Wondering how much it actually costs to build a rooftop deck in Seattle? Worried about being blindsided by unexpected costs during the rooftop deck installation?
Most homeowners are surprised by what actually drives up the price—and what they can control.
At RoofSmart, we avoid these issues by identifying potential issues during roof inspections and having an in-depth conversation with customers about job costs. That way, everyone is on the same page.
We understand that rooftop decks are expensive, so our goal is to make sure that our customers know the total cost ahead of time and are prepared for potential unexpected costs.
In this article, we’ll break down the full cost range for rooftop decks in Seattle, the key factors that affect pricing, and what you need to budget for unexpected issues.
What is the average cost of a rooftop deck?
To install a rooftop deck in the Greater Seattle area will cost anywhere from $40,000 to $80,000. Rooftop decks are an efficient and fun way to make use of your rooftop space, but they require precise attention to detail and a higher level of expertise to be installed correctly.
That alone makes them an expensive feature, but keep in mind that Seattle’s high cost of living also drives up labor prices for these types of projects. In other words, Seattle prices are almost always higher than the national average. And installing a rooftop deck is usually a 2 to 4-week process because there is so much to do.
How much do different rooftop deck materials cost?
There are many factors that contribute to the cost of a rooftop deck installation, but let’s start with one of the biggest ones: choosing a rooftop deck material.
For your rooftop deck, you can decide between a few different materials. The most common options are walkable membranes, tile, or pavers. Choosing a certain material can have a drastic impact on the total cost of the project.
Here’s an overview of what each of these materials is and how much they cost to install:
Walkable Membrane
This is the lower-cost option that gives great leak protection with a luxurious feel (as an example, a popular brand is Duradek). It costs around $10 to $15 per square foot to install.
Walkable membrane rooftop decking is very similar to PVC (a flat roof material), but with some key differences. Instead of being smooth and slippery, it is textured, which makes it safe to walk on even when wet.
It also comes in a wide variety of colors and styles so that you can choose what looks best on your home.
Tiles or Pavers on Pedestals
The fancier (and much more expensive) option is to get tiles or concrete pavers and install them on pedestals. This adds some extra steps to the process, but it looks amazing.
For example, here’s a shot of the pedestals underneath some IPE wood deck tiles during installation:
Depending on your budget and aesthetic preferences, you can choose between a variety of tiles for your rooftop deck. This includes (but is not limited to):
- Stone or concrete pavers
- Rubber tiles
- Porcelain tiles
- Hardwood decking tiles
These options vary in quality, but they’ll cost between $60 to $100 per tile to install (in addition to needing pedestals, which are $45 apiece).
Remember that before you install the pedestals and tiles, you’ll still need some sort of membrane (like PVC) underneath to protect your roof from leaks and water damage.
Which factors impact the cost of installing a rooftop deck?
Many other factors can increase the cost of installing a rooftop deck. A lot of homes need extra work to make sure that they can handle the challenges of a rooftop deck.
1.) What kind of railing are you installing?
If you’re installing a deck multiple stories up, you’ll definitely need to add a railing. This will typically cost you an extra $200 to $400 per linear foot (on top of the cost of the deck) for higher-end materials like glass panels or steel cables.
A cheaper alternative is aluminum railing, which has a more traditional look and only costs about half as much as the higher-end options.
The railing is a very expensive part of any rooftop deck project because installing it is such a labor-intensive process.
The process is different depending on the type of railing you choose and what needs to be done to mount the railing:
- Types of railing: Three common railing options for rooftop decks are aluminum railings, glass panels, and steel cables.
- Glass panels are more difficult to safely transport to the rooftop, but steel cable is much more tedious and time-consuming to install. Your installer will have to make sure that it’s lined up perfectly and isn’t too tight or too loose.
- Aluminum railing is cheaper than these other options, but it’s also a higher risk for leaks because it has more entry points for water.
- Mounting the railing: If you mount your railing toward the inside of the deck, it’s easier (and a little less expensive). But, you lose space on your deck. You can maximize your deck space by mounting the railing along the outside of the deck’s perimeter, but then the installer has to set up scaffolding and do extra labor that drives up the price.
Here are some examples of different railing mount styles:
Railing that is surface-mounted on top of the deck:
Railing mounted along the outer edge:
2.) Is your property accessible?
If you have a small property with houses very close to yours, trees near the house, or if your property is on a hill, this can make it difficult for your roofer to work on the roof and get materials up there.
Having a property that is difficult to access will increase labor costs because it will take extra time to set up scaffolding or other necessary measures to work on your roof.
3.) Can your home support the weight of a rooftop deck?
Many roofs are not designed to hold a bunch of extra weight, so if you’re adding stone or concrete pavers or you want a hot tub on your rooftop deck, you’ll need to have your home re-engineered to support it.
This can easily add several thousand dollars to the cost of the project.
If you think you want to eventually add a hot tub, you should definitely get your roof reinforced while the rooftop deck is being installed. Otherwise, you’ll have to rip it all out and start over.
4.) Is your roof protected from condensation underneath the deck?
Most of the time, the answer to this question is no. If you’re converting your home to a flat roof to put the rooftop deck on top, or even if your home is a new build, waterproofing for condensation is an element that’s often overlooked.
To properly protect your home, you need to add foam insulators underneath the roof deck to protect it from condensation build-up. Without this, your roof will rot in 10 years or less.
This will cost several thousand dollars because it adds another layer of height to the roof. You might even have to raise up the doorway (which, again, will cost extra).
5.) Is your home sloped to help with drainage?
The importance of protecting your roof from leaks and water damage cannot be overstated. So, another step you should take is getting your roof sloped to help it drain more efficiently. This usually costs around $2 to $4 per foot.
What’s Next? How to Find the Right Roofer for Your Rooftop Deck
At this point, you now have a clear understanding of what drives the cost of a rooftop deck in Seattle—from materials and railing choices to structural reinforcements and accessibility challenges.
But knowing the costs is only half the battle. The truth is, your final price and experience will depend heavily on the contractor you hire. Not every roofer is qualified to handle the complexities of a rooftop deck.
That’s why your next step is crucial. Read our article “How Do I Know If A Roofing Contractor Is Qualified?” so you can avoid costly mistakes, spot red flags early, and choose a contractor who can do the job right the first time.
Or, use our Qualified Roofer Checklist to quickly and confidently evaluate your roofer options.
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