How to measure an RV skylight

When it comes to boosting comfort in an RV, one of the main things to do is get a skylight integrated. Generally, a skylight comes around with one of the best cost-to-benefits ratios out there in terms of upgrades. It doesn´t just improve comfort but also aids energy efficiency as well as changes the aesthetics of the RV.

Getting the right kind of skylight and properly fitting it can be a challenge at first. This article aims to provide a comprehensive guide on RV skylights and their advantages, with a focus on properly measuring an RV skylight before buying and installing it.

The benefits of an RV skylight

First and foremost, a skylight brings natural light into the RV all day long. There are two main benefits to this. First of all, having light enter the accommodation space for longer means less power drawn from the batteries or power grid of the camping site. Less energy means less money spent on either fuel or RV camping fees.

More natural light benefits the human body. Less exposure to artificial light and more natural light coming from the skylight improves health and overall mood.

A skylight improves ventilation in an RV. While fresh air is needed everywhere in an RV, installing a skylight in a bathroom or shower area drastically improves ventilation, reduces humidity, and prevents mold from forming.

There is some headroom to be gained when installing a skylight. Especially when adding a larger skylight, you can get extra headroom in the RV. Generally, skylights are installed directly into the roof and stand slightly higher than the interior roofline of the RV.

A direct view of the night sky is worth the installation of an RV skylight. While it lets natural light get in during the day, an RV skylight will provide a stunning view of the night sky when the sun sets. This is especially pleasing when camping outside of cities, where light pollution is reduced and stars are easily visible in a clear sky.

When trouble occurs, it is better to have an emergency exit that can get you outside the RV quickly and out of harm´s way. If you can´t use the main RV exit nor you manage to break a side window, going up through the roof may be your last chance. Adding an adequate skylight can provide a viable emergency exit, especially when the RV may be tipped or there may be a fire surrounding it.

Types of available RV skylights

Depending on their function, there are two main types of RV skylights: fixed dome and ventilating skylights.

Fixed dome skylights
Fixed dome skylights are generally the cheapest option to buy and install. In most cases, fixed dome skylights are built out of rigid acrylic. Their dome shape is intentional and serves more than an aesthetic purpose. The dome allows rainwater to pour down and not gather on the skylight, otherwise leading to corrosion, leaks, and bad smells.

Furthermore, the dome shape reflects more light into the RV enclosure, compared to a flat skylight. Basically, there won´t be just a spot of light projected on the floor of the RV, but rather a wider cone of light spreading inside the RV.

Most of the fixed dome skylights on the market come colored in white in order to boost light spreading on the inside. However, some models come in clear coating or black/brown tinting. If unsure whether to choose a clear or tinted dome, there is always the option for tinted covers.
Ventilated skylights
Ventilated skylights generally leave acrylic behind and opt for laminated glass and aluminum for added strength to impact and general wear and tear. Ventilated skylights come with hinges on one side, allowing them to open up slightly and allow fresh air to enter the RV.

In most cases, a screen cover is provided with ventilated skylights, allowing you to open the skylight without bugs entering the RV through the opening. Depending on the budget and integration capacity, ventilated skylights can be acquired with a manual opening mechanism or automated (usually electric) actuation.

While automated skylights are more comfortable and easier to use, they do pose additional complexity and potential for faults due to the electric actuator. In many cases, the actuator will also mean that more space is needed for installation.

Measuring a skylight

Once the decision over what kind of skylight is best suited for your RV´s needs, it is time to decide where to install the skylight. Just like a residential building, there are plenty of electric cables passing through the roof of an RV, so the placement of the skylight must be carefully chosen not to interfere with any of them.

Sawing off a cable from the roof when attempting to install a skylight can lead to hefty repair fees. Furthermore, sawing through a thinner portion of the roof is advisable as it reduces the workload.

To properly measure a skylight, depth, height, and width must all be taken into account. De depth of the skylight must first be considered to take into account various obstacles. As a rule of thumb, a minimum depth of 1.5 inches is needed for the skylight brackets and the skylight cover.

The height and width of the skylight should be measured in three distinct places:

  • Bottom of the skylight
  • Middle of the skylight
  • Top of the skylight

It is recommended to start measuring the width of the skylight in the three places, then measure the opening on the inside from one edge to the opposite.  Next up, measure the height of the skylight by the same 3-place formula. If the opening is very tall, additional mounting hardware could be required to properly install the skylight.

What´s needed to replace an RV skylight

Whether it is because of damage or looking for an upgrade, replacing an RV skylight can be done by following the guide below. First off, you will need the following:

Step ladder to reach the skylight
Painter knife to remove old sealant
Straight and Phillips screwdrivers to remove skylight bolts
Rust penetrator for potentially rusted skylight bolts

Start by removing the old sealant with the painter’s knife, then remove the screws of the old skylight. If the screws are rusted into place, apply some rust penetrator (WD-40 works just fine) and let it work for a few minutes. Continue removing the bolts and then remove the skylight.

Clean the surface of the mounting area and apply a fresh layer of caulk or sealant, then proceed to install the new RV skylight. Adding sealant on the mounting screws boosts protection but will increase removal difficulty in the future.

If any gaps remain after installing the new RV skylight, fill them with caulk or sealant to prevent leakage during rainy days. Wait the specified time for the sealant to dry then check whether the installation was successful.

In the case of broken skylights, especially for the glass part, it is highly important to dispose of the sharp edges before attempting to remove the skylight. This will prevent serious injury to one´s hands and face. Always use gloves when handling glass shards, the RV skylight structure, and the sealant. This way you will prevent contamination of skin and potential burns.


The two main types of skylights are fixed and vented. Fixed skylights are stationary and don't open or close, while vented skylights can be opened to let in fresh air.

Skylights are typically measured in inches, so you'll need to convert your width and height measurements accordingly. For example, a common size for a fixed skylight is 24" x 36".


Getting a skylight for an RV provides several benefits, particularly in terms of natural lighting. Depending on the needs of your RV and available budget, you can choose between a fixed dome skylight or a ventilated skylight. Tinted skylights are also available although a tinted cover is better suited and more efficient.

Measuring the RV skylight is critical to adequate installation and following the above-mentioned procedure for removing an old skylight and mounting a new one ensures a hassle-free, leak-free installation. Overall, by measuring and correctly installing an RV skylight, the comfort level, lighting, and RV experience will be boosted.

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Ever since I was a kid, I've been fascinated by travel. I inherited this passion from my parents. Since my college years and to this day, I have had a passion for traveling in a motorhome. I am here to share my experiences with you.

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