What VELUX flashing do I need?

Help & Advice > Project Guides > Pitched Roofing

11th August 2026

The VELUX flashing you need depends on the material of the roof and the types of finishing touches you might want. For example, choosing the correct flashing for your roof material is essential, but whether you’d like recessed or standard roof windows is entirely up to you. Other options include adding additional energy efficiency and eliminating cold bridging. Below is a small list of things you need to know in order to choose the correct one.

Table of contents

• What do the VELUX flashing codes mean?
• How to choose the right VELUX flashing kit
  • Check your VELUX window code
  • Check your roof pitch
  • What is your roof covering made from?
• Do you want standard or recessed installation?
• VELUX flashing types explained
• VELUX flashing compatibility checklist
• When should VELUX flashing be replaced?
• Common mistakes to avoid
• FAQs
• Final thoughts

What do the VELUX flashing codes mean?

You may have noticed that each flashing includes a combination of three letters (EDJ, EDN, EKP and so on), followed by a four-digit number (e.g. 1000, 2000). The number refers to the range, but what about the letters?

Let’s take a closer look:

First letter – refers to the type of product. When dealing with a VELUX flashing, this is always going to be an E.

Second letter – refers to the flashing style. The letter D stands for single flashing, B for twin, K for combi and F for sloping/vertical.

Third letter – refers to roofing material on the type of installation (more on that later). With a standard installation, the options are L for slate, W for tile, and P for plain tile. With a recessed installation, you’ll see N for slate and J for tile.

So, the VELUX code EDW, for instance, denotes a single flashing fitted on a tile roof with standard installation.

How to choose the right VELUX flashing kit

Just like how a pitched roof window must be installed between a certain pitch, flashing kits are the same. The flashing kit must match the roof pitch and naturally, then it will match the roof window. It’s essential to choose the flashing kit that’s compatible with whatever material is on the roof. Different types of tiles and materials have different requirements. VELUX manufacture flashing for tiles, slates, and plain tiles across their range of pitched roof windows.

Check your VELUX window code

The code found on your VELUX window should be identical to the one on your flashing. For example, MK04 roof windows require MK04 flashing kits. This code indicates the size of the window, which is why it is essential that you purchase flashing with the identical code, else it will not fit. Other flashing codes indicate what roof pitch the flashing is suitable for as well as the roof covering material.

Where do I find my VELUX window code?

Open your roof window. Along the sash, to the right-hand side, you will see a silver plate with information on it. This is where the window code is located.

Check your roof pitch

VELUX flashing kits have their own codes that correspond to the roof pitch and roof covering material. Each VELUX flashing kit is equipped to suit a specific pitch range. Carefully check the product description to find this information. For example, the product below is for installations between 10 and 20 degrees. Here at ROOFING SUPERSTORE, these details can be found under the ‘features and benefits’ section on the product page.

How do I find out the pitch of my roof?

You can find what pitch your roof is by contacting your local council and requesting past planning permissions or certificates.

Alternatively, if you want to calculate the pitch yourself, follow the steps below:

1. If you have access to your loft or attic space, you can measure the rise-over-run ratio. To do this, you’ll need to locate your rafters. These are the sloping, structural posts that make up the roof. They are often made from timber. Choose any rafter.
2. Using a tape measure, measure and mark the point of 12 inches on a spirit level. Place the end of the spirit level (where 0 inches would be) against the rafter, making sure it is level.
3. Now, using your tape measure, measure down vertically from the part of the rafter sitting above the 12 inch mark. This vertical measurement, where your tape measure meets the 12 inch mark on your spirit level, will be your ‘rise’.
4. Now that you have your run (12 inch) and your rise (the vertical measurement), pop these into a roof calculator like the Omni roof calculator to find the exact pitch in degrees.
5. If you’re still not sure, there are various apps to give you additional guidance.

For a 15-90° tile roof, choose the VELUX EDW flashing kit

This flashing kit is compatible with tile roofs with tiles up to 120mm in profile. The flexibility of the flashing means it’s compatible with many tile profiles, including profiles which feature many troughs and peaks. This particular flashing kit is suited to interlocking tiles, thatch tiles and profile sheet roofing too.

For a 15-90° slate roof, choose the VELUX EDL flashing kit

Use this flashing if you have a slate roof with profiles of up to 8mm thick. Unfortunately, this kit isn’t compatible with interlocking slates, for this, you should use the EDW kit mentioned above.

For a 25-90° plain tile roof, choose the VELUX EDP flashing kit

VELUX EDP flashing kit is compatible with any plain tile roof with a minimum pitch of 25 degrees. There is also a maximum length of plain tile this flashing is compatible with – 300mm. Plain tiles can’t be above 14mm for this flashing to be effective.

For a 10-75° tile roof, choose the VELUX EAW low pitch flashing kit

These kits are for tiled roofs with a maximum profile of 120mm. Sometimes known as a VELUX mini dormer flashing kit, it is designed for use with roof windows in a roof with a minimum pitch of 10 degrees. The usual minimum roof pitch for VELUX windows is 15 degrees so this flashing gives a lot of flexibility in design for low pitch roofs.

For a 15-90° roof of any other substrate, including lead or standing seam sheeting, choose the VELUX ZWC special header flashing kit

VELUX does offer a flashing kit for non-traditional roof materials. If a roof isn’t slate or tiles it can still benefit from the looks and the light of a VELUX pitch roof window by utilising the ZWC flashing kit. This flashing kit is designed to overlap the roof material with a hood-like special head flashing. The installer then just needs to flash up to the window frame to ensure weather tightness. It’s not necessarily a flashing, it’s a covering to allow for flashing on a non-traditional roof.

Please note: ZWC flashing can also be used when installing a VELUX pitch roof window into a self-built timber kerb on a flat roof.

What is your roof covering made from?

VELUX flashing codes also help you identify what roofing material they are suitable for. The third letter in the code indicates this, as explained in the ‘what do VELUX flashing codes mean?’ section above. Selecting your flashing type will depend on whether your roof is made from slate, slim profile tiles, plain tiles, interlocking tiles, or thatched.

Do you want standard or recessed installation?

Another factor you’ll need to consider is whether you are installing standard, single roof windows, or combination/side by side/stacked roof windows. You can install VELUX pitch roof windows one of two ways, and this totally depends on the final look you want. Opt for standard installation will mean the window will protrude around 30mm from the roofline. You must fit a recessed window 40mm deeper into the roof so the outside sits flush with the tiles. This gives a more streamlined and, in some opinions, a better-looking finish. To achieve a recessed finish you need a different flashing kit.

For single roof windows, we have carefully curated a range of standard flashing that is all in one place. We’ve efficiently separated our combination flashing kits into their own range, and you’ll often see VELUX defining them by including ‘twin’, ‘duo’, ‘coupled’, ‘triple’, ‘quattro’, or ‘combination’ in the title. VELUX combination flashing includes kits that house up to four windows. Remember, you still need to select the compatible roof material, pitch, window code.

For a 20-90° tile roof, choose VELUX EDJ recessed flashing kit

For tile roofs with tiles up to 90mm thick, opt for a VELUX EDJ recessed flashing kit for a flush-fit pitch roof window. You must install this flashing on a roof with a minimum of 20 degrees so, unfortunately, roofs under 20 degrees aren’t compatible with installing recessed windows.

For a 20-90° slate roof, choose VELUX EDN recessed flashing kit

You can use this flashing kit on slate roofs with a maximum slate thickness of 8mm. You cannot use it on roofs with interlocking slates so be wary of what type of slate you have before purchasing.

VELUX flashing types explained

One of the defining factors of VELUX flashing kits is what your roof is made of. Below are the different options and which roofs they are suitable for.

VELUX flashing compatibility checklist

The list below will help you identify the correct flashing kit for your VELUX window. It is essential that the flashing meets all of the criteria.

• Make sure the code matches. For example, if your roof window has the code MK04, you need to purchase a flashing kit that has the identical code, MK04. Note: This code reflects the window’s size, which should also match the flashing size. For example, if the window size is 78cm x 98cm, the flashing should also be this size.
• The roof covering type. For instance, slate, tile, plain tile. This should be stated in the product title.*
• The roof pitch.
• Are you installing single or combination windows?
• Do you want a standard or recessed fit? If recessed, you must check if your window and roof are compatible.

*Some exceptions may be found in product descriptions, like the VELUX Pro+ EAW Low Pitch Tile Flashing is also suitable for interlocking slate and thatched roofs.

When should VELUX flashing be replaced?

If you are concerned that your roof window is leaking, or detect any water ingress, we recommend checking to see if your flashing is damaged. This can come in the form of corrosion, cracks, gaps, the flashing edges being ‘lifted’, or even water marks on your ceiling. It is definitely worth contacting a professional if you are unsure.

Another reason to replace your VELUX flashing is if you are having your roof covering changed. For instance, if you are changing your roof from plain tiles to slate, you’ll need to purchase a new flashing kit for slate roofs.

Similar to changing your roof covering, if you are upgrading your existing roof window, you will also need to replace the flashing. It is always best to opt for the most recent release that is compatible with your window size, code, roof covering, and pitch.

Although it is rare, there could be a chance that your flashing was installed incorrectly, or the flashing itself is faulty. If you suspect this, contact your installer immediately, or the flashing stockist. Don’t forget, VELUX flashing comes with a 10-year guarantee.

Common mistakes to avoid

Many property owners make the common mistake of buying their new VELUX flashing based on the window code alone. Therefore, it is important that you do not:

• Decide which flashing to buy based on just the window size
• Avoid checking your roof pitch
• Ignore what roof covering material the flashing is designed for
• Purchase single flashing kits if you’re fitting combination or stacked roof windows

FAQs

• What VELUX flashing do I need?

The VELUX flashing you choose depends on your VELUX window code, your roof covering material, your roof pitch, and whether you are installing single roof windows or combination windows. This information can be found in the product titles or in the descriptions. If you’re still unsure, please give our expert team a call on 01752 692 760 and they will be able to tell you exactly what you need.

• Are VELUX flashing kits universal?

No. We do not recommend using VELUX flashing in combination with other roof window brands. VELUX flashing is specifically engineered to fit the dimensions and window structure of the VELUX brand.

• What is the difference between VELUX tile and VELUX slate flashing?

The main differences are the bottom apron and profile depth. Slate flashings tend to be much slimmer, whereas tile flashings feature a bottom apron in order to bridge the wider gap. Tile flashings are also manufactured so that drainage is much easier. Tiles require a more complex system in order to guide rainwater away from the window opening.

• Can I reuse old VELUX flashing?

No, we do not recommend you use old flashing. If you’re installing new roof windows or fitting a new roof, it is likely that your flashing will no longer be compatible with the pitch, roof covering, or window code. Even if it is, it is always best to purchase new flashing as it can invalidate the guarantee on your new VELUX windows. What’s more, your old flashing may be worn or damaged, even without you realising, resulting in an incorrect installation.

• Do I need different flashing for multiple VELUX windows?

Yes. When fitting new roof windows side by side, whether that’s vertically or horizontally, you must opt for combination flashing. If you are fitting single roof windows that are not being installed directly next to each other, opt for multiple standard flashings suitable to the amount of windows you’re fitting, roof pitch, covering, and window size.

Final thoughts

Knowing what to consider before purchasing your VELUX flashing kit is essential. As long as you have checked:

• Roof pitch
• Window size
• VELUX window code
• Roof covering material (tile, plain tile, slate, thatched)
• Whether you are fitting combination or standard roof windows

You should feel confident in which flashing is right for you. Keep the ‘What do VELUX flashing codes mean?’ section at the beginning of this guide handy when browsing, as it can be a lot to remember! And as always, if you’re looking for expert advice, please give our excellent customer service team a call on 01752 692 760, and they can even provide you with a free quote tailored to your project.