The Ultimate Guide to Roof Scuppers: What Is a Roof Scupper
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The Ultimate Guide to Roof Scuppers: What Is a Roof Scupper

The proper drainage amount and system of any roof is the most important factor to consider. You need to make sure that rain and other water can drain off your roof to avoid any damage to it. There are several ways to channel water through your roof, such as cuppers and traditional roof drains that are typically used together. So, what exactly is a roof scupper?

Roof scuppers are designed to allow water that collects on the roof surface to be drained away from the interior of the building quickly and efficiently. They are also used to eliminate the need for gutters, reducing potential maintenance costs and improving the aesthetic appeal of a building’s exterior.

what is a roof scupper

What is a Roof Scupper?

A roof scupper is classified as part of the drainage methods for roofs which has an opening on the wall. It is usually constructed of sheet metal, which allows water to pass through a rectangular hole that is rectangular at the roof’s edges.

The use of a roof scupper can reduce the amount of water flowing through a roof drain by up to 50%, making it an efficient choice for controlling runoff. Additionally, if designed well, they can provide an aesthetically pleasing look as they are usually rectangular or square in shape and blend in well with the building’s architecture.

Roof drains as well as roof scupper drains are often believed to be comparable because they are both designed to prevent standing water but they’re different in reality. Scuppers and roof drains are different in that the roof drain utilizes pipes that actually work, and a scupper is designed to allow water to exit from the top of its spout along the sides of the structure. Scuppers typically are located on the wall of the parapet.

Roof scuppers are utilized for a variety of styles of construction. However, generally, you’ll find them in most commercial buildings and apartment buildings. Roofs with flat surfaces often include them.

Roof scuppers are most commonly seen in commercial buildings and industrial facilities, but they can also be used in residential homes. In some cases, a roof scupper may be the only drainage system needed for a roof – such as when an area of a flat roof is not connected to any other areas or structures.

There are numerous advantages of the use of a scupper in conjunction with the roof drain. However, there are other advantages to the use of a drain on a roof over the one. Both of them can serve as an alternative to a proper roof drainage system though. What is the best one to be employed in the building of a house is determined by factors like the type of roof you’ve got and the construction and building codes with which you require your drainage system for roofing to comply.

Why You Need to Know the Difference Between a Roof Scupper and a Drain

You’ll be amazed at the distinction between a roofing scupper as well as a roof drain. It is likely that they’re very like items that you have in your roof drainage system for your roof.

A roof scupper can be an element of your roof drainage system. It allows water to flow off of the roof by passing through a metallic edge, a parapet wall, or even through the roof and into the downspout. This prevents the water from leaking through the inside of your building when it collects over the roof edge.

Roof drains are systems where water runs off flows across the roof drain, and into the side piping system which runs onto the outside of the structure. Drains for roofs are installed on the middle of the roof and then joined to pipes that be able to pass through the attic, and through the building’s sidewall to the exterior wall of the building.

The Complete Guide to Different Types of Roof Scuppers

The Complete Guide to Different Types of Roof Scuppers

The scuppers for roofs typically come in two different shapes and forms, such as an open scupper (a three-sided scupper that has an open top or “channel-type” scupper), or the one that runs through to the wall (basically it’s a hole in the wall that typically has the rectangular form).

Sometimes, you’ll see an asymmetrical flat roof Scupper or a beautiful scupper in a distinctive form.

Protect your building against water damage with thru-wall roof scuppers

Through-wall (or “thru-wall”) scuppers are usually covered with sheet metal, like galvanized steel, or copper. The use of aluminum isn’t common as it is more challenging to create and then solder aluminum at the site as compared to other metals utilized for roof construction.

The metal part is referred to as a “scupper box”. It is integrated into the roof (flashed or “stripped in”) on the inside of the wall. It generally ends up on the outside of the wall by an exterior faceplate that has sealant on the edges.

Keep your building safe with channel-type roof scuppers

Channel-type roof scuppers are also usually lined with steel, however, the metal is joined into the coping or another edge of the metal, and integrated into the roofing membrane.

Infrequently, different materials like the liquid-applied waterproofing compound, are utilized to cover the roof scupper’s hole.

In most cases, when using single-ply roof membranes like the TPO roof and EPDM The roof membrane material extends inside the scupper box, covering the entire surface of the scupper that is bonded to the steel.

Protect your property with an effective roof drainage system

Protect your property with an effective roof drainage system

Scuppers play two purposes in a roofing system. They will constitute a component of the primary drainage system for the roof or a component of the second (overflow) rooftop drainage.

The main drainage system can be constructed to drain water off the roof as swiftly as possible during heavy rain.

A drain system for overflow can be developed to function as a second, complete drainage system that functions in isolation from the main system.

The main function of an overflow proper drainage system is to remove excess water up from the roof when the main drains or scuppers are blocked so that the structure of the roof isn’t overwhelmed by the weight of the water. In the event of overloading, it can cause damage to the structure of the roof and even collapse of the roof.

Take note that if you’re sitting on the ground and glance upwards and notice that the scuppers on the wall’s parapet are single scuppers, then those smaller scuppers that are on the roof may be part of the secondary drainage system. The roof could have internal drains.

If the scuppers exist closely grouped each time, one of them is usually a component of the main drainage system, while the next one is an overflow scrubber.

Sometimes, you will find two scuppers close to one another, which each serve the same function and have the same size above the roof. The most common reason is when insurance companies determine that the initially licensed roofing contractor or scupper was not large enough because of code adjustments or modifications to their loss prevention policies.

In this case, the building owner is required to boost the capacity of drainage systems by expanding the scupper holes or adding additional scuppers to the ones already in place.

Location of Primary Scuppers

Location of Primary Scuppers

Primary roof scuppers serve to replace internal drainage channels on roofs (for many reasons). The primary scuppers would be the primary drainage component for the areas of the roof they service.

Scuppers included in the primary drainage piping system are placed so that the lower edges of the roof scupper hole coincide with the surface of the roof.

Roofs of all kinds (even “flat” roofs) are sloped down towards the main scuppers. The scuppers will be placed on the parapet wall, at the bottom of the roof.

Location of Secondary (Overflow) Scuppers

Scuppers which are part of the drainage system can also be found in the lowest areas of the roof. They are only slightly higher than the surface that is the roofing surface.

They’re usually located near the wall of the parapet that is closest to the main drain that is in place for the region. The overflow scupper should be placed closest to the main drain as it is able to be so that it drains from the same area of the roof as it does when the drain is blocked.

If scuppers serve to drain the main drainage system in lieu of regular maintenance of internal drains the overflow scuppers are likely to be located close to or directly next to primary scuppers, which are draining from the same roof, however, the top of the secondary scupper holes would approximately two inches larger.

There are times when water isn’t able to flow the gutter system directly into the wall due to obstruction (such as an uncurbed expanding joint like a curbed expansion joint) between the main pipe and the wall. If this is the case, an overflow scupper is installed at the lowest, closest section of the drainage system backs the wall, where water is able to direct flow from the drainage location.

The edges of the bottom edge of scuppers for overflow found on buildings are usually approximately two inches higher than the metal edge of the roof surface.

This will prevent the overflow scuppers from serving as drains primarily.

Overflow scuppers are only supposed to be flushed off the roof when the main drains or scuppers have been blocked and water has accumulated onto the roof as a consequence.

Roof Scupper Code Requirements

Roof Scupper Code Requirements

There are a variety of code guidelines for scuppers based on the function they perform.

It’s crucial to know that the terminology for both primary and overflow cups in the latest version of the International Building Code stipulates that: “the quantity, size, location and inlet channel water and elevation of the scuppers shall be chosen to prevent the depth of ponding water on the roof from exceeding the maximum of water pooling depth that the roof was designed for as determined by Section 1611.1 of the International Building Code”.

It’s not a great idea If you don’t possess the specifications for the structural design of the structure.

The principle that the top of the scupper needs to be 2 inches higher than the ceiling was standard practice within the roofing industry for a long time and could remain the code for some areas dependent on the particular model of code that is currently being used.

A scupper drain is a roof drainage system where the water runs through an opening in the wall or parapet of a building, allowing it to flow directly to the ground. Scuppers are typically placed along the perimeter of flat roofs or other areas with large rainwater accumulations. They are designed to redirect rainwater away from vulnerable areas where it may cause damage and allow it to be safely discharged away from the building.

A Guide to Choosing the Right Roof Scupper Size

The only absolute guideline for the roofing size of scuppers that is provided in the code is that “scupper openings shall be not less than 4 inches (102 mm) in height and have a width that is equal to or greater than the circumference of a roof drain sized for the same roof area.”

We can, at a minimum, ensure that scuppers of round shape cannot have diameters that are smaller than 4 inches. Rectangular Scuppers shouldn’t be lower than 4 inches.

If you know the proper size of an appropriate drainage for your own licensed roofing contractor you are able to easily determine what size is required for an equivalent roof scupper by following the above-mentioned guideline.

If you’re looking to set up an overflow scupper to an area on the roof that already has a drain on the roof, and you’re certain the roof drain you have is of the correct size as that is required to be used by code it is possible to make use of this 4 inches by circumference prescribing to figure out the dimension of the new scupper.

If you’re seeking comprehensive technical specifications on sizing and positioning the scuppers, FM’s “DS 1-54 Roof Loads for New Construction” (Data Sheet) is a fantastic source (see the hyperlink below).

Roof Scupper Tips

Keep your scupper safe and sound with these maintenance tips

Sealant Deterioration: The sealing agent around the flange or faceplate of the external wall surface within a thru-wall screw is an essential maintenance piece.

Sealant deteriorates over time. It’s crucial to assess the quality of this sealant annually and then replace it as soon as it begins to wear out.

The sealant is a crucial part of stopping leaks from the roof. It prevents water from leaking between the scupper box made of metal and wall masonry before it re-enters the roof structure and eventually into the structure.

Don’t Let Clogged Drains Ruin Your Day

Blocked drains Scuppers utilized as the main drainage component usually funnel water through the downspout, a conduit box, or an encasement system (you don’t want to be able to watch the water runoff transfer off dripping through the walls of your property or pouring into the air in the form of mini waterfalls).

If the roof drains in your interior are the primary system for proper drainage and the scuppers function as your second drainage option then you should need to observe these water drains flowing out of the roof scupper because it indicates that the drains in your home are blocked.

That’s why the overflow scuppers really are holes in the wall, without an electrical conductor head or downspout. An efficient primary system can provide you with a clear perspective of the open overflow roof scupper.

It is important to check whether the water comes out of the drains, so you will know immediately whether you should get your main drains cleaned.

Also, you should inspect your roof scupper, as well as the drains on your roof at least two times each year in the course of routine maintenance for your roof. Clean up any debris that you can to avoid clogging and increasing the possibility of excessive water building up on your roof.

Keep your scuppers ice-free this winter with these simple tips!

Ice build-up in colder regions, the build-up of ice on the roof scupper during winter months can cause problems.

Because the scuppers are located in the wall, and not above the heated portion of the structure They are more frigid than the rest of the roof.

Snow melts and the roof can refreeze on the roof scupper, and cause water drainage. This can cause roof damage. It’s essential to have your scuppers cleaned and checked when this happens.

Replacing your Roof? Don’t forget about Scuppers!

Re-Roofing: The roof scupper that is currently on a parapet wall be designed to match the maximum height of the parapet walls initially (or earlier) used roofing codes for the area.

The recent changes in the energy and building codes also call for greater R-values and, consequently, thicker roofing insulation this is why if you’re changing your roof system then the surface of your new roof could be greater in comparison to the surface of the previous roof.

The primary thru-wall scuppers may be partly or totally blocked by the roof that has been replaced and the scuppers for overflows will never be of an appropriate size.

What are Alternatives to Scuppers?

What are Alternatives to Scuppers?

There are a variety of alternatives to scuppers that can be employed to eliminate the water off of a flat commercial roof that is low-sloped or not. A few of the most common options include:

  1. Drains for roofs: Roof drains are used to drain water from roofs, however, they’re typically situated at the middle of the roof, not on the edges. Roof drains are efficient in draining huge amounts of water over scuppers. This is especially true in the case where the roof isn’t inclined enough to permit water to flow toward the edges.
  2. Gutters They are a kind of drainage system that typically is used for sloped roofs. However, they is also a possibility to use for flat roofs or those with low slopes as well. Gutters are placed on the outside of the roof. They are intended to catch and funnel water away from buildings.
  3. Drainage systems for internal use There are some buildings with internal specifically designed to capture and direct water off of structures. They are better at preventing water destruction as opposed to external drainage systems because they are able to channel water away from places that aren’t accessible to the exterior of the structure.


What is the difference between a scupper and a drain?

Roof scuppers possess distinct characteristics as do drains for flat roofs. The flat roof drain channelizes water across a deck of a roof into a pipe system, that directs it to the outside and allows the water to flow out of an outlet.

What is the difference between a scupper and a gutter system?

Scuppers fill up with water from rain very rapidly when draining traps are filled with needles. The reason is that they are made of surface water flowing beneath the panels of face flashing. Scuppers make flat roof maintenance less difficult and they can be easily cleaned.

Where do you put a scupper on a roof?

The place of each dinner is exactly the same in the flat roof primary location. The shelters are placed on the flat rooftop’s walls and are arranged in a single direction, below the wall surrounding it.

What is a scupper?

Nouns. Scups are a result of the word kpr. A cut in the ship’s hull in order to let water out of the hull. An opening in the walls through the hull through which water escapes through the floor.

Can You Add Scuppers after a Roof is Put On?

There is a way to attach the scuppers onto a roof once it is installed but it’s a difficult procedure that requires the knowledge of a qualified flat roofing professional. In addition to scuppers, a roofing structure usually requires cutting out openings within the roof, and then putting the scuppers within the openings.

It can be a difficult project based on the structure of the roof as well as where the scuppers are placed. Furthermore, it might be required to make further adjustments to the roof or the primary drainage system in the building to allow for the new expansion. Because of the complexity involved in the process, it’s recommended to speak with an expert roofing contractor and/or engineer when you’re thinking of the addition of scuppers to your existing roof. They can evaluate the feasibility of the idea and give advice on how to go about it.


Roof scuppers play an essential role in the construction process and also as a water drainage method, no matter if they are used for the main drainage method or as a backup alternative.

They’re inexpensive and simple to set up, and it could benefit your home by having them on the roofing code proper spot. They do have disadvantages of their own and the most effective roof protection against water typically requires roof drains as well as roof.

The building you are in depending on the building, you may be able to control water through the roof by using only one or both.

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