Tongue and Groove Roof Decking: All the Facts You Must Know (2022)

Tongue and groove roof decking, especially the one from solid wood boards, is one of the two most common choices for residential use right now. The other one is plywood.

Tongue and Groove Roof Decking: All the Facts You Must Know (1)

If right now, you are thinking about which deck choice to add to your new roof design or to replace the old or damaged one, you are in the right place. In this article, we are going to discuss roof decking with T&G style from solid wood specifically.

Here, you will find all the facts that you need to know about the deck type. Let us start with the short yet understandable definition of roof decking first to let you know about what this part is actually.

Table of Contents

  1. What Is Roof Decking?
  2. What Is Tongue and Groove Roof Deck?
  3. The Use of Tongue and Groove Roof Deck
  4. The Benefits of Solid Wood Tongue and Groove Roof Deck
    1. Strength and Durability
    2. Natural Appearance
    3. Installation Process Time Saver
  5. Design Ideas
    1. Pine Tongue and Groove Deck in a Rustic Porch Design
    2. Douglas Fir Tongue and Groove Deck in an Eclectic Living Room
    3. Pre-finished Pine Tongue and Groove Roof Deck in a Rustic Entry Interior with Loft
  6. Closing

1. What Is Roof Decking?

Tongue and Groove Roof Decking: All the Facts You Must Know (2)

If being asked about the definition of roof decking, here is the simple explanation that we can give to you. It is an element which location is in between the components of the structure (the joists and trusses), the weatherproof layers (the materials of the roof, underlayment, and coatings), and the insulation.

To make the definition clearer, you can take a look at the picture above. There, you can see the location of the roof deck. From the same image, you can also find out that the other name of it is sheathing. That is why you should not get confused between the two terms because both of them are the same.

Because there will be different layers or materials placed onto the deck, strength is a must. If the decking of your roof is not strong enough, damages and some other problems may occur over time. That is why we can say that the quality and strength of the roof deck have a significant impact on the durability point.

2. What is Tongue and Groove Roof Deck?

Tongue and Groove Roof Decking: All the Facts You Must Know (3)

Roof decking comes in at least five different types. Those include the plank, step, plywood, oriented strand board (OSB), and tongue and groove boards. The last one is none other but our main topic in this article.

There are two most common features of the wooden T&G roof deck type that you can use to identify it. The first is the “tongue”, which location is on one edge of the material board, and the second is the “groove”, which is on the other side.

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In the installation, the installer will insert the “tongue” of a board to the “groove” of another board. They will repeat this action until they complete the entire decking design.

Still about the installation, before it starts, you need to make sure that the T&G boards get a special finish that will make it more resistant to several weather-related conditions. It will enhance the strength and durability of the material even better.

As we already mentioned earlier, the material of this roof deck type comes in the form of a board or plank. The material used is commonly solid wood. It can hold the weight of any other roofing materials placed on the decking. Besides, it also creates a beautiful natural look, particularly for houses with no ceiling.

3. The Use of Tongue and Groove Roof Deck

Tongue and Groove Roof Decking: All the Facts You Must Know (4)

As told previously, the most common use of wooden tongue and groove roof deck type is in residential buildings. It looks even better to use for houses that do not come with any ceiling. The good thing is it is suitable to use not only in the exterior but also the interior part of your house.

The distinctive wood look of this roof deck type creates a unique appearance that you can see from beneath the roof. It even works better in specific styles, including farmhouse and rustic.

We already told you that other than this type, there is also plywood that people use quite often as the deck material in residential building roofing. The tongue and groove choice is more expensive in this case because of the solid wood material used. Although so, it offers better strength than plywood so that the higher cost is something worth it for you to pay.

One thing that you should not forget is that the price is also relative. It usually depends on the species of wood chosen. A different selection often results in a different appearance, too, no matter whether you want to add a finish to it or not.

One of the examples that many people are fond of is cedarwood. This one is not only popular because of the attractiveness of the wood grain. It is also because of the excellent weather-resistant properties that it naturally has.

4. The Benefits of Solid Wood Tongue and Groove Roof Deck

From all the sub-topics that we already discussed earlier, there are at least three benefits that you can get when choosing the tongue and groove boards material for the rood decking. To make everything even clearer for you, here is the explanation of each advantage.

Strength and Durability

Other than the tongue and groove boards from solid wood, there are some other material choices that you can use for building the structure of a roof decking. In this case, plywood is another selection used quite often in residential buildings.

FYI, plywood is sometimes available also in the form of T&G. However, this material is commonly quite thin.

On the other hand, the solid wood tongue and groove boards are more beneficial because they naturally have a better level of strength. Something like this is indeed advantageous for the entire roofing design because it makes the deck able to hold any other materials placed on top of it, including the underlay and the other roof materials.

(Video) Tongue And Groove Sheathing Roof Deck Install

From this explanation, it is clear that the first benefit of the T&G board roof deck is none other but the strength. It gets even better because this advantageous point also leads to another advantage, which is durability.

With durable material, the roof decking can last longer. It can also be away from damages that can lead to other roofing problems. This way, you should not think about decking replacement at any time soon.

Natural Appearance

Another significant benefit that you can find only in the tongue and groove roof deck boards is the natural appearance that comes from the wood material. It is something that you cannot find in any other choices, including plywood. Although the different options may have a faux wood look, it will not be as natural as the original solid wood appearance.

Installation Process Time Saver

The T&G design of the boards is another benefit that you must know. It is a detail that can save time in the installation process.

Do you know what it means? It means, if you want to build the deck on your own because you have the building skill, you can get the project done faster because of the tongue and groove boars styling.

If you decide to hire builders to do the project, it is still beneficial. The reason is that the T&G design makes the installation process done quickly so you can be sure that the service cost will not be over budget too.

5. Design Ideas

Now that you already know about all the facts related to roof decking from the tongue and groove category, especially the one from wood, it is the time to get inspired. Below, you will find at least ten ideas on how people from many places in the world include the material in their home design.

Pine Tongue and Groove Deck in a Rustic Porch Design

Tongue and Groove Roof Decking: All the Facts You Must Know (5)

The first picture that you see here is a partial covering for a deck. The area is rather large, and the homeowners want to partially cover it so they can get extra space for spending time outside without having to deal with some weather factors, such as sunlight and heat.

As you can see, the covering has an exposed roof decking. FYI, the material used here is the same as the timber choice, which is pine. This selection is simply fantastic because it creates a complementary look to the existing timber material of the deck.

This idea seems to proof that coloring is not always necessary in roof decking design like this. However, it would be beneficial to add a protective finish to it to lengthen the strength and durability.

Douglas Fir Tongue and Groove Deck in an Eclectic Living Room

Tongue and Groove Roof Decking: All the Facts You Must Know (6)

As we already told you earlier, the T&G roof decking is a thing that you can include not only in home exterior design but also in the interior. The image that you see here is the proof.

It is a photo of an eclectic living room that feels so open so that plenty of natural light can get in there easily. As you can see, the design of this place does not include any ceiling. Instead, there is a roof decking.


The material chosen by the designer here is Douglas fir. It is a species which origin is from eastern Asia and North America. It belongs to the category of timber trees and has a strong characteristic. That is why people use it a lot in constructions, including for creating the T&G material for roof decking.

Pre-finished Pine Tongue and Groove Roof Deck in a Rustic Entry Interior with Loft

Tongue and Groove Roof Decking: All the Facts You Must Know (7)

Here is another fantastic example that we want you to take a look at. It is the picture of the interior of a rustic entry, which also seems to have a loft at the upper part.

Here, the type of wood chosen for the T&G roof decking is pre-finished pine. A material like this is an excellent choice because you can directly use it without sanding and finishing first. All those procedures have been done in the factory, and that is why the name is pre-finished wood.

Another stunning inspiration that you can see from this idea is that the use of the material is not only on the roof decking. You can see clearly in the picture that it also appears on the wall even is the style is not T&G, but half log. An idea like this is the best to create a coordinating look in your home interior design.

Screened Porch with T&G Roof Decking

Tongue and Groove Roof Decking: All the Facts You Must Know (8)

T&G roof decking is also a suitable choice to use in the screened porch area. In the picture above, this element gives a significant compatibility value to the rustic style.

The wood material of the roof decking looks somewhat the same with the timber used as the frames of the screened porch. Unfortunately, we cannot find any further information about the species.

Whitewashed T&G Roof Decking in a Traditional Sunroom

Tongue and Groove Roof Decking: All the Facts You Must Know (9)

If you ask about whether or not we can add color to the wooden T&G roof decking, the answer is yes. This home element does not always come in an uncolored or unstained appearance.

As an example, you can see the roof decking in the picture of a traditional sunroom above. Here, this element gets a whitewash to add a subtle white color to it.

The final look does not only affect the appearance of the wooden T&G material. It also affects the whole space and makes it gains an airy and light feel so that it becomes a more comfortable place that the homeowners can use to spend time.

Besides, you can also see the choice of the black and grey furniture set lying in there. The whitewashed roof deck seems to create a balance so that the sunroom does not feel too dark and gloomy.

Cedar T&G Roof Decking in a Pool House

Tongue and Groove Roof Decking: All the Facts You Must Know (10)

The picture that you see here is the interior of a residential pool house. As you can see, the place has the domination of wood materials, including the T&G roof deck, which is from a red cedar.

Another wooden material in this pool house interior appears on the walls with the combination of cedar paneling and beadboard paneling for the wainscot. On the floor, the material used is laminate.

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Overall, all the wooden material used in the design creates a warm atmosphere. It also looks cozy with a woody appearance that is not dark at all. Plus, there are also some additions of white tone that brightens up the room, including from the beadboard material, the windows, and the doors.

White T&G Roof Decking in a Solid Patio Cover

Tongue and Groove Roof Decking: All the Facts You Must Know (11)

If you want to create a solid patio cover, you can also include the T&G roof decking as a part of it. A detail like this can enhance the structure style value as well as adding a natural touch to it.

As an example, you can take a look at the picture above. The solid patio cover here is rather large and tall.

It has T&G decking as the detail of the room. The design is quite interesting because there are open parts right in the center of the solid cover that allows some natural light to brighten up the patio area under it.

Wooden T&G Roof Decking in a Gazebo Design

Tongue and Groove Roof Decking: All the Facts You Must Know (12)

Another idea that you can see in this picture is the use of T&G roof decking in a gazebo design. At a glance, you can see that the type of wood used for this element is not the same as the worn-out timber material of the structure. However, you can see how both of them complement each other nicely.

The T&G roof deck color even looks nice being paired with the bricks of the fireplace and pavers of the flooring under it. Together, they create not only a cozy place to hang out outside the house but also a space with a natural touch to enjoy.

Red Cedar T&G Roof Decking in an Outdoor Kitchen and Pavilion

Tongue and Groove Roof Decking: All the Facts You Must Know (13)

This next image contains the next idea that we would like you to see and get inspired. In the picture, you can see a pavilion that at the same time, also functions as an alternative outdoor kitchen, dining, and living area all at once.

All the wooden materials used here, including also the one used for the T&G roof decking, is from cedarwood. That is why the coordinating look from this pavilion design simply looks fantastic.

It gets even more exciting because material like this is commonly sturdy. It means you can count on it as a form of home investment to create a pavilion that can boost the quality of the outdoor living of your house.

Cedar T&G Roof Decking in an Outdoor Living Room Design

Tongue and Groove Roof Decking: All the Facts You Must Know (14)

In this last idea, you can see the use of cedar T&G roof decking in a pavilion too. However, the design is quite different in the way that the function is only for an alternative outdoor living room.

In the design, there is a built-in lighting system included. It makes the roof decking more visible, especially at night.

Although the size of the pavilion is not too big, the addition of the T&G roof decking here makes everything looks better. The textured look even creates a better aesthetic in the outdoor living room.

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6. Closing

Those are all the facts that we can share with you about the tongue and groove roof decking. One thing that you need to remember is that this home element comes in various material options.

However, in this post, we want to focus more on wooden selection. That is why, in the part where we tell you about the benefits, all the values tend to point out to the wood T&G roof decking instead of the others.

Hopefully, you will find all the information we share in this article beneficial. If there are some points that we miss, please do share your thought.


What wood is best for roof decking? ›

Oriented strand board (OSB) – OSB is the most common type of material used for roof decking. It's durable and readily available, and has relatively low costs. OSB is made of interwoven strands of wood bonded with adhesive.

How do you install tongue and groove roofing decking? ›

Tongue and Groove Installation on a Timber Frame Home - YouTube

Can you use tongue and groove for decking? ›

The tongue and groove board design makes it ideal for many applications and it is particularly popular in the porch flooring industry. It can be used for decking but is often reserved for covered porches and small outdoor patios.

What is the maximum span for 3 in tongue and groove decking? ›

Three Inch Decking

Not more than 10% to be less than 10 ft. Not more than 1% to be 4 to 5 ft.

How thick should roof decking be? ›

The typical thickness of roof sheathing is about 7/16-inch, which is just under 1/2-inch.

How far can tongue and groove decking span? ›

Fastening: At each support, two-inch decking shall be toenailed through the tongue and face nailed with one nail using 16d common nails. Span: Our Fir & Larch Select Struc can easily span 7' between supports. Reach out to us and explain your application if you're trying to achieve a further span.

How do you insulate a tongue and groove roof? ›

Install a vapor barrier on the backside of the tongue and groove. Apply open-cell foam three inches thick from stud to stud. Alternately, use closed-cell spray foam applied one-inch thick; it acts as its own vapor barrier. Fill to the top of joists with blow-in cellulose material.

Can tongue and groove be used for roof sheathing? ›

Tongue & Groove Boards

T&G roof decking, however, looks classy and rich. In fact, T&G boards are most frequently used when the sheathing is visible from the inside such as in cathedral ceilings or in some cabin-style homes, especially if the span of the rafters is greater than 2 feet.

Is tongue and groove decking waterproof? ›

The 1-inch-thick tongue-and-groove deck boards are solid PVC with no fillers and an ASA cap. What keeps the water out is the decking's Super Seal, a unique vulcanized silicone gasket that wraps around the tongue and is held in place via keyways (see illustration, below).

How much does tongue and groove cost? ›

Tongue and groove typically costs between $1.25 — $1.60 per linear foot, or around $2.50 to $3.00 per square foot. Some wood species, like cedar, will cost you way more than yellow pine or spruce.

How do I waterproof my upper deck? ›

Installing a deck drainage system during construction is the best way to waterproof under your entire deck. A deck drainage system diverts water away from the joists and beams. An over-the-joist deck drainage system such as Trex RainEscape provides 100% protection from the damage caused by wood repeatedly getting wet.

How far can a 2x10 span for a roof? ›

Max. Live Load 20 lbs/ft2 (956 N/m2)
Maximum Span (ft - in)
Nominal Size (inches)Rafter Spacing, Center to Center, OC (inches)Lumber Grade
2 x 101227' - 6''
2420' - 9''
10 more rows

How far can a 4X12 span without support? ›

Dimensional Lumber Deck Beam Span Chart
Joist Spans
Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine4X108'-4"
17 more rows

How many beams should a deck have? ›

For a deck that is 15 feet wide with 2×10 joists spaced at 16 inches apart, you have two options. You can use two beams, one at 7.5 feet and one at 15 feet, to provide support.


1. A-Frame Cabin: Building a Tongue & Groove Roof
(Ozark Mountain Cabin)
2. How to insulate a roof with no attic.
(The Dean)
3. Running 3x6 Laminated Roof Decking
(Southern Wood Specialties)
4. Roof decking H clip what is an H clip and why they are so important! + Time laps and drone montage
(Grand Roofing Inc.)
5. How to install Trex composite decking
(Perkins Builder Brothers)
(mac plastering)

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