When installing a roof lantern, one of the key elements a homeowner, builder or installer will need to consider is the External Timber Upstand (ETU) size. The ETU component plays a crucial role in ensuring a secure, weatherproof, and visually appealing installation. But what is an external timber upstand size, and why does it matter?

Understanding the External Timber Upstand (ETU)

An external timber upstand is a raised timber frame which sits around the opening to support a roof lantern. This provides a stable and supportive base for installation, ensuring proper drainage and insulation in a property.

ETU size refers to the specific external dimensions of the timber upstand. The size is slightly larger than the internal opening to accommodate the frame of the roof lantern. Manufacturers, like those chosen at Lantern Superstore, specify ETU sizes in order to inform homeowners and installers for proper preparation of the roof opening accurately.

Why is the External Timber Upstand Size Important?

Ensures a Perfect Fit

Choosing the right external timber upstand size ensures that each roof lantern sits comfortably and securely on the upstand. Having the correct size also means there will be no gaps or misalignment when installed, as it will be properly sealed.

Improves Weatherproofing

A well-built upstand allows water to drain away effectively, preventing leaks or water ingress into your home. This is due to the secure fitting ensuring their are no gaps around the installed roof lantern or flat roof light.

Enhances Insulation

The upstand contributes to your home’s thermal efficiency, keeping your home warmer in winter, and cooler in summer. If the wrong ETU size is chosen, then this could result in misalignment, creating gaps which may cause draughts, impacting a home’s comfort.

Meets Building Regulations

Builder’s upstands must be typically at least 150mm high to comply with building regulations, helping to protect your home from water pooling on the roof. Regulations may vary depending on your roof type and your local area, so it’s important to check this before installation.

Finding the Right ETU Size for Your Roof Lantern

At Lantern Superstore, we offer the perfect guidance for every purchase.

We provide clear ETU size information for each of our high-quality roof lanterns and roof lights. Before purchasing your roof lantern, you should check the manufacturer’s specifications for the recommended dimensions. Consider the following factors, including:

Roof Construction: Make sure your existing roof structure can accommodate the required upstand height due to it’s weight and materials.

Building Regulations: Before installing your upstand or roof lantern, check compliance with current local building regulations. These types of regulations typically require a minimum height of 150mm for flat roofs.

Weather Conditions: In areas with high precipitation like rain or snow, it may be recommended to build a slightly higher upstand for better protection against the elements.

Lantern Size: It’s crucial to match the external dimensions of your upstand with the roof lantern’s recommended ETU size, as this allows for a seamless installation.

Brett Martin Roof Lanterns

For our Brett Martin Roof Lanterns, the external upstand requirements are as follows:

Roof covering must cover side and top of insulated upstand in accordance with manufacturer’s installation recommendations. There should be no excessive build up of layers, and the top surface should be level and free from protrusions or projections which may prevent adequate weatherproofing.

Roof Lanterns are intended for installation onto a fully weathered and insulated builder’s upstand on flat and low pitch roofs. The surface of flat roofs normally require some degree of pitch to ensure adequate water runoff. For aesthetic reasons we recommend that the upstand is built with 0° pitch i.e. not parallel with the pitched roof surface. The rooflight can accommodate being installed on an upstand with a pitch of up to 5° but please note that this will likely result in a ‘lopsided’ appearance

Sovu Roof Lanterns

Our Sovu roof lanterns have the following requirements.

Once you have built your timber upstand, it is critical that the opening matches the size of the lantern.

Ensure there is a 4×3 upstand and check this is square and level.

Stratus Roof Lanterns

Stratus Roof Lanterns are recommended with a timber upstand at 150mm high, and 100mm wide, with a weatherproof membrane. This provides effective support and height for water run off. The roof lanterns achieve a standard roof pitch of 20 degrees, similarly creating effective water run off to avoid water pooling. Fitted with the right external timber upstand size, these lanterns are a great solution to let in plenty of light, and provide excellent thermal comfort.

Roof Lanterns: External Timber Upstand Sizes

The External Timber Upstand is a vital component in the installation of a roof lantern or rooflight, ensuring durability, weather resistance and thermal efficiency. However, it’s just as important to invest in a high-quality roof lantern.

At Lantern Superstore, we provide expert guidance and information to help you choose the right roof lantern for your project, ensuring a perfect fit for your home. Whether you need something minimalist and small, or larger roof lanterns, we have a variety of design options to suit your needs with all our roof lanterns. Plus, with our versatile stock sizing options and made-to-measure options, you can find the perfect size to suit your unique needs. We even have advanced glazing options such as self cleaning glass units, alongside double glazed units as standard.

Looking for the ideal roof lantern installation? Browse our extensive collection today and elevate your home with style and natural light!