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Made in UK

Thermal Performance

Building Regulation Compliance

Easy Fit


Mardome Trade Polycarbonate Roof Dome Window

Introducing the Mardome Trade Polycarbonate Roof Dome Window by Brett Martin – the cutting-edge solution for a stylish and secure skylight. This multifunctional, low-rise domed rooflight is designed for maximum aerodynamic performance and offers an extensive range of sizes and options to suit any flat roof.

Choose between dome or pyramid shape designs, with a selection of finishes and glazing variations available. Mardome Trade products are manufactured in the UK to the highest specification by Brett Martin. Ensure your home has a strong, durable roof light that looks great while providing natural light into living spaces below.

The Mardome Trade Polycarbonate Roof Dome Window goes beyond aesthetics; this highly functional product also provides excellent energy efficiency and weather resistance. It’s quick to install with no need for additional support, making Mardome Trade the perfect choice for polycarbonate rooflights flat roofs.

Providing a sleek, secure solution that looks great in any home, Mardome Trade Polycarbonate Roof Dome Window is the ideal way to bring natural light into your living space. Discover the Mardome Trade range today – make sure you get the best from your rooflight!

Fitting and Measurements

The product data sheet and instructions for installation in PDF form to download can be found at the foot of this page.

Please read the following installation instructions first.

Available Sizes

We offer a broad selection of sizes from 450x450mm to 2400x1800mm in 150mm increments as standard. However, we can also accommodate bespoke dimensions; please get in touch with the sizes you need and we’ll be happy to provide expert guidance and talk about your options.

Builders Upstand Installation: How to Measure

Please refer to the diagram below for a guide on how to measure the dimensions of the external builders upstand.

Acceptable margin:

Fixed / unvented domes = dome size +20/-20mm

Opening / vented domes = dome size +40/-20mm

The height of the builders upstand should be 150mm and the wide 75mm, as seen in red on the diagram above. This means that the item you are purchasing from our menu should match the dimensions of your external timber. For example, the purchased item should be 900x900mm and your external timber should measure 900x900mm. The external timber size can be seen on the diagram above in red marked “measure here”.

Domes With PVC Kerb: How to Measure

Please refer to the diagram below to see how to measure the internal opening of the roof.

Acceptable margin:

Dome size +20/-30mm

You can pick the dimensions you need for your timber size from our order menu. The timber size (which is the red measurement on the above diagram) is the same as your structural opening size and when buying with a 150mm/300mm upstand should match.

For example, if you purchase 900 x 900mm, your structural opening dimensions should also be 900 x 900m.

Fitting Video Guide

Fitting Video Guide

Fitting Video Guide


Glazing Details:

Glazing type thermal efficiency: refer to Centre Pane U-Value
Entire rooflight thermal efficiency: refer to Ud-Value

Note: depending on the dimensions selected, glass glazing may limit the choice of openings and cannot be offered with an access hatch.

In order to comply with Part L Building Regulations, a minimum U-value of 2.2w/m2K is required. In addition, triple skin rooflights (minimum) are recommended by the manufacturer in every installation.


The light transmission qualities of the Reflex polycarbonate rooflight are displayed in the table below:

The qualities each type of tint offers is as follows:

Clear: High Visibility

  • Optimal light transmission
  • Improved visibility throughout the dome
  • Enhanced transparency

Opal: Solar Reduction and Diffused Light

  • Combines maximum generation of diffused light with privacy
  • Reduces solar heat gain and blocks solar glare
  • Minimises visibility through dome

Patterned: Enhanced Privacy

  • Enhances transmission of light while protecting privacy
  • Minimises visibility through dome

Bronze: Solar Reduction

  • Minimises heat gain and solar glare
  • Delivers lower light transmission


Opening/Vented Builders Upstand

A uPVC frame is provided with this dome which attaches onto the top of all the opening equipment, ventilation and builders upstand.

150mm uPVC

Delivers 150mm waterproofing and insulation and can be mounted at the level of the roof surface.

Note: the specification will determine the final kerb profile.

300mm uPVC

Delivers 300mm waterproofing and insulation and is usually mounted below the level of the roof surface.

Trickle Vents

8400mm² equivalent area ventilation is provided via two hit and miss trickle vents (manually operated).

Note: 450mm x 450mm cannot be fitted with trickle vents.

A 10-year warranty is included.


Production for this item is usually 2-3 days provided it is ordered in one of the sizes listed below:

  • 450 × 450
  • 600 x 600
  • 750 × 750
  • 900 × 600
  • 900 × 750
  • 900 × 900
  • 1050 × 600
  • 1050 × 750
  • 1050 × 1050
  • 1200 × 600
  • 1200 × 900
  • 1200 × 1200
  • 1350 × 1050
  • 1350 × 1350
  • 1500 × 1050
  • 1500 × 1500
  • 1800 × 900
  • 1800 × 1200
  • 1800 × 1800

If the item is ordered in a pyramid shape, the production time will be extended to 3-7 working days.

Any sizes other than those listed above will be subject to capacity, but typically also 3-7 working days.

Any equipment or installation arrangements should be made once the item has been successfully delivered.


TB200 Datasheet Mardome Trade
TB186 Installation Mardome Trade