Thresholds

Blog #5 – Thresholds

Attention to every detail is key when building an accessible home. A few years ago, I participated in the construction of an accessible home for a family with two young men in wheelchairs.  I was not involved in the design, because I came to the project late, but I was actively involved in the actual construction.  Although my intention was to give back to the community, I actually received more (in the form of knowledge) than I gave.  One of the small but critical aspects of accessible design is the threshold at exterior doors.

Thresholds in all commercial applications are required by law to be not more than ½” high and all commercial doors are designed to meet this standard; however, residential doors have no similar requirement.  A large supply company had been approached to participate in the project and offered to supply windows and doors below cost.  I ordered the double doors for the front entrance and installed them early on so that we could secure the house.  Shortly after installation, one of the young men came to the home and found it nearly impossible to enter through the front door, because the threshold was too high – it was a standard height threshold and was high enough to flip the wheelchair.  Clearly this needed to be corrected.

I did some research and found that adaptor kits were available.  The kit consisted of an ADA compliant threshold (1/2” high) and a U-shaped piece that fit on the bottom of the door and would adjust to close the gap created by lowering the threshold.  This is a simple and easily installed modification to existing exterior doors; however, there was another issue.  These were DOUBLE doors, which have an astragal – the piece that slides into the threshold and keeps the stationary door stationary.  Unfortunately, there was no adaptor for the astragal and when the threshold was lowered, the astragal was too short.  The simplest solution was to remove the double doors and replace the existing door jamb with a unit that included an accessible threshold.  The double doors were reinstalled and the new threshold works fine.

I contacted the company that was supplying the remaining exterior doors and requested that they be delivered with ADA compliant thresholds, which look exactly like standard units, but with a lower profile.  Installation was uneventful and the wheelchairs rolled smoothly over the thresholds.

I learned two things from this experience: a) you must specify ADA compliant thresholds when ordering exterior doors for an accessible home, because, even if the door company knows they are available, it may not be intuitive to include them, and b) if you are remodeling or otherwise working with standard thresholds, adaptor kits are available, except for double doors.