Understanding Bifolding Door Thresholds

When choosing a new bifolding door, one of the most important features of your new doors is the threshold. Additionally, it’s likely you’ll want the very desirable low threshold for the minimal step out to your garden and even having flush floors inside with your decking or slabs outside. In this article, we explain everything you need to know about bifolding door thresholds.

What are bifolding door thresholds?

Look at any external door in your home, and you will see that the threshold fixed to the floor is not just for setting the base of the door frame to your floor, bifolding door thresholds provide weather resistance as well.  

On a bifolding door, this is no different. However, the threshold also has the vital job of holding the carriage and wheels in place.  The carriage at the bottom, with the guides at the top, is what makes our doors effortless slide and fold. It also keeps the door panels safely in place.

What thresholds do bifolding doors come with?

At Aspire, all our bifolding door brands come with a minimum of two threshold opeions. Some offer more depending on the product and intended use. As a minimum you get the following threshold choices:

  • Origin Bifolding Doors with a weathered and non-weathered threshold.
  • Dutemann FD120 and FD85 with a weathered and non-weathered threshold.
  • Schuco bifolding doors come with four possible threshold options.

With Origin and Dutemann bifold doors, the threshold options are quite clear.  The weathered threshold is for external use and carries a weather rating.  The non-weathered threshold is intended for inside use and does not have a weather rating.

We are often asked if the low, non-weathered threshold can be fitted on the outside.  In theory, it can, as we will explain later. However, talk to us and we can give you various options for achieving a level threshold together with a low profile and height.

Schuco doors give you more flexibility as they come with both standard and low thresholds of differing heights.  This is to accommodate many different installation applications including in commercial buildings.

How bifolding door thresholds work

A standard threshold with weather protection has the upstand, seals and gaskets so the base of your bifolds seals tightly against it.  No bifolding door is 100% waterproof. Instead, they are designed and machined with drainage slots for any water that may get in to drain to the outside.  

Never use a jetwash or other devices with water pressure to test your doors.  Not only could this damage the paintwork and the seals, it is not representative at all of the real wet weather conditions, with which your doors are tested.

The weathered threshold is what we recommend. If you want a flush floor up to the threshold we can often recess the standard threshold to give a minimum height of about 12-15mm subject to survey. Your other consideration is which direction the doors open. Opening outwards doors are frequently used for external bifolds and provide great weather protection at the threshold. Inward opening doors do as well, they are simply machined differently.

Giving you a flush bifold threshold and level floors

The desirable ultra-low threshold we make happen for you in several ways. This also depends on whether your new bifolds replace your old patio doors or installed in a new opening.

For an existing opening, we can work with you, removing some of the brickwork under your old doors making your new doors sit lower. Every installation is different and we can explain the process when we survey your property. Normally, the process involves fitting the doors below your floor. As a result, your floor level lines up with the top of the door threshold.

For new openings, step free access is very possible with all our brands, giving you a neat integrated threshold and peace of mind protection during bad weather.

The other benefit of flush bifolding door thresholds is easy access. Perhaps you have an elderly relative in a wheelchair or with mobility problems. Or you have young children and pushchairs. All of these give a barrier-free and minimal trip hazard. In fact, with most doors, the upstand is just 14mm.

You can see our video explaining this process in more detail.

Where can you use a low bifolding door threshold?

There are many reasons to consider a low bifolding door threshold. Some products provide a ramp-type arrangement making it ideal for those with mobility issues that do not want any step over.

You can use a non-weathered low threshold externally but only if your new doors are not subjected to driving rain, perhaps they are under a canopy or in a general sheltered location.  Talk to us and we can advise you further once we have an understanding of your requirements. With several bifolding doors available at Aspire Bifolds, we are confident of finding you a solution.

What are other considerations with bifolding door thresholds?

When we visit your property to discuss your bifolding door requirements, we can also establish whether your door needs a cill.  A cill sits underneath the frame/threshold of your doors and helps deflect rainwater coming down the doors away from the frame.  There are also installations where we work with your builder to provide an acco drain for bifolding doors that works where bifolding doors are flush to the external decking or slabs.

Contact us for more information about bifolding door thresholds.

We can help with drawings, profile samples and more information to help you, your builder or architect design your new extension or property with the ideal thresholds across our entire range of bifolding doors, sliding doors and residential entrance doors.

Our showroom has several full-size bifolding door sets installed where you can see bifolding door thresholds and the relationship between the inside and the outside of your home. Contact us today or just pop in and see us.  We look forward to seeing you and answering your questions.