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Writer's pictureMR Post Frame

Modifying a Garage Door Opening

Updated: Dec 19, 2023

Part 1 | Removing Metal and Adding a Footing for Widened Garage Door


In the less-than-ideal scenario where you needed to widen a doorway, we are here to assist. We constructed a 50 by 120 building last spring, and then the client decided they wanted a wider door. This isn't the most convenient situation, it would have been easier to create a wider door during the initial construction. Nevertheless, I agreed to widen it for the client.

marking new column placement

Before proceeding, I needed to add another footing, but I had to carefully plan how to do this without affecting the trusses or the building's structural integrity. The original door was 10 feet wide and 12 feet tall, and the goal was to make it two feet wider. There was a header in place with one of our trusses resting on it. I wanted to avoid altering that side, so I decided to work on the other side.


To begin, I needed to remove the exterior metal and determine the precise locations for my piers to support the new column. I wanted to install the new column before removing the old one to ensure that the roof remained adequately supported. I started by taking off the trim on the door's side and removing the metal to access the area needed for drilling the footing.


Removing metal cladding

I removed the necessary sections, allowing me to bring in my skid steer and drilling equipment. While it was possible to hand dig the holes, it wasn't the easiest option, so I found it worthwhile to use my machine. My objective was to position another post exactly two feet away from the original one. I measured from the outer edge of the post, marked the spot, and then proceeded to drill the hole. After that, I mixed concrete with my concrete mixer for the new pier, poured it, and let it set. For this particular footing, we used 5000 psi concrete. Usually, I use 4000 psi, but I opted for bagged concrete as it wasn't cost-effective to have a concrete truck come out for just one footing.


I had already ordered the necessary metal and new trims, so I had to give the concrete a few days to set.


Part 2| Installing New Column and Header and Removing the Old

This is the process of installing a new column, removing the metal cladding, fitting new headers, and completing the project. We got started with widening this garage door by installing a new column. I used my tape measure to hook onto the column that was already there and then marked the necessary points. I marked two feet from that column because that was where I wanted my door widened to. Then I used my lift and secured the new column temporarily using temporary bracing.


a tool used for securing building materials with nails and screws

Next, I nailed and screwed it securely in place with my Bostitch jumbo nailer. I usually use the Fasco nailer, but I decided to order the Bostitch brt 130 jumbo nailer because I needed another one and the Bostitch one was much more affordable and wasn't on back order. It shot the same nails and worked just as effectively.


I then needed to attach the new column to the existing girts. With the new column in place, we needed to distribute the weight of the truss properly. I used a 16-foot board from the left column to the new one on the right. This served as a header, providing the needed support. A similar header was installed on the other side, ensuring the roof was now supported by the new column.


Now, let's tackle the tricky part—attaching the new and removing the old. We used screws and nails for stability and support. I then removed the old header. I used my hammer and crowbar to remove each individual nail. Safety glasses were essential during this process to avoid any mishaps. My HySpec safety glasses saved me when my hammer flew back toward my face. I could have really damaged my eye but my safety glasses were there as a barrier.

Attaching headers

After successfully removing the old header, I needed to work on securing the new one. I measured and cut the new header, loaded it onto my lift, brought it up there, and nailed it in. I also had to add supports to the new column. We then trimmed it out and prepared for the next steps.


We completed the door widening process and removed the old column. Everything was now framed back in. To avoid complications with the existing trusses, we left the original headers in place and added new headers below them for additional support. This ensured the roof structure remained intact.

The final result is a 12 by 12 garage door

In conclusion, we successfully widened the garage door to a 12 by 12 size, meeting our client's requirements. This project took about two days of work. A valuable lesson here is to consider the size of the largest items you plan to store when designing your building to avoid complications later on.


This demonstrated that you could expand a door without compromising the roof structure. We were pleased with how it turned out. Now, it's time to tidy up, reinstall the metal cladding, and complete the project. We first just added some house wrap back on. We then measured, cut, and installed the metal.


Thank you for joining us on this garage door widening project. It's now a 12 by 12 door, precisely what our client wanted. In closing, remember to plan for your building's needs from the start, and avoid having to make major changes later on. It's always more challenging to revise something after it's done. We hope this has shown that you can modify your door without affecting the roof structure.


Thank you,

MR Post Frame



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