Door Undercut

The simplest pathway is a door undercut but often it needs to be pretty high 1 1 2 in or greater in order to allow enough air to pass.

Door undercut. There are after market devices available that you can install on the door to fill that gap but you must be very careful as you can only install devices that have been listed by an independent testing laboratory i e. Wide strip of masking tape along the line to protect the door s finish from the circular saw s base plate. So if you can get 60 cfm under the door you can get about 120 cfm total. For example to undercut a door would mean to cut the door to allow it to swing properly as well as clear any carpet or other flooring that is installed under the door.

The following details represent the recommendation of the steel door institute in this important corollary area. Then pull out the hinge pins and lay the door on padded sawhorses. The distance between the bottom of door and the bottom of the frame. Semmelhack believes the air flow through the sides and top of the door is equal to the air flow through the undercut.

I figured the in. 7 doors provided with 3 4 undercut unless otherwise specified. Any clearance under the bottom of the door while it is in the closed position that exceeds inch will be considered non compliant. As of the writing of this article ngp s gap solutions are the only.

111 e recommended guidelines for the use of gasketing and thresholds for standard steel doors and frames. Other alternative pathways are jump ducts and transfer grills. The distance between the bottom of the door and the top of the material directly below the door. A solution for fire door gaps.

Ul fm approval intertek that have been approved for that purpose. Seasonal changes in wood can result in variations in the height of the door undercut opening. To be sure i did some testing. Undercuts on the doors to the three bedrooms in one of my rental houses were inadequate.

The door undercut gets all the attention but the sides and top of the door also allow a good amount of air to flow through. A cost and time effective solution for excessive fire door gaps. Mark the cutting line on the top face and edges of the door and apply a 6 in. First mark the clearance needed on the door.