Campervan Window Installation

Are you wondering how to install a van conversion window? Perhaps you are installing your own or just curious as to how it’s done. In this post we are going to detail the process that we took to install the window on our own conversion. We won’t leave out any of the process and will make sure to explain everything along the way.

Van windows are one of the most commonly outsourced parts of a van conversion process. It is a daunting task and a big one to undertake. However, installing them yourselves can not only save you money, but also improve your confidence in DIY and give you the satisfaction of knowing that you installed them yourselves.

Our van, Faith, had already been through part of the camper conversion process when we bought her, including the base components of a floor, you can read more about that (coming soon!), and also the large camper style window in the sliding door.

We debated for a long while as to whether the single window was enough for us. However, after discussion, we decided that we wanted slightly more light towards the back of the van. This would also create an entry point for circulation when we have the MaxxAir fan pushing air out.

One of the best ways to prevent moisture and dampness in your van is circulating the air within it. Utilising the MaxxAir fan is one way of doing this and having an inlet (the window) and outlet (the fan) will cause the air to be moving constantly, therefore removing the moisture, for example when cooking, boiling water or just breathing in the van. 

This blog and this post represent our experience of building a camper van and installing a small camper window. We have detailed all the steps that we took to install and aim to include all the small details that you won’t find anywhere else (that’s the part that has confused us). If you want to read more about why we are doing this then you can read more about us.

If you want to install a rear camper van window, or install a large front camper van window the steps are very similar if not identical. We have broken down the main sections into a brief summary below and added quick links so that you can skip to a specific question.

Choosing the right window

There are many windows available for a camper van conversion. However, the main two are the large ones that are designed specifically for your van, such as on the side or on the rear or there are small universal windows that are normally fitted at the rear on the side. You can see both these styles of window in the photograph below (taken after this post).

As per Faith’s introduction (here), she already had an OEM looking window installed on the side. As we wanted constant airflow around the van and a little bit more light / air ingress we opted to install the small side window you saw in figure 1. The process for installing a camper van window is very similar across all applications you just need to make sure you cut the right hole and bond it correctly.

We won’t be able to give you a breakdown of installing the large fitted windows at this point in time but you will still get some useful tips on installing a camper van window that will not only help you now but be very useful in future endeavours.

Making a cardboard template

Once your window has arrived it is time to make the bold move and cut a huge hole in your van. If you’re like us and things have been taking slightly longer than expected (a mixture of learning on the go and overconfidence before starting) then we suggest starting this process as soon as you can in the morning to capture all the natural sunlight that you can.

When you are ready the first step is to create a template of the hole that you need to cut. In figure 2, you will see that our window had a step on it and consisted of three different levels. The first being the actual window which would sit flush with the outside of the van, the second being the part that would sit in the hole you would cut and the third being what came into the inside of the van. Therefore, the hole that we needed to template was level 2.

This made templating quite difficult as it wasn’t as simple as placing down the item, tracing and cutting. Instead, the way that we approached this was to create a cardboard cutout for the entire window instead. You will see in the next chapter why this was useful. We then measured the gap between the outside of the window to ‘level 2’ and marked these onto the template.

This allowed us to create a full window template and just a hole sized template.We taped these together to gather the placement for the window.

Deciding on the window placement

After having created the template for the window you are ready to dry fit onto your van. If you are installing a fitted window (i.e. not a universal / any-location window) then your positioning will be fairly strict in where the window can go as it is moulded to your van specifically.

However, for a universal window whilst you have more flexibility in the placement, I would suggest having a rough idea before purchasing. We started this process by placing the actual window on the outside of the van, and then used the template, held it up in different positions and decided from there exactly where we wanted it.

We then determined roughly where this was going to sit on the inside of the van and made some slight adjustments so that the window fitted nicely on the inside too. We taped the template to the van and used a very small metal drill bit to drill to holes (can be seen in figure 4) through the template and through the van side-wall. The idea here is to give ourselves something to align with for the next part of the process. 

Top Tip: Drill your holes slightly off centre and not horizontally level with each other, this will ensure that when you move to the other side you line up the template correctly.

With the two holes drilled we placed the drill bit and another slightly smaller drill bit through them and went back to the outside of the van.

We were then able to place the template onto these drill bits (being careful not to push them out of the holes). It is important to make sure the template is still in the same position as when you drilled, so the side that was touching the van when you drilled through should now not be touching the van.

You can now determine if you are happy with the placement. If you are not make any adjustments to the template to situate it where you wish. If you would like to double check the placement back on the inside you can drill two more small holes (or one if you are feeling brave) to double check back on the inside. 

Top tip: Get some metal aviation snips and cut the supporting beams slightly above / below where you are going to cut. This way you avoid having to cut through two pieces of metal at the same time.

How to level when working with a van 

Now, with the template in the correct position you want to level it to ensure your window isn’t wonky on the van. Traditional, spirit level measurements won’t be useful here as the ground the van is parked on and the object you are working with aren’t going to be parallel. The best method we have found so far is to take something that looks levels with what you are working with, so in this case that is the body panel line that is above the window template in figure 5. 

First of all, we removed the outside part of our template (which represented the whole window) so that we were left with the template for the hole size.

We then used a tape measure to ensure that the left and right hand side were the same distance from the ridge above. Unfortunately, I don’t have any pictures of us doing this.

Drawing and cutting

Apply duct tape or masking tape to the van just underneath where you will draw around the template and the surrounding areas. Then, using the whiteboard pen, draw around the template for the hole onto the side of the van. This will help to guide you around the cutting in the next stage. The reason you want to apply the duct or masking tape is to prevent scratches on the paintwork, we were informed that you could apply the tape to the bottom of the jigsaw and this would do the same thing, it wasn’t until checking in the morning that we saw the paint was scratched everywhere! So we strongly encourage using more tape and applying it to the van and the jigsaw for double protection, but we would recommend to the van at the minimum!

Once you have drawn around the template you can remove that from the van. We then drilled some pilot holes into the template to help us get the jigsaw into the right area. We did this with two stages, the first with a smaller metal drill bit as they are much easier to get through the van walls. Then, with a metal drill bit larger than the jigsaw blade, we went through these holes again. We decided to do one at each corner.

As you can see from the image above, we did a test drill and test cut in the centre of the window cutout to test our straightness and how much force / pressure is needed (not much!). From here you can place the jigsaw into the first hole and begin cutting around the template. 

We tried to keep in the middle of the black marker pen line, which when we did our first dry fitting was perfect. However, we forgot that we would be applying some weather stripping… Therefore, if you are going to be applying weather strip (we recommend!) then go slightly outside of the line / on the outside edge of the line, to account for this. We really struggled to enlarge the hole after cutting it out in the first place.

Top tip: Account for the weatherstrip if you are going to apply some to the window cutout.

Another top tip: When cutting the window out, leave a little bit of metal before the next hole, this will act as a tab that holds the cutout in place whilst you cut the rest of the window. If you don’t do this, you will need lots of tape (you will need some anyway) to hold the window in place, otherwise it really wobbles and will be very difficult.

How do I cut my van using a jigsaw?

Some top tips for using the jigsaw to cut your van. 

Let the blade do all of the work, the metal blades will do a good enough job of slicing through the metal, don’t push to hard otherwise you will snap a lot of blades. 

Take your time on the corners where it rounds, the straight blade won’t want to bend too much or you will be snapping a lot of blades. If you feel a bit of resistance, bring the jigsaw back in the cut path and turn it a little bit sharper in there to essentially start a new straight cut. Alternatively, you could ignore the corners altogether and cut a straight line (to make the window like a hexagon) and come back to the corners at the end.

We managed to go through 5 different blades as we were either pushing to hard, or when it came to a double skin’d wall (for example where the ribs of the inside of the van are) we were pushing too hard to get through. If you remove those before you begin to cut (like we suggest) then this will be less of an issue.

Dry fitting and adjustments

With a large hole cut into the side of the van you are ready to prepare for the window fitting.

First of all you want to dry fit the window to make sure that the hole is large enough. You want to make sure that it fits nicely and will still fit with the weather strip. You could cut some small parts of weather strip out and attach them to the edges to make sure that the window fits. You need to make any minor adjustments that are required to get it to fit properly. We must’ve lifted and test fitted our window over 20 times to make sure that we had the right fit. 

Once you are happy with the fit you will want to use a metal file to unsharpened the edges and apply some rust protect to the edges to ensure they are always protected. Once this is dry, attach the weather strip to the edges of the hole that you have cut and do one final dry fit to make sure that it fits nicely. Ours was a little bit of a squeeze to get in, we had to push it in several places with pressure from both sides to get it to ‘pop’ into place, and although it worked, it would’ve been much easier if it slotted in nice and easy.

Taking the weather strip, begin by pushing the start of it on one of the flat sides of the hole. Continue, pushing down (it might be quite a push to do, so be careful with sharp edges) until you get back to the beginning. You then want to cut the weather strip so that it finishes with a nice flush start to end. We chose to put our break between start and end at the bottom of the window. As we knew it wouldn’t be a perfect join, the likelihood of water ingressing from bottom up was much less likely than from top down.

With the window weather sealant installed and the fitment just right you are ready to install the window. Within the window fitting kit you will get a small bottle of primer fluid, a primer brush (which looks like a fluffy cotton wool bud) and some window weather sealant. You will need to use the primer to apply the primer fluid to the outside edge of the weather sealant where you are going to fit the window. At this point in time it was getting late, and dark, obviously we couldn’t leave a large hole in the side of the van overnight, so advanced apologies for the quality of the upcoming photos.

Top tip: Don’t apply the applicator fluid outside of what where the window will sit, otherwise you will see this black fluid on the outside of the van. We aren’t fully happy with how ours looks and this is definitely something that contributes to that.

You also need to apply primer to the edge of the window too and let that dry. We left ours for 15 minutes or so.

Once it is dry to the touch, you will need to use a skeleton (or drill powered) gun to apply the window sealant that will bond the window to the van. This stuff is thick and strong and requires a large amount of pressure to get out and onto the window. 

The bottle will already be cut so that the adhesive comes out as a triangle, so it is really important that you try to do the whole window in one continuous motion. This ensures that water ingress will be as low as possible (hopefully none!).

Once you are ready and the adhesive is on, place the window into its slot and give it a little wiggle with some pressure to spread out the adhesive. Then use some tape to ensure that the window doesn’t move whilst you let it dry, preferably overnight. The adhesive is super sticky, so the less movement you can make putting it into the van, the better.

It is important that you do not drive the van or slam the doors many times whilst you wait for this to dry as that could un-bond the window and cause some unwanted leaks.

Leak testing

Once the window is dry, you will want to perform a leak test to ensure that you don’t have any unwanted problems in the future. Using a hose, spray the window liberally from the outside and then monitor the inside to see if there are any leaks. We found that we had a small leak on the bottom left hand corner of the window, where water was running from the top, to the bottom and in through a gap in the adhesive. 

We then used a light on the inside of the van to determine where the hole was on the outside. By trying to see the light from angles outside, we found the smallest hole so filled it with some all weather sealant. We let that dry, tried another leak test and it was bone dry, result!

This was a fun project, but we definitely learnt some very valuable lessons for the next time that we do something like this. 

We would first of all use a drill powered skeleton gun (like this) to ensure that our adhesive bead was more consistent and also to save us on the free gym workout that we got trying to squeeze it out. 

We would also account for the weather strip next time as our first cutout was perfect for the window, but the adjustments to make the already cut hole wider (to account for the weather strip) was very difficult and would’ve been much easier having accounted for that.

We would cut the supporting beams for the window before cutting rather than trying to cut both with the jigsaw, and also leave a few metal tabs around the window cutout to avoid having to stick with lots of tape. 

We would also allow for more time, we started our window at 2pm in the afternoon and were still going at 5:30pm when it had gotten really dark, which was not helpful at all!

Finally, we are not overly pleased with how ours looked. We went slightly too wide with the primer fluid and it’s visible from outside the window and we have scratched the paint up on the outside as the jigsaw only tape didn’t work as we had hoped. So make sure to go OTT with tape (better more than less) and don’t go too wide with the primer fluid.

We are going to add some more weather sealant to the outside of the window to cover up the primer fluid and make it look more professional, but we haven’t gotten around to that yet. 

Thanks for taking the time to read through this, we hope that you found it useful and are feeling more confident to install your own camper van window. If you would rather, there are many professionals out there that will take away the stress of installing them yourself and although it’s an extra cost that you might not want to spend, you are paying for their expertise and knowledge in the area. 

We wish you the best of luck!