There comes a time in every man’s life when he stares out a window and ponders essential life questions. Why don’t I quit my job? Should I break up with my girlfriend? What is that mark on my ass?

Okay, maybe they don’t look at their ass enough to ponfer the last question, but I can guarantee you very few men ponder one of the most important questions staring right back at them: how does a window work?

Have you ever considered what a window is made out of? How was it installed? Could you replace the window if it started leaking?

Ever since I started my shipping container project, I have wondered about windows. And in fact, putting in a window is one of the more complicated parts of building a house.

Window Intersectionality

Women’s Studies majors will be happy to hear that the window has something in common with them: intersectionality.

Builders work hard to create a WRB (Weather Resistant Barrier) that insulates the exterior from the harsh weather outside. A shipping container is notorious for providing a really great resistance to weather; however, that’s only if you like pitch black darkness and have a cold soul.

Most humans (outside of DC) are warm-blooded and need sunlight in their domiciles to function proprely. I am no different, and so I must cut holes in the container to let the sunlight in. I must not fuck with the WRB, though, and so you need to be careful how you put the window in.

Since the web already has a pile of information on how to install new construction windows, I will not add to the pile. Instead, I will focus on the problems I’ve encountered specific to my situation of being new to construction and having to conform advice to use in a shipping container build.

Marking the Cut

The first step in putting in a window on a shipping container is very different from if you were putting a window in a traditional lumber frame. In a traditional frame, the rough opening is already cut and the opening is probably almost level and plumb. In a shipping container, you have no openings so the first step is marking where it will go.

My current bedroom has a window about three feet from the edge of the room and my bed cuts into that making it a bit awkward to put a pillow against the wall and sit up in my bed. Sensing I did not like the bed overlapping the window, I “fixed” this issue by placing the window about five feet from the edge. My bed is five feet wide, so I figured this would allow the bed to not overlap the window at all.

As far as the window’s height, I asked the AI overlords and they told me it would be great to place where a person of average height could see through the window while standing. Since it is a 36x23 inch window, that ended up being four or so feet from where the floor will be built up to.

Now that I had the placement of the window figured out, I had to mark it for cutting somehow and hope that the marks were level enough.

Enter the self-leveling laser level I bought. I ended up purchasing a regular three-foot “torpedo” level and also a self-leveling laser but initially had no use for the laser level.

That is, until I got to marking the lines for cutting the rough openings and figured out I could use magnets on the opposite side of the container to hold the laser level at the proper height. Then, it did all the hard work of leveling for me. As long as I don’t try to level the container any more, I can be assured that the marks are level enough for my purposed.

When I needed to draw the other horizontal and vertical lines, I simply adjusted the magnets holding the laser level and it worked like a charm. Contrast this method with ones that tell you to cut out a cardboard template, and you’ll thank me for not wasting cardboard.

Plus, with a warped and dented container, the template doesn’t work out as well as if everything were straight. However, a laser paints a level and straight line across the whole length of your eventual cut no matter how dented the walls are.

Preparing to Cut the Opening

After marking the cuts, I spent a decent amount of time researching the best way to cut open the container’s walls. Several contenders emerged with three being the most discussed: angle grinder, plasma cutter, and reciprocating saw.

I also discovered and considered trying out sheet metal nibblers or shears. Nibblers punch a hole into the metal leaving little “half-moon” cutouts as the nibbler…nibbles, and shears are basically like heavy duty scissors. Shears are cleaner for making straight cuts but nibblers are better at getting around angles. I’d even say that nibblers are akin to a jigsaw whereas shears are akin to a circular saw when comparing to cutting wood.

However, I could only find examples where people were cutting flat sheet metal and never metal already welded into something like a shipping container. The clearance you need just didn’t seem practical for me to buy a nibbler or shear that I might never use whereas I already had an angle grinder and could see a lot of uses for a reciprocating saw.

The most popular way to cut the container, by far, is the angle grinder, a tool I am still scared of. I am a paranoid man and hearing about angle grinder accidents peaked my paranoia enough to desperately search for another method. After more thought and research, I doubt angle grinder accidents are that much of a concern if you follow directions and wear safety equipment.

One area the angle grinder will always fail on, though, is speed. For this and the general safety paranoia, I chose to go with using an angle grinder to start the cut but finishing it with the recip saw. It is easier to cut a straight line and moves faster than the angle grinder. Plus, if the blade binds you get a bent blade instead of a potentially shattered disc or kickback into your arm or leg.

I have nothing against people using an angle grinder for cutting, but I think grinders were only meant to cut off small pieces like nails. So I try and remember: “grinders are for grinding, saws are for sawing”. Think about what motion makes the most sense in your project and pick the right tool for the job.

Preparing to Attach the Window

As soon as I got my recip saw, I was all hopped up to cut a hole in the container for a window. That is until I realized I did not have a window nor a way to attach the window to the rough opening my cut would create. It was frustrating, but I had to go back to the drawing board and learn about window installations.

Making things worse, most typical construction advice assumes traditional wood framing where you have plywood and house wrap over that. The window buck frame is already there and you simply just need to apply caulk/flashing, nail the window in, and add more caulk and flashing to taste.

My first problem was figuring out how to create depth in the container wall without welding. You need some depth to place the window inside and for screws to hold the frame in place. Without knowing welding, I spent way too much time avoiding learning welding and thinking of intricate ways to still have a window frame that would work.

Every time I thought I solved the puzzle I would start writing down the steps and get to a “how would that work?” question. No matter what I tried, every solution was more over-engineered and with faults than the welding method.

Due to the wavy nature of the wall and its corrugation pattern, using a flat piece of metal welded to the container wall is the best way to create a surface you can attach a frame to. Otherwise, you need some kind of internal or external frame to hold the window’s depth and to nail the window in.

However, that leaves you with vertical and “kind of overhead” welding that I was not prepared for. I ended up opting for angle iron so that I could screw one part into the container’s steel and I could attach the lumber to the other part of the right-angled connector. It seemed to make sense in my head…

Finally Making the Cut

I poured out a fancy beer, took a few sips, and said, “well if this is the day, at least I’ll die with a good taste in my mouth.” Then, I proceeded to turn on my generator, hook up my angle grinder with a cutting disc on it, and start cutting from the inside of the container.

Making the initial starter cuts with the grinder went better than I expected. It is very loud (so you’ll want to remember proper ear plugs in your safety equipment plan) but also very easy to push into the steel and cut away. The sparks take a little while to get used to, but I had a method going in no time for creating my starter holes.

The burning metal smell and potential noxious fumes was the worst. I did put on a mask, but it wasn’t one that filters vapors so I’m not sure if I avoided any medicial risks. You will smell burnt metal after using the grinder, and I even had some paint start smoking on me. So I would be cautious with how long you have the grinder going. I was stopping all the time to let the metal cool down a bit and also to see how far I had to go with the starter cut.

I’d also recommend using a corded grinder as these cuts will eat up your batteries. Transitioning to the recip saw went faster, but I bet I would have went through at least two 5 amp hour batteries just making the starter cuts with the angle grinder.

Once the starters were cut, I switched to my recip saw to finish the cut. I wanted to leave tabs on each side of the cut so that it would be safer to knock out at the end but also since it would be easier to cut.

If I cut around the whole opening without leaving tabs, the container walls would be shaking so badly I would not be able to cut anything. I made that mistake on my first window and it definitely broke the teeth off the saw blade. Even while leaving tabs, the cut was tricky in places and I never had rhyme or reason why cutting some sections were so easy and others hard.

I do know that the recip saw blew away the angle grinder in terms of speed. I could move the saw through the steel in seconds vs. spending minutes just to create the starter holes with the angle grinder.

Bottom line: starting with an angle grinder and finishing with a saw is a great plan. Just make sure to push the saw’s shoe up to the steel or else it will vibrate all over the place and break the blade.

Finally Attaching the Window

After cutting the first window, I was excited to put in the angle iron until I realized the gap was larger than the 2 inch depth of the angle iron. A dent in the wall had crumpled the steel and once cut away, the metal bowed inward more than I expected.

Crap. Double crap…not to mention at exactly this time someone came by to mow the grass where the container is sitting and I felt like the mower was laughing at me the whole time. “You’ll never get your window in this way”, the mower smirked…well, that didn’t happen in real life, but it did happen in my mind.

I had to pause at that point to come up with another plan, and my opening got covered with a garbage bag and duct tape. I felt pretty defeated, but I could envision the solution.

Next day, I went to the hardware store to buy some “Simpson strong ties” that were in a right angle or “L-shape”. The plan was to attach one side of the strong tie to the container steel and the other to the lumber “buck frame”.

Granted, I could have chopped up my angle iron, drilled holes in it, and basically had the same thing as the strong ties, but buying them at the store saved me time. I’m sure I can find a use for the angle iron in the future.

Since nothing in the container is straight, attaching the strong ties also sucked, and I had to creatively screw in the lumber only so many threads in order for the level and plumbness of the frame to remain intact.

The shims got me; meaning I did not have enough space to put shims. The biggest error I made in the whole window install process was not cutting the openings to be the suggested size. I was very close, but in cutting the crooked steel, I inevitable got off the line slightly and the buck frame had to sit a little snugger because of this.

I did use an angle grinder to cut and grind a bit more, but with noxious fumes and sparks, I got tired of the slow process and just made sure the window could fit before screwing the frame fully into place.

Because of the tightness, I also had a bit of trouble placing as many strong tie connections as I should have. I’m confident the windows aren’t going anywhere, but I know a building inspector would have a field day with “what were you thinking?” observations. I did screw the frame together with proper connections, at least, so with a few strong ties, I’d bet the farm it will be okay.

Sealing the Windows

Once the frame was in place and nailed down, I had to finish the flashing. To be honest, I forgot to add flashing tape to the bottom of the second window’s buck frame, but I also used pressure treated lumber so it should be okay.

I followed the standard pattern of doing the sides and then the top, but my biggest flashing failure was not applying enough pressure to the tape. I had seen videos of people using a special roller, but I only applied light pressure on the first window. By the time I got back to it, the tape was peeling up and I had to add duct tape to keep those sections taped down.

I also tried using an “ab roller” device mainly used to roll on the floor and build up your abdominal section, but it was too big to get to the flat surfaces of the tape. So, I mainly used my fingers and nails to really press the tape in. You’ll know when it is fully sealed, but don’t just expect to put up the tape and not have to really press it down. You must do that or else the flashing tape will start peeling.

Window Conclusion

I think I did an okay job of putting the windows in my container. The 2x6 frames matched up nicely and the windows look like other ones I’ve seen when a house is getting built.

I will say that you should:

• use an angle grinder to start cuts
• use a recip saw to finish the cuts
• leave tabs in the steel so the cut is easier with less shearing force
• use a laser level to mark the opening
• mark your cut, then add about half-inch to each side so you really know it will be wide enough
• use more strong tie connectors than I did

If you follow that advice + what’s on the internet already then…well, your window install experience should go a bit smoother than mine.