Required dimensions for Triotherm Door Upstands

In response to frequent inquiries about the available dimensions of Triotherm Door Upstands, we want to provide a clear guidance on dimensions. Our goal is to help you better understand the requirements with ease and clarity.

Here’s an example of how most inquiries about Triotherm Door Upstands typically begin:

"Hi, I am looking for an option for structural insulation to fill my 150 mil cavity under my external doors, ..."

While the phrase "How long is a string?" might seem fitting for this type of question, our commitment is to provide clear and professional responses to every inquiry.

What details do we need foremost?

We require all three dimensions for each of your Triotherm Door Upstands:

1. Total Length

The simplest and most commonly available measurement is the length (sometimes referred to as the "width") of your opening. You can easily locate this information on your floor plan. There´s no need for extending your Triotherm Door Upstand further into the cavity.

2. Total Width

"Total width" refers to the full width (also sometimes called the "depth") of the Triotherm Door Upstand.

Our standard Triotherm+ profile comes in a width of 85mm, making it suitable for most applications. However, if you need a narrower or wider option to accommodate your doors and windows, we've got you covered.

Generally, the door upstand doesn’t need to match the width of the door or window frame it supports. Additionally, it’s important to ensure the upstand doesn’t protrude outward, as this can interfere with the external finish (footpath, drainage channel,...) and create potential issues.

The 85mm Triotherm+ standard width is an ideal fit for door and window frames up to 125mm wide. This ensures a maximum frame protrusion of just 20mm on each side (125mm - 85mm = 40mm ÷ 2 = 20mm), providing both functionality and a clean, streamlined appearance.

Most sliding doors typically require a door upstand wider than 85mm. This can be easily resolved by vertically attaching a strip of our structural insulation board to the 85mm-wide Triotherm+ profile. Alternatively, you can join two Triotherm+ profiles to create a total upstand width of 170mm, providing a straightforward and effective solution.

In situations where your frame width is less than 85mm, allow the Triotherm Door Upstand to extend inward. Thanks to the material's high density, you can confidently install your finishing floor layer directly on top of the upstand, with no worries about long-term tile cracking. 

Alternatively, you can trim the top of the Triotherm Door Upstand to ensure it doesn’t extend inward beyond your door frame. This adjustment is particularly useful for polished concrete floors, as it helps create a clean and seamless transition between the door frame and the finished floor.

3. Total Height

For many clients, this tends to be the most challenging aspect. However, we’re confident it can be resolved with ease.

First of all,  which type of floor layout do you have in place?

A well-prepared floor layout ensures a smoother and more efficient installation of the Triotherm Door Upstand.

Typically, the Triotherm Door Upstand is installed directly onto the subfloor and adjusted to the precise height needed for seamless door or window installation. If your subfloor does not extend into the door opening, you’ll need to fill the cavity up to the subfloor level using either concrete or blocks.

If your floor is already at its finished level, ensure there is a supporting building structure, such as a raft, beneath the floor insulation to provide a stable base for the Triotherm Door Upstand.

You should consult your window and door supplier to determine whether the Triotherm Door Upstand should align with the finished floor level or end slightly below it. Since the upstand height varies depending on the specific window and door manufacturer, we are unable to provide this measurement without details from your chosen supplier.

Here’s a calculation of the Triotherm Door Upstand height by using common parameters:

150mm Floor Insulation  + 75mm Screed/ Concrete  - 30mm below finished floor, as requested by door manufacturer = 195 mm Upstand height