Manufacturers, Suppliers and Installers of High Quality
Aluminium and UPVC Windows, UPVC Doors,
Composite Doors, Folding Doors, Double Glazing
and Conservatories since 1988

Aluminium Folding Doors Threshold Details

Our aluminium folding doors come with two different threshold options which are suitable for different applications. An ultra low threshold that is only 15mm high, and a standard threshold that provides improved weather peformance.

Our surveyor will be able to advise you on which option is most suitable for your application, however if you are purchasing aluminium folding doors as supply only, or you are currently building the opening the following information will be relevant to you.

When choosing a threshold for your aluminium folding door you need to consider:

• Weather peformance and exposure to wind and rain
• Internal floor height compared with external floor level
• Required stepover height (ie height of threshold above internal floor level)
• Door opening direction (open out vs open in)

The standard threshold provides improved weather performance over the ultra low threshold, however unless the folding doors are highly exposed to wind and rain then both options will be more than adequate for most situations. If your folding doors are highly exposed to wind and rain then the standard threshold would be more suited to that situation.

Both thresholds can be used with or without a cill. The ultra low threshold without a cill is suitable for situations where the internal floor level is similiar to the external floor level i.e. where you want to provide a seamless transition between the inside and outside.

However, in most situations the internal floor level is higher than the external floor level, so either the ultra low threshold or standard threshold sitting on top of a cill would be suitable. In approx 80% of all installations a standard threshold is chosen, as it provides better weather perforance and providing a proper survey is carried out the height of the threshold above the floor can be minimised accordinlgy.

The different threshold options are shown below.

Ultra Low Threshold with cill

The ultra low threshold is 15mm high on top of a 25mm cill (making 40mm in total). The detail is the same whether the doors open inwards or outwards (apart from the sash profile being reversed). If the doors are open in then remember to leave enough height for a floormat if you plan to have one, or for uneven floor surfaces.

The internal floor level can be built upto the top of the threshold if desired, however it is normal for the threshold to sit 10-20mm above the internal floor level.