Last Updated on August 17, 2023 by legacy450

The term Tongue and Groove siding refers to the edge profile that is milled into each individual wall board. On one edge, there is a tongue design cut specifically to fit into a groove cut on the opposite edge of the board. This specific profile allows the boards to stack together resulting in an easier installation (versus traditional lap or clapboard siding) and creates a tight seal to keep natural elements such as rain, snow, and wind away. This profile can be milled into several wood species and siding patterns which are covered in this article.

What Wood Species?

A tongue and groove profile can be milled into several species of wood for exterior siding applications. The most popular species for exterior siding are Western Red Cedar, Cypress, and Pine. It is possible to find other natural wood species that have this profile such as Douglas Fir but that will depend on the region of the country. Wood species with this profile better suited for interior use include Spruce, Southern Yellow Pine, and White Pine.

Siding Patterns with Tongue and Groove Design

There are several siding patterns (siding styles) that feature a tongue and groove design, but here we will concentrate on the three most popular exterior designs including the V-Joint, Nickel Gap, and Square Edge. These three patterns are versatile as they can be installed horizontally, vertically, or diagonally.

There is a fourth product with a tongue and groove profile that is an edge and center bead product (also known as Beadboard). This product can be used on the exterior of a house but is typically used for porch ceiling and soffit applications, not typically as a siding pattern.

Tongue and Groove V-Joint Siding

Most local retail building suppliers (not your national big box store) will stock the v-joint pattern. This pattern has a 45 degree V chamfer cut on the leading edge of both the tongue and the groove side so when the siding is installed it will provide a pronounced V groove where the boards meet. The material will come with either a smooth face or rough sawn face. It is possible to find material that has one side smooth and one side rough (known as S1S2E or surfaced 1 side and 2 edges). Both Cedar and Cypress versions are obtainable and can be created in several grades depending on desired look and budget.

Cypress Tongue and Groove V-Joint Rough Sawn Face

Nickel Gap Tongue and Groove Siding

Nickel Gap siding is another exterior siding design where the tongue is cut shorter on one side than the other. When the short side of groove is installed facing out, it will produce a nice nickel width gap between the boards for a unique thin shadow line look (see below). This pattern is most commonly produced with a smooth face producing a clean, modern look. Both Cedar and Cypress versions are obtainable and can be created in several grades depending on desired look and budget.

Cedar Tongue and Groove Nickel Gap Siding

Square Edge or No-Gap Tongue and Groove

Using the same Nickel Gap material, the boards can be flipped so the long end of the groove is facing out giving a square edge no-gap look (smooth face product). There may still be a slight visible line when viewed from close range but from a distance, the final siding design looks like a solid wood wall. This pattern is most commonly produced with a smooth face giving a clean, modern look. Both Cedar and Cypress versions are obtainable and can be created in several grades depending on desired look and budget.

Tongue and Groove Bead board

This material has a tongue and groove profile with a v-joint design on one side while the other has an edge and center bead. This design is good for a porch ceiling or soffit application as you can use either side as the finished side (both sides are smooth face). These products can be prefinished with a stain, primed and painted a solid color, or primed so it can be painted with a solid color on the job site.

Spruce Tongue and Groove Edge and Center Bead – Legacy Porch Blue

Benefits of Prefinishing Your New Siding

We highly recommend prefinishing your new tongue and groove siding for a number of reasons. This material is a natural wood product so it will expand and contract with the weather. If the material is installed and then stained or painted afterwards, there is a chance that when weather cools and the boards contract, you may see a small line of unpainted wood at the joints (known as shrink lines). This is seen more on porch ceilings than siding. To prevent this, the material is ordered prefinished (in your choice of primer, stain or solid color paint) where the finish is applied to all sides of each board (also known as backpriming). Prefinishing also protects the wood from moisture since it arrives on the job site finished; the material is not subjected to sunlight that can cause the wood to weather leading to additional costs to prep the siding before painting on site.


Whether you decide to use the v-joint, nickel gap, or no-gap square edge pattern, either one is sure to give your home outstanding curb appeal. The natural warmth and beauty of real wood is hard to beat so to keep your home looking its best, have the material prefinished before installing it. Make sure to seal all cuts and any raw wood exposed during the installation process to prevent moisture intrusion. For general installation guidelines please see the following links and remember to follow all local, county, and state building codes.

Installing Western Red Cedar Tongue and Groove Siding – from

Cypress Siding Installation Guidelines – from

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