What is a low aluminium threshold?

You may of heard the term "low threshold" but not know exactly what it is and why exactly you would need one, and if this is the case please read on. This is an option you’ll need to take into account if your in the market for a new front or back door as it relates to the step at the bottom of the door. The threshold itself is the part of the door that separates the outside from the inside, so when entering you would "cross the threshold"

There are many reasons why this is an essential option such as; wheel-chair access, the elderly and those with mobility problems, as well as making it easier for getting a pram in or out and for young toddlers. And of course anyone who would prefer not having a step on the way in, or an extra obstacle to trip over!

For example a standard a upvc, composite, or french door would have a upvc threshold and this would typically be a step of around 70mm. This is simply the bottom piece of a four sided frame, so the frame would be exactly the same on the bottom as it is on the top and sides.

So with a low threshold the bottom piece of frame would be reduced in order to lower the step into your home, tyipically with an aluminium strip, which would be around 12mm in height. This option is available with the majority of external doors including upvc doors and composite doors, as well as aluminium and upvc french and bifold doors. However with sliding patio doors the operation is different, and the options more limited because of the sliding roller mechanism within the frame, however that's not to say a low threshold can't still be achieved.

A low threshold fitted to a composite front door can slightly reduce overall weather and thermal performance. To achieve the reduced step height, the door seals against an aluminium strip using rubber gaskets. While suitable for normal use, this design is not fully weather rated and does not provide the same level of insulation or weather protection as a standard threshold.