When people talk about timber cladding, they often focus on the species — cedar, Thermowood, larch and so on. The profile matters just as much. Two of the most popular options for modern exterior cladding in the UK are shadow gap and V-groove (also called TGV or V-joint).
Both use tongue-and-groove boards. Both can look excellent. They create quite different visual effects and behave slightly differently on the wall. This guide explains the differences clearly so you can choose the right profile for your project.
At Harrogate Flooring we specialise in shadow gap cladding in Western Red Cedar, Thermowood pine and Ayous Thermowood. Understanding how shadow gap compares with traditional V-groove helps explain why so many contemporary projects prefer it.
What Is V-Groove Cladding?
V-groove cladding (tongue-and-groove V-joint) has a small chamfer or “V” cut along the edge of each board. When two boards meet, they form a neat, shallow V-shaped line.
Key characteristics:
- Classic, widely used profile
- Relatively subtle joint line
- Good water run-off at the joint
- Familiar look on both traditional and modern buildings
- Usually straightforward to install
The V creates definition between boards without making a strong graphic statement. It has been a standard exterior and interior cladding profile for many years.
What Is Shadow Gap Cladding?
Shadow gap cladding also uses tongue and groove, but the joint is designed to create a wider, deeper recess between boards. Light falls into this recess and creates a distinct shadow line — hence the name.
Key characteristics:
- Stronger, more contemporary visual rhythm
- Clear horizontal (or vertical) lines across the elevation
- Modern, architectural appearance
- Still uses a secure tongue-and-groove joint
- Excellent for clean, minimal designs
The shadow gap profile is especially popular on new builds, extensions, garden rooms and commercial projects where a crisp, modern look is required.
Side-by-Side Comparison
| Feature | Shadow Gap | V-Groove (TGV) |
|---|---|---|
| Joint appearance | Wider, deeper recess – strong shadow line | Narrow V – more subtle |
| Overall look | Contemporary, graphic, architectural | Classic, quieter, more traditional |
| Visual rhythm | Bold horizontal or vertical lines | Softer board definition |
| Water shedding | Good when correctly detailed | Generally very good |
| Installation | Tongue & groove, similar skill level | Tongue & groove, familiar to most installers |
| Best for | Modern houses, extensions, clean elevations | Traditional and mixed-style projects |
| Popularity | Growing strongly on contemporary work | Long-established standard |
Both profiles can be installed horizontally or vertically (subject to the specific board and manufacturer guidance).
Appearance and Design Impact
V-groove gives a more continuous timber surface with gentle definition between boards. From a distance the wall can read as a relatively calm plane of timber. Up close you still see the individual boards, but the joints do not dominate.
Shadow gap deliberately emphasises the joints. The regular shadow lines create a stronger pattern and a more “designed” appearance. This is why architects often specify shadow gap on contemporary projects — it reinforces clean geometry and modern proportions.
If your elevation is large and simple, shadow gap can add interest without clutter. If the building already has a lot of detail, or you want a quieter timber skin, V-groove may feel more appropriate.
Weather Performance and Detailing
Both profiles rely on correct installation far more than on the shape of the joint alone.
Important factors for either type:
- Ventilated cavity behind the cladding
- Appropriate fixings (usually stainless or high-quality coated)
- Correct ground clearance and flashings
- Careful detailing at windows, doors and corners
- Boards allowed to move with seasonal changes
V-groove has a long track record of shedding water effectively. Shadow gap also performs well when the recess is designed properly and the tongue-and-groove engagement remains sound. In both cases, poor ventilation or trapped moisture will cause problems regardless of profile.
Installation
From an installer point of view the two systems are similar. Both are tongue-and-groove, both are typically secret-fixed or face-fixed according to the product, and both need accurate setting out for a professional result.
Shadow gap can be slightly more revealing of unevenness because the wider joint makes any deviation more visible. Good quality boards and careful workmanship therefore matter. V-groove is a little more forgiving in that respect, which is one reason it remains popular.
Which Should You Choose?
Choose shadow gap if:
- You want a clearly modern, architectural look
- Strong horizontal or vertical lines suit the design
- The project is a new build, extension or contemporary renovation
- You like the defined “board and gap” rhythm
Choose V-groove if:
- You prefer a quieter, more traditional timber surface
- The building has mixed or period character
- You want a proven, widely understood profile
- Subtle board definition is enough
Many of our customers choose shadow gap precisely because it feels current and clean while still using real timber.
Our Shadow Gap Cladding Range
We supply shadow gap cladding in:
- Western Red Cedar – naturally durable, beautiful colour, weathers to silver
- Pine Thermowood – heat-treated for stability and durability, excellent value
- Ayous Thermowood – clean, largely knot-free, lightweight and modern
All are tongue-and-groove shadow gap boards, available with nationwide delivery from Yorkshire.
Final Thoughts
Shadow gap and V-groove are both excellent cladding profiles. The decision is mainly aesthetic: do you want strong, contemporary shadow lines, or a more subtle classic joint?
Looking at samples on the actual wall (or at least in similar light) is the best way to decide. If you would like advice on which profile and timber combination suits your project, get in touch — we are happy to help.
Related products:
Western Red Cedar Shadow Gap
Pine Thermowood Shadow Gap
Ayous Thermowood Shadow Gap
Exterior Cladding Collection