loading on the fence run and the base. Confirm adequacy with your site engineer before ordering.
Fence runs with acoustic panels	Confirm before use	Acoustic panels add weight and surface area to the fence run.	Confirm wind load compatibility with your site engineer. Call us on 0330 056 4420 to discuss this application.

Item	Status	Why It Matters	Notes
Standard 3.5m x 2m temporary fence panels	Required (unless pair-with-panel variation ordered)	The Slot Block is designed to accept standard 3.5m x 2m fence panels. A panel is needed at every set position.	Included in SLOT-BLOK-WHT-RED-CW-FENCE. Sold separately with SLOT-BLOK-RED-WHT.
Standard fence couplers (AC-TF-CS-01)	Required	Needed to connect fence panels to each other at every join along the run. Not included in either variation.	Two couplers typically required per panel join. Order alongside your Slot Block sets.
Lockable fence couplers (AC-TF-CPS-01)	Optional	Tamper-resistant panel connections for secure or restricted access sites.	Requires anti-tamper coupler spanners (AC-TF-CSD-02) for removal.
Debris netting or vented sheeting	Caution	Adding netting or sheeting to panels increases wind loading on the fence run and the base.	Confirm ballast adequacy for your wind class and panel configuration with your site engineer before attaching any sheeting or netting.
Reflective strips	Optional.	Increases visibility of the fence line in low-light conditions.	Confirm availability

Product	What It Does Differently	When to Consider It Instead
ROTA Slot	Single 3500mm unit that spans the full panel width at 300mm height. 304kg when filled. Safety bolt fastening. One component per panel position rather than two.	Where a lower-profile base is needed, where a single full-width unit suits the site layout, or where safety bolt fastening is required. Speak to our team if you are unsure which to choose.
Standard rubber fence feet (thermoplastic)	Lightweight single-piece foot. Lower cost per panel position. No water ballast. Separate ballast blocks needed if additional weight is required.	On sheltered sites where basic footing with separate ballast is acceptable. Not where a water-ballasted, higher-load or integrated base is needed.
Fence-Lok system	Ground-penetrating anchored bracket for soil, concrete and tarmac. No water required. Locked and anchored to the surface.	Where ground anchoring is available and a fixed, anchored perimeter is preferred over water ballast.