Building/extending a roof over a deck can either be for design or protection against adverse climate conditions.

However, a roof extension is a nice way to extend exterior space, which is common among different types of roofs.

But, a gable roof is quite different from other roofs, so how can you extend it, or is it possible to?

You can extend a gable roof over the deck using quality supports because of the length (two feet or more). However, if you are extending a smaller length, you can easily add to the roof without tempering the roof. But longer lengths will involve removing some portion of the roof to do the extension.

Ready for a Roofing Quiz?

Can You Extend a Gable Roof over Deck?

Extending Gable Roof Over Deck

Yes, you can extend a Gable roof over the deck with the right procedures and construction/roofing experience.

However, extending the gable roof over the deck is ideal during construction. However, adding strong extra supports can still extend an existing deck structure.

On the other hand, extending a Gable roof or adding a roof over an existing deck, in general, can be bad.

So it’s best to extend the roof when building the roof, initially building the gable roof, to eliminate any possible problems.

However, a gable roof extension can also be a roof overhang, but there are differences.

Normally, roof overhangs don’t extend beyond two feet, or you ruin your house/roof structure. So, extra support should be for a roof extension that’s commonly more than two feet.

Houses, mostly in tropical or rainy climates, have an extension of their Gable roof over deck.

And as a result, Gable extension on houses in such climate areas will no doubt have a longer extension.

While dry climates will have shorter extensions or none, gable roof extensions serve other purposes besides weather protection.

It adds to the aesthetics of the building.The cost is quite expensive.
It creates protection against harsh weather.It requires digging new footings which affect the original house structure.
It adds or extends living space to the house.It requires the help of an expert to construct.

How Much Does It Cost to Extend a Roof Over a Deck?

The cost of extending a roof over a deck will range from $2,000 and above. Also, if you have experience with roofing constructions, then it might cost less.

But when employing the service of a construction company or expert, some factors will affect the cost.

Considering the cost of extending a roof over a deck, some may cost more and others less.

In order words, if your roofing materials are expensive, with more complex expertise in labor, your cost will be expensive.

Also, the design and the size of the roof are factors that affect the cost. There are different roof styles, including Gable, sheds, hip roof, e.t.c., with different designs.

However, a Gable roof is one of the easiest or less complex roof extension designs. But other designs like the sheds, one of the fitting deck roofs, can be quite complex.

How Do You Extend the Roof on a Gable End?

You can extend the roof on a gable end by adding another to an existing one.

However, when the length is more than two feet, you will have to remove parts of the roof to attach trusses and other materials.

Removing part of the roof will allow you to extend the roof by attaching beams, posts, or rafters to the existing roof.

Before installing any roof extension, it’s ideal to have a preference picture in your mind.

Having a picture of what you want will make things easy if you plan on meeting with a construction company.

Also, if you are a DIY (Do It Yourself) person, seek the advice of an expert; it also helps when planning.

Extending the roof depends on how you will frame the new roof with the existing one.

To frame the roof, you use trusses or rafters to attach to the beam; the framing material should fit the beam.

Now let’s look at how to extend your existing roof of a gable end.

#1. Planning

Before doing anything construction, planning is essential. For example, extending your roof end isn’t easy or normal work but a serious construction project.

And as such, most places require a local permit before attempting such big projects, so ensure to check and obtain a permit.

Another important aspect of the planning is to get your roofing materials ready for use. For example, you should have a strong ladder, roofing cement(depends on the roof), wood, e.t.c.

And your working materials like; a nail gun, safety wear, gloves, nails, e.t.c, also you should have a complete and correct measurement of both roofs.

#2. Extend the Roof

After ensuring that all the materials are set, start the extension. The goal is to place the extension on the gable end.

Follow the guidelines below to help you do the extension right.

  • Remove some parts of the existing roofs; you will need to remove the sheathing material and fascial board. Removing the sheathing depends on the length of the rafter, so the longer the rafter, the more sheathing to remove.
  • You will have to attach the trusses and rafters to the existing roof to extend the roof. However, the support you will use at the end of the wall (a cantilever) depends on the roofing material type.
  • Then you nail and attach the rafters and beams at necessary points until the roof structure is okay.
  • After attaching the rafters, the structure is okay; now, you have to cover up the structure to align with the existing roof. At this point, you can attach the tar paper, and roofing felt to protect the roof.

Lastly, it’s important to remember that these construction jobs can be dangerous, especially when you are a novice.

For instance, taking on the job is unsafe when you have a tall building or a story building. Thus it would be best if you had a roofer/expert assist you when using the ladder to avoid accidents.

The builders/roofers will consider the climate of a particular area before making any change; for instance, climate determines the length.

Also, it’s of utmost importance that you get an expert for your extension job. An expert will know what’s best and do more to make the roof extension successful.

How Do You Connect Two Gable Roofs? 

To connect two Gable roofs, you must ensure that the ridge of both roofs crosses and meets at the same point/height.

The ridge is a horizontal framing for addition that has to intersect correctly to connect the roofs.

Also, it would help if you had roof support, the rafter. You will nail the rafter ends to the ridge board if there is a ridge board.

In addition, use beams to add extra support to the roof, as the rafters may not be enough. And finally, make sure you install the right protection as it’s essential.

How Do You Tie an Addition to an Existing Roof?

Tying an addition to an existing roof depends on the type and style of roof present.

However, the different roof styles will, in the same way, try to connect the rafters of the addition to the frame system of the existing roof.

And make sure one roof doesn’t weigh more than the other. So depending on what roof style the roofs are, set the rafter and trusses for support.

And you will use a valley board to help you nail the roofs together and the rafters and trusses together to ensure correct sealing.

Also important, if your roof requires removing part of the roof to attach the new roof, do it carefully.

Note that tying an addition to an existing roof requires more than one or two persons to do it. And it would be best if you remembered your safety wears.


A Gable roof is best for removing water, as the sloping design doesn’t encourage water buildup. Building a roof over your deck is worth considering, regardless of the installation expenses.

Also, a roof deck will add value to your house, aside from the beauty and protection it gives.

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