Required Dimensions for Triotherm Door Upstands

In response to frequent questions about the dimensions required for Triotherm door upstands, we have put together the following guidance.

The correct upstand dimensions depend on the individual floor build-up, door or window frame depth, threshold position and the required connection to the building’s insulation layer.

The aim is to determine the required height, width and length of the upstand before ordering or installation.

What Information Is Required?

To determine the correct dimensions, the following information is normally required:

• door or window opening width
• door or window frame depth
• finished floor level
• floor build-up
• thickness of floor insulation
• screed or concrete thickness
• threshold position
• wall construction
• position of the insulation layer

With these dimensions, the required Triotherm door upstand can be configured to suit the individual construction detail.

Determining the Upstand Length

The required length is generally based on the structural opening width or the overall width of the door or window element.

Triotherm+ profiles are supplied in standard lengths of 1,175 mm and can be connected using the integrated dovetail connection to create longer upstands.

The final length should be coordinated with the actual door or window dimensions and the required installation tolerances.

Determining the Upstand Width

The width of the upstand should suit the depth of the door or window frame and the required load-bearing area beneath the threshold.

The standard Triotherm+ profile is 85 mm wide and can be combined with Triotherm Structural Insulation Board or MultiPro Structural Insulation Board where a wider upstand is required.

This is particularly relevant for:

• deeper door frames
• sliding-door thresholds
• lift-and-slide systems
• floor-to-ceiling glazing
• bespoke threshold details

There is normally no need for the Triotherm upstand to extend beyond the door or window frame unless this is required by the specific construction detail.

Determining the Upstand Height

The required height is normally determined by the floor build-up and the intended position of the door threshold.

As an example:

150 mm floor insulation + 75 mm screed/concrete − 30 mm = 195 mm required upstand height

This is only an example. The actual height must always be based on the specific floor and threshold detail.

The aim is to position the door or window frame correctly in relation to the finished floor level while maintaining continuity with the insulation layer

Consider the Finished External Level

The external build-up should also be considered when determining the final upstand dimensions.

This may include:

• external paving
• footpaths
• drainage channels
• terraces
• external insulation
• waterproofing details

The objective is to ensure that the threshold, waterproofing and external finished levels can all be integrated correctly.

Consider the Internal Floor Finish

The internal floor finish should also be included in the dimensional planning.

Depending on the project, this may include:

• tiles
• timber flooring
• engineered flooring
• vinyl
• other floor finishes

The final threshold position should allow the internal floor finish to connect cleanly to the door or window frame without creating unsupported edges or unnecessary level differences.