Installing Split Jamb Doors
Installing split jamb doors can be a bit confusing for the inexperienced. The following instructions are for installing split jamb doors using a package of the Quick Door Hanger installation brackets, available on HomeDepot.com. Using the Quick Door Hanger will take the hard work of shimming out of the installation process, however you will need to remove the casing (trim) from one side of the door before beginning. In the following instructional video, the door has already had the trim/casing removed. We recommend reading the steps below before watching.
About Split Jamb Pre-Hung Doors
Installing a Split Jamb door is different from that of the more traditional flat jamb doors. The difference is that on split jamb doors, the door actually comes from the factory in 2 halves. The halves then sandwich the rough door opening from both sides. Both of these two halves also have the casing (trim) pre-installed by the door manufacturer, flat jamb doors do not. These types of doors are most common in the Southern states, but most types of pre-hung doors are flat jamb. Split jamb doors have been designed for ease of installation for the installer and can work better than a flat jamb door if your wall thickness is not right on. This is because there is a slight overlapping of the two halves when sandwiching the rough opening, giving a little room to accommodate slightly thicker or skinnier wall sizes.
Split Jamb pre-hung Door Installation
Separating the Split Jamb Door
Remove the door from the packaging. Separating the two door halves. Then, working with the half that has the hinges attached to it, carefully remove all the casing (trim) from around the door. Only remove the casing (trim) from this door half. The casing can stay attached to the other half. The casing is usually stapled on by the manufacturer and the easiest way to get the casing/trim off is to use a putty knife or a flat head screw driver.
You will be working with this door half only, until the final installation step.
Attach the Quick Door Hanger Brackets
Attach a bracket behind each of the 3 hinges. Make sure to align the bracket's clearance hole up with the center screw of each hinge. This will allow the addition of a long screw through the hinges and into the wall stud for additional support in a later step. Then attach the remaining 3 brackets on the other side of the door jamb/frame. Place the first 8'' down from the top of the door, the next bracket just above the latch stop, and the final bracket 6'' from the bottom of the door.
Prep the Wall for Door Replacing
A level/plumb line will be needed for the new door replacement. Working on the side of the future hinges, using a 6' or 4' level, carefully draw a perfectly level line down the drywall roughly 1/2'' from the rough door opening. This will be the door alignment aid. Make sure the level is showing perfectly level as we will be basing the split jamb door installation off of this line.
Place the Door into the Rough Opening
Place the door into the opening. Using the plumb line drawn on the wall, screw in the top bracket on the hinge side of the door. Then screw in the next 2 brackets on the hinge side using the same reference notch as the first. After these 3 brackets are screwed into the wall using the same reference notch for each, the door is now perfectly level. Now check the reveal (gap between the door and door jamb) when screwing in the final 3 brackets. Start at the top of the door and check the reveal when screwing in the top bracket. Check the reveal when screwing in the final 2 brackets. The door will now be perfectly hung.
You may want to strengthen the installation if the door is very heavy. Remove 1 of the center hinge screws from each of the 3 hinges and replace with a 2'' or longer screw. The brackets have a clearance hole for the screw to go through if the brackets where placed directly behind the hinges. This new long screw will go through the hinge, through the clearance hole, and into the wall stud. To prevent pulling in the jamb during the placement of these screws, you should place shims or a piece of wood between the door jamb and the wall stud where the screw will go through.
Place the other Door Half
Now working from the other side of the door opening, place the 2nd door half into the opening. As you push the half into the opening, you will notice that it will slide behind the 1st half of the door. Make sure the half is all the way pushed up against the wall. Then, using finishing nails, nail through the door stop on the 1st door and into the 2nd to secure both halves together. Do this about every 18'' to 24''. Finish up this side of the installation by securing the door casing (trim) to the wall by the use of finishing nails. The door casing that was originally removed in step 1 can now be installed back onto the first door half to complete the installation.
Quick and easy – Amazing!
My husband was replacing a 1941 exterior door with a new pre-hung door. In 1941 things were built just a little different so every DIY project is fairly scary! The rough opening was very awkward and without this product it would have taken us hours to shim and level this door. With this product we had the door in the opening is under 20 minutes. We have 2 interior doors to replace and I will be buying 2 more kits. We will NEVER hand a door without these!