MARDOME TRADE FIXED - RELIABLE DAYLIGHTING
The Mardome Trade Fixed Polycarbonate Rooflight is designed to provide reliable, cost-effective daylighting for flat and low-pitched roofs. Featuring a robust polycarbonate dome, it delivers excellent impact resistance, long-term UV stability, and simple installation — making it a popular choice for residential, commercial, and industrial applications.
KEY FEATURES OF MARDOME TRADE
Robust Construction
Manufactured from tough, impact-resistant polycarbonate for long-term durability.
Flexible Glazing
Available with single, double, or triple skin glazing to meet thermal efficiency needs.
UV Stabilised
Glazing is UV-stabilised to prevent yellowing and maintain clarity over time.
Versatile Mounting
Designed for simple mounting directly to a builder’s upstand or supplied with a kerb.
KEY BENEFITS OF MARDOME TRADE
Maximum Daylight
Fixed, non-opening design ensures maximum natural light transmission with a weathertight seal.
Cost Effective
Balances high performance and affordability without compromising on strength or quality.
Easy Installation
Lightweight construction makes for easy handling and rapid on-site installation.
UK Manufactured
Manufactured in the UK for dependable quality and reliable availability.
VENTILATION AND OPENING OPTIONS
Ventilation can help reduce humidity and the risk of condensation and should be considered in any areas of high humidity. Brett Martin Flat Glass roof lights may be unvented or can incorporate vents. These can be hit-and-miss, manually controlled trickle vents and are available in all sizes where a PVC kerb is an option.
How the "Automatic" Mechanism Works
The "Automatic" version uses a hygroscopic sensor. This is usually a bundle of specialized nylon or fabric strands that are extremely sensitive to moisture in the air.
At High Humidity: When the air inside your room gets humid (e.g., from cooking, showering, or even breathing), the hygroscopic fibers absorb a tiny amount of moisture and expand (stretch). This physical expansion creates enough mechanical force to push a lever or pull a shutter open.
At Low Humidity: As the air dries out, the fibers contract (shrink), which pulls the vent back to a closed or "trickle" position.
The "Hit & Miss" Part: This refers to the physical design of the vent. It consists of two slotted plates. When the slots align, air flows through (the "hit"); when they are offset, the air is blocked (the "miss"). In the auto version, the humidity sensor does the sliding for you.

Why choose one over the other?
The Manual Version is better if you are sensitive to drafts and want the vent closed even if it's humid (for example, if you're using a separate dehumidifier).
The Auto Version is a "set and forget" solution. It is particularly great for meeting Building Regulations (Part F) because it ensures the room is ventilated exactly when it needs it most (to prevent mold) without wasting heat when the air is already dry.
Mardome Trade Fixed Polycarbonate Rooflight
The Mardome Trade Fixed Polycarbonate Rooflight offers a straightforward, reliable solution for bringing daylight into flat-roof buildings. Built from high-quality, UV-stabilised polycarbonate, it balances performance and affordability without compromising on strength, thermal efficiency, or design flexibility.
Ideal for a wide range of sectors, the Mardome Trade Fixed Rooflight combines ease of installation, low maintenance, and proven durability. Whether you are working on a new-build, refurbishment, or replacement project, this unit is built to deliver lasting value.
Product Overview
This fixed (non-opening) rooflight allows maximum natural light into the building while maintaining a weathertight seal, ideal for spaces where ventilation is not required. The Mardome Trade Fixed Rooflight is available in a wide range of sizes, with options for glazing skins and tints to meet your project’s specific performance and aesthetic needs.
Key Features & Benefits
Fixed Design: Non-opening design for maximum daylight with weathertight protection.
Impact Resistant: Manufactured from tough polycarbonate for superior durability.
UV Stability: UV-stabilised glazing prevents yellowing and maintains clarity.
Glazing Choice: Available with single, double, or triple skin glazing.
Tint Options: Choice of clear, opal (diffused), or patterned tints.
Versatile Fit: Suitable for installation onto an existing builder’s upstand or supplied with an insulated kerb.
Compliance: Fully compliant with relevant UK building regulations for daylighting.
Explore Our Full Range
PDF Resources
Technical Specifications
Customise your rooflight to match your property’s thermal and aesthetic requirements.
Installation & Pitch
Roof Pitch: Suitable for flat roofs and low-pitched roofs up to 15°.
Mounting: Direct to builder's upstand or with Brett Martin insulated kerb.
Glazing & Tint Options
Choose the right combination of skins and tint for your privacy and thermal needs.
| Glazing Skin | Available Tints |
| Single Skin | Clear, Opal, Patterned |
| Double Skin | Clear, Opal, Patterned |
| Triple Skin | Clear, Opal, Patterned |
PDF Resources
The Mardome Trade Fixed Polycarbonate Rooflight is designed for quick and secure installation onto flat or low-pitch roofs.
It can be mounted directly to a builder’s upstand or supplied complete with an insulated kerb, offering flexibility for different project requirements.
Installation guidelines
- Suitable for installation onto existing builder’s upstands or with a supplied Brett Martin insulated kerb.
- Ensure the upstand is correctly dimensioned, insulated, and weathered prior to installation.
- Glazing must be correctly orientated, with the UV-resistant layer facing upwards (as marked).
- When using the direct-fix (sloping) method, refer to the installation guide for appropriate fixings and sealing procedures.
- Thermal fracture caution: Avoid placing blinds directly beneath the glazing; use light-coloured blinds positioned away from the rooflight to reduce risk of thermal stress fracture.
- Minimum upstand height and slope should be checked per building regulations and installation guide recommendations.
*Brett Martin Daylight Systems operates a policy of continuous product improvement and reserves the right to alter specifications at any time without notice. Every effort has been taken to ensure all details contained in this video are correct at the time of release but this video should be used only as a guide and does not in any way form part of a contract or warranty. It is the customer’s responsibility to ensure that the product is suitable for the actual conditions of use, which are beyond the control of Brett Martin Daylight Systems.
How your mardome rooflight Is Delivered
- Delivered kerbside by the Brett Martin transport fleet
- Glass and frame delivered together on an A-frame
- Driver can assist with unloading if required
- Sacrificial foam runners protect the glass during unloading
- The A-frame is removed by the driver after delivery
Important: Please ensure someone is present on the day of delivery to help unload the rooflight from the lorry.
Delivery Times
Standard Trade Fixed rooflights delivered within 1–2 working days. Free UK mainland delivery.
Orders placed before 12 noon (Monday to Friday) are prioritised for dispatch.
Delivery Cost
Delivery is free to all UK mainland addresses.
Excluded Postcodes
We currently do not deliver to the following areas without prior arrangement:
Scotland, Northern Ireland, Channel Islands & Remote Areas
HS, IM, IV, ZE, BT, KA27–28, KWA, PA20–49, PH17–50, PO30–40, TR21–25, LL58–78
Contact our team to check if delivery to your area can be arranged.















