Cast Iron - Features & Benefits

Features & Benefits of Aquaslot

Our standard system offers a comprehensive slot drain solution, complete with options for middle or side slots, decorative covers, and lifting keys. Plus, with our lowest price guarantee, you can enjoy premium quality without breaking the bank.

  • Simple Slide & Lock Covers

    With Aquaslot, maintenance becomes a breeze. Our innovative slide and lock covers ensure effortless removal and replacement, facilitating easy access to the drainage system whenever needed.

  • Decorative & Simple

    Crafted to perfection with the highest quality materials, Aquaslot's slot drain system and covers add a touch of sophistication to any landscape. Designed and manufactured in the UK, they exemplify durability and style.

  • Heel Proof Design

    Safety is paramount, which is why our slot drain patterns and designs are meticulously engineered to provide a heel-proof solution. Walk over with confidence, knowing that Aquaslot prioritizes your well-being.

  • Bespoke Options

    Tailor your drainage system to suit your unique requirements with our bespoke options. From customized cover finishes to lengths and corner sections, Aquaslot offers flexibility and support every step of the way.

  • LED Slot Lighting

    Illuminate your landscape with our LED slot lighting solutions. With dimming drivers ranging from 50W to 320W, waterproof features, and simple installation, enhance both the functionality and ambiance of your outdoor space effortlessly.

Key Considerations

The precise detailing of level thresholds poses significant challenges, often involving adherence to standard specifications indicating a 150 mm difference between the finished floor level and the external ground level. Despite these complexities, level thresholds offer a proactive solution to accommodate the needs of an aging population, promoting inclusivity within architectural designs. Additionally, they serve as a visually appealing element, seamlessly connecting indoor and outdoor spaces.

Furthermore, compliance with level threshold standards is a legal requirement for new residential constructions in the United Kingdom. This mandate applies to all external access points, including front, rear, and side entrances, as well as various door types such as sliding, bifold, French, or terrace doors, ensuring equal access for all. While not universally mandated for renovation projects by building regulations, certain local authorities may request level thresholds as a condition for extensive renovations.

Here, we will examine essential factors to consider during the design of level thresholds to prevent water ingress into the building.

Accessible/Level Threshold

An accessible threshold is characterised by being either level or, if raised, having a total height not exceeding 15 mm, with minimal upstands and slopes, and any upstands exceeding 5 mm must be chamfered.

Building Regulation Requirements

For individual new residential constructions, compliance with Building Regulation Part M4(1) and M4(2) is mandatory. This entails ensuring all access points to the dwelling, including the entrance, garden, and any terraces, are devoid of steps. In the case of larger developments or apartment complexes, local authorities may stipulate that 10% of units comply with Building Regulations Part M4(3), ensuring full adaptability for wheelchair users.

Although compliance with these Building Regulations is not obligatory for extensions, certain Local Authorities, Building Control bodies, and/or Approved Inspectors may impose the requirement to meet Part M4(1) as a condition of planning approval, necessitating accessible entrances and exits for the property.

You can view the latest Approved Document M Building Regulations here.

Ground Floor Thresholds

Designing a level threshold involves considering various factors such as aesthetics, cost, structural integrity, site conditions, and location. Nonetheless, there are several critical aspects that all level thresholds must address.

Door Selection

When selecting a door for use in a level threshold, most manufacturers will indicate compliance with Part M of the Building Regulations. This ensures that the threshold height does not exceed 15 mm and that any upstands are no higher than 5 mm. While sliding door systems typically feature a completely level base frame, careful attention should be paid to the base frame of front and rear doors, particularly those made of timber, which may require specialised aluminum thresholds for full accessibility.

Threshold Drainage

Incorporating drainage into the threshold design is a mandatory building regulation requirement. A drain can be positioned between the sill and external landscaping, either flush with the level floor or concealed beneath finishes. Many door manufacturers offer threshold drains compatible with their door systems, facilitating the efficient drainage of water near the drain and any water that strikes the door or glass and drains through the frame.


Damp proof membranes should be installed to cover the door or window frame system at the threshold point. Proper drainage should be ensured by sloping external finishes away from the drain. Additionally, the damp proof course should extend a minimum of 150 mm above ground level on either side of the threshold to prevent water ingress.