Curb Mount Vs. Deck Mount Skylight: Which Is Right For Your Home?

Ryan Womeldorf
by Ryan Womeldorf

A skylight can be a beautiful addition to a home. In addition to providing a beautiful look at the sky, they can help give an infusion of natural light and can help keep homes warmer during the colder months of the year.

But there are two types of skylight: curb mount and deck mount. Curb mounts sit on top of a framed opening while deck-mounted skylights fasten to the roof sheathing itself. The one best for your home depends on the setup of your roofing.

We are going to learn the differences between the two so that you can install the right one if you do it yourself.

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Curb Mounted Skylights

Curb-mounted skylights are the most common type of skylight around. They have a requirement of less than 14 degrees if they are going to be installed on sloped roofs.

This is the kind of designed that needs a type of box structure for the skylight itself to sit on can work on different styles of home.

Generally speaking, the box used for this type of skylight will be somewhere in the 2×6 range, but it can be larger.

Using construction lumber, it is set on edge before being attached to the roof deck. Lastly, the box is “flashed in” using additional roofing material to make sure that it is properly waterproofed.

What Is The Design For Curb Mounted Skylights?

The design of this skylight is that it is meant to sit over the “curb” in a similar fashion to the way that the lid of a shoebox fits. The benefits to this is that you can replace older skylights with no need to reflash the skylight, too.

This means that there are fewer labor requirements when installing a curb-mounted skylight. Best of all, it is easy to manufacture any size that you want.

Whenever the flashing is working properly but the skylight needs to be replaced, this is the type of skylight you would go with.

The only downside here is that it creates a profile that can stick out noticeably. Not only that, it is also less energy efficient because they are not generally insulated aside from the thickness of the installed curb.

Recommendations For Curb Mounted Skylights

If you do decide to go with a curb-mounted skylight, there is one recommendation worth considering. The National Roofing Contractors Association has a recommendation of using a curb that will allow 4 inches of vertical flashing one every side.

When installing on a low-slope roof, it is a good idea for the flashing to be even taller; up to 8 inches or so. If the curbs that are manufacturer-produced don’t meet these requirements, there will be a need to extend the curb’s height.

Deck Mounted Skylights

In contrast, these types of skylights are most suitable when the slope of the roof is 14 degrees or more. These are a more modern design that is meant to lower the profile that is created by using a curb mounted skylight.

Even better they increase the overall efficiency since they are so much closer to the roof than curb mounted skylights. There are even flashing kits that have been developed throughout the years to improve the overall quality and energy efficiency of these units.

The lower profile of the deck-mounted skylight is meant to provide a greater appeal visually both on the exterior and the interior.

Not only that, the improved energy efficiency is a selling point in times where such a thing is of the utmost importance. You will find deck mounted skylights in most modern constructions.

The Pros Of Installing A Skylight

There are quite a few advantages to installing a skylight. The introduction of natural light can make a room feel bigger than it is, brighten up rooms that don’t get enough natural lighting and provide ample ventilation for humid rooms.

Additionally, skylights are great for colder regions. They bring in more natural sunlight through the winter, heating up the home without the use of a furnace. That can help save quite a bit on utility bills when the weather turns frigid.

The Cons Of Installing A Skylight

Like anything else in life, there are downsides to having a skylight installed in your home. Be careful to limit the amount of exposure that furniture and flooring gets. The sunlight can fade and wear down those things, requiring replacement sooner rather than later.

And even though they can help mitigate heating costs, an improperly installed skylight can have the inverse impact.

A skylight can lose some heat, let in condensation or leak altogether. Thankfully, there are easy ways to avoid these problems.

What Are Fixed Skylights?

There are three different kinds of skylights. The first is your fixed skylight. This is the kind of window that will not open. They are meant to provide a view of the local scenery, the sky, and to provide additional lighting.

These are the kinds of skylights that will be installed on high ceilings where they can’t be reached. Since they don’t open, they won’t work for combatting humidity in a room, so be aware of that before having this type installed.

Vented Skylights

These look the same as the aforementioned fixed skylights, but they can be opened. Best of all, these skylights can open either by hand or through the use of an electronic control of some type. This is the kind of skylight meant to keep excess condensation or humidity at bay.

They provide moisture control in rooms like the kitchen or bathroom and even have use as an emergency exit if that are accessible and have been constructed up to current building codes. They are also much more expensive because they require more work than a fixed skylight.

Tubular Skylights

Also known as solar skylights, these are the least traditional of the three. These are actually elongated tubes that not only catch light but reflect it into your house. This makes them quite good for small spaces (think hallways, bathrooms, and closets).

Solar skylights are easy to install and they will fit between any obstructions plus they have dimmers that can control how much light they let in. Some even come equipped with exhaust fans in order to mitigate the moisture levels of a room.

The only downside to tubular skylights is that they won’t let much natural light in, and you won’t get much of a view through them. Still, for privacy and all the other benefits they provide, tubular skylights are becoming a more popular option.

Flat Skylights

There are also different styles of skylight as well. Flat roof skylights are flat but they also follow the pitch of your roof. Flat skylights are usually deck-mounted so that they won’t protrude and impact the look of your roof line.

Round Skylights

Even though these skylights have a flat exterior, they have a round shape when viewed from the interior of the home. Best of all, they are versatile. This type of skylight can be either curb or deck mounted and they can provide a little bit of a different look from other skylights since they aren’t quite as common.

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Dome Skylights

This is the kind of skylight that will project upwards, coming into the shape of a dome. On the inside of the home, these lights look rectangular but come in styles that will make them look like they are domed as well.

This kind of skylight is generally plexiglass and makes it more resistant to storm damage like hail. Dome lights are also quite inexpensive to install and even usable on flat roofing system. That makes dome lights an easy choice for those looking to have multiple skylights installed.

Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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