An overview of hollow metal frames for commercial doors

Ordering hollow metal doors & frames can seem like a complicated task but once you get an understanding of how steel door systems work you’ll probably find it to be relatively easy to order and install this type of material.
Here are some points that you may need to verify before ordering commercial doors with hollow metal frames:
Rough Opening:Measure the width and height of the opening in the wall where the entire door and frame assembly will be installed?
Finished Wall Thickness: What is the total thickness of the finished wall?
New Wall Anchors or Existing Wall Anchors: Are you installing this door in a wall that has already been built or will you be installing the door frame while you are constructing the wall?
Wall Type: What type of wall is this?

  • Drywall + Wood Stud
  • Drywall + Metal Stud
  • Masonry (Block Wall, Poured Concrete / CMU
  • Metal Building
  • Other

Fire Rating: Does this opening require a fire rating? Typical fire ratings for doors are 20, 45, 60, 90 & 180 minute.

Door Handing:

  • (LH) Left Hand: When viewed from outside hinges are on the left and door pushes in.
  • (RH) Right Hand: When viewed from outside hinges are on the right and door pushes in.
  • (LHR) Left Hand Reverse: When viewed from outside hinges are on the left and door pulls out.
  • (RHR) Right Hand Reverse: When viewed from outside hinges are on the right and door pulls out.
Sidelites and Transoms:Does this frame have any sidelites or a transom? A sidelite is a glass panel at the side of the door opening. A transom can be glass or a panel that is above the door opening?

Knocked down metal frames & welded frames:Knocked down metal door frames are packaged in 3 piece sets. Welded frames are provided as a 1 piece frame.

Hollow Metal Frames Explained
Most hollow metal frames are sold with custom factory modifications that include custom hardware prep, additional reinforcements and several different wall anchors for fast and easy installation in almost any wall type. Understanding the different types of steel door frames and selecting an anchor that is both suitable for your wall type and will fit your rough opening is critical to the function of the door and its ability to be installed.

When ordering hollow metal doors and frames be sure to measure properly and choose a door and frame that will fit your rough opening and be able to anchor to your wall. Make sure you confirm the fire rating and door handing before you proceed with ordering material.

Frames for Existing Drywall Applications
Hollow metal drywall frames are also called 3 piece knockdown frames, K.D. Frames or even slip on drywall frames. These door frames are intended to wrap around a finished wall. Hollow Metal Drywall Frames require a rough openings that is about 2” wider and 1” taller than the nominal door size. When consideringa knock down drywall frame it is important to point out the difference between the overall frame depth and the throat size. The throat size should be equal to the wall thickness. Because it wraps the wall and extrudes outward by ½” on each side, the overall depth of a hollow metal drywall frame is usually one inch greater than the throat size. The most common sized hollow metal drywall frame depth is 5-7/8.” A 5-7/8” Hollow metal drywall frame has a throat size of 4-7/8” and perfectly fits a standard steel stud wall that used a 3-5/8” steel stud and 5/8” drywall on both sides.

Tip: Make sure you are not confusing the overall frame depth with the throat size. The throat size should be the same as your wall thickness and the overall size should be one inch greater. Drywall frames are usually referenced by the overall frame depth and not the throat size so be sure to review your order carefully and make sure the throat size is equal to your wall thickness.

Butt Type “Flush Mount” Frames for Existing Walls
Existing block or poured walls usually require what is known as punch & dimple, or existing masonry wall anchor. A punch and dimple anchor for existing masonry walls allow the door frame to be bolted to the wall with a masonry expansion bolt or sleeve anchor. Most existing wall anchors include a pipe and strap reinforcement or a butterfly reinforcement to prevent the frame from being damaged from the tightening of the bolts. Optional lag screws can be used to anchor the frame to a wood stud wall in the same manner. Because this frame does not wrap a wall and butts up inside of the opening you must account for the full frame face dimensions when calculating the rough opening. Typical commercial steel door frames have a 2” face profile at the head and both sides. The outside unit dimensions of a door frame with this anchor type is typically the nominal door width plus 2” and nominal door height plus 2”.

Tip: Allow an extra ¼” to both the width and height the outside frame dimensions. This will make it easier to install and square the frame.

Frames for New Masonry Walls
Masonry type frames are usually installed in exterior block or poured concrete walls. Almost all masonry type frames require rough openings that are 4” wider and 2” taller than the called door size. These frames are meant to be installed at the time the wall is being built. Wire anchors fit inside the frame throat and are placed between the layers of block as the wall is being built. Wire anchors can also be used in poured walls. In a poured concrete walla wire anchor is placed around a section of rebar and fits inside of the frame throat. When the wall is poured the door frames become filled with concrete.

Tip: Order your door frames in advance. You should have your frames on-site before beginning construction of the wall.

Frames for New Stud Walls
In this application the installer will fasten the door frame directly to the wall stud and then tuck the drywall underneath the door frame to give it the same look as the slip on drywall frame. In most cases these anchors are ordered with welded frames being installed into newly framed walls. The door frames must be anchored directly to the walls studs before the drywall is installed. Typically these frames require a rough opening that is 4” greater than the nominal door width and 2” greater than the nominal door height.

Tip: Order your frames in advance. You should have your frames on-site before you start framing the wall.

Commercial steel door frames are designed to be durable, easy to install and to meet a wide range of commercial building codes. If the correct products are selected and the proper methods of installation are followed these frames are often easy to install.