Building A Deck? The Costs and 9 Tips You Need To Know

Should Building A Deck Be a DIY Project?

Adding a deck to your house can be a great way of increasing your living space. Not only does it get you outside and in the fresh air, but a deck can also give you a fun space for gathering and entertaining guests.

While it’s far less expensive and easier to install than other alternatives (such as adding an addition to your home), the cost to build a deck is anything but cheap. At least half of the cost will be for the materials you’ll need to build it. The remaining bulk of the expense will be on the labor required for its construction.

Let’s break down:

hire someone to build a deck or do it yourself?
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What It Costs to Build a Deck

Decking Materials

The type of materials you choose to use for building your deck will have a big impact on the overall cost of the project. This will include everything for both the interior and exterior of the structure, including the framework, decking boards, railings, stairs, hardware, and many other components. 

For example, if we assume you’re building a 16-foot by 20-foot deck resulting in an area of 320 square feet (sqft), then the overall average price you could expect to pay would be as follows:

  • Pressure-Treated Wood = $4,800-$6,500 ($15-$20 per square foot)
  • Plastics & Composite Decks = $9,600-$12,800 ($30-$40 per square foot)

While the grand majority of most deck frameworks are made with pressure-treated wood, the outside exterior can be any variety of wood or material choices. Depending on which one you decide to go with, this could dramatically raise or lower the overall cost of the project. 

For example, going with wood is the cheapest option. But it will require regular maintenance like staining and even replacing after a few years due to wear and tear. By comparison, you could choose to go with materials like composite or aluminum which will require almost no maintenance at all since they will last much longer than wood. However, they will also be far more expensive.

Here are some of the typical costs of various decking board materials per square foot:

Material$/sq. ft Low end$/sq. ft High End
Pressure Treated Wood$2$5

It is also worth considering that contractors are going to have access to materials at a cheaper rate, probably as much as 15%, than you are going to be able to find.


Labor can constitute a significant portion of the overall deck building expense. But surprisingly, there may be some worthwhile tradeoffs between outsourcing this project to the professional versus tackling it yourself.

For example, logically you may assume that you’ll save a boat-load of money if you can do all of the work on your own or with a friend. Exploring this idea further, let’s reasonably estimate that it will take you anywhere from three to four weekends to build a 320 sqft deck from start to finish. You will also most likely require a helper since many of the boards will be too heavy or long to lift yourself.

Since the average median income in the U.S. of $63,179, we can say that the value of you and your assistant’s time is approximately $30 per hour per person. Therefore, we can calculate the range of the total labor expense to be anywhere from $2,400 to $7,200.

By contrast, if you were to hire this job out, then you would most likely expect to spend an average of $7,000 for labor. Not only could this potentially be cheaper than building it yourself, but because the crew is experienced and likely to have more people than just two, the entire project could also most likely be completed in as little as two days.


The need for permits will vary from location to location. If you do require a permit, they will generally be less than $100. However, the cost in some areas could be as high as $500.

Tips for Building a Deck

Whether you decide to build the deck yourself or hire a crew, there will be a few things you’ll want to know ahead of time to keep your project on schedule, safe for both your house and deck, and under budget.

  1. Check the local laws and get permits
  2. Get your deck designed for free
  3. Make sure the foundation is solid
  4. Keep the slope under the deck away from the house
  5. Make sure joists are covered
  6. Keep adequate space between deck boards
  7. Use under-mounted deck fasteners
  8. Choose the material that suits your budget and where you live
  9. Be selective with landscaping

Check the Local Laws and Get Permits

Nothing can derail and delay your project like a city inspector showing up and shutting you down due to paperwork. To avoid this situation altogether, do a little homework ahead of time and check up on the local requirements for permits. If one is necessary, apply for it well in advance of starting your project.

Get Your Deck Designed for Free

While some deck building professionals will try to up-sell you on the notion that they have specialized knowledge about designing a deck, the reality is that there are many free services you can use to do this for you. 

For example, many big-box home improvements stores will offer you this service if you plan on buying all of the materials you need through them. This can be a fairly straight-forward way to get this done, especially if all you’re looking for is just a basic rectangular shape.

Make Sure the Foundation is Solid

When someone tells you that the posts for your deck foundation need to be well below the frost line of the ground, it’s best to take this seriously! Water has a way of making things shift, and you don’t want your structure to be uneven or unsafe from frost heave. It is typically recommended to go four to five feet below the ground to establish your base. This will ensure that you are not at risk of heaving.

What is frost heave?

Frost heave is the act of the ground shifting, due to the formation of ice in the soil. This can unsettle all forms of construction, and certainly your deck.

Be careful with clay soil

Clay is sensitive to the moisture level at all times, so it is not just about issues in the winter, but issues all the time. The structure of clay soil changes radically from rain to dry periods, and this will create an unsettling foundation.

Keep the Slope Away From the House

As with any landscaping around the house, a major concern for the foundation is if water is directed back towards the house. To avoid this, make sure the ground is sloping away from the house so that any water runoff doesn’t create problems.

Cover the Joists

Building a deck with protective covers over the joists
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Deck joists with protective cover

Deck joints lay flat underneath the deck and because of that they can have water sit on them in they are not covered. If water is left to sit on the wood this can degrade the wood structurally, which becomes a major problem.

Keep in mind what you are covering them with as the color likely shows through the cracks in the deck.

Leave an Adequate Gap Between Deck Boards

An adequate gap is necessary between the deck boards to prevent debris from building up in the gaps and then holding moisture which can damage the wood. While people sometimes opt for the aesthetics of the boards being very tight, this can create problems for the wood.

Use Under-Mounted Deck Fasteners

Building a deck with under-mounted fasteners
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Under-mounted fasteners

Under-mounted deck fasteners provide a cleaner look on your deck by preventing the appearance of screws. Additionally, when you have screws on your deck you open up the risk of screwing too deep into the wood and leaving space for water to sit on top of the screw and rot the surrounding wood.

Choose the Material That’s Right for You

Again, the type of exterior decking material you choose will be important. Not only can it affect the price of the project, but it could also mean signing up for future maintenance and labor such as staining the deck or eventually replacing the boards. Depending on how long you plan to live at your house, you’ll want to consider your capacities.

Be Selective About the Landscaping

After you get done building your deck, it will be very tempting to want to decorate the perimeter with beautiful landscaping such as flowering shrubs or ornamental trees. However, these plants should be chosen with caution. Some tree and shrub roots can grow very large, and if they come into contact with a deck post, it could compromise your foundation. Therefore, it’s best to keep the landscaping to a minimum.


Unless you liken yourself to Mike Holmes, any potential financial savings may not be worth it compared to the time to complete and chance for problems. We tend to see this as a DIFM job.

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