So you want to build a curved deck huh? There are several different methods but most of them are expensive and involve a professional unless you have the time and patience to learn yourself. In this post we will show you how to build a curved deck for under $200 in materials.
Curved deck frames require extra framing and support compared to a straight deck frame, but curved decks add an elegant look to any house. If you are building a curved deck, it is much easier the less curves there are in the design. For example, if there is only one curve, all of the diagonal measurements will be the same, which makes it easy to know where each joist is located on the frame. If there are multiple curves, then all of the joists will not be equal distances apart and that makes it more difficult to get your framing balanced.
🛠 What This Is About
✅ Curved composite decking lets you create something unique.
✅ It can be used as standalone circular decks, curved steps, deck walkways, or seating zones.
🧱 How It Works
Your original:
Curved composite decking offers a chance to create a truly unique outdoor space and it can be used in myriad ways. Here are just a few of our favourites which will hopefully inspire you…
An eye‑catching standalone circular deck in the centre of your garden.
Curved decked steps leading from your home to your outside space.
A curved deck surrounding a pond or raised area.
A curved composite decked walkway meandering through your garden.
A raised curved bench around a curved deck area on which to relax and enjoy your garden.
Plus additional details verbatim from web:
Despite the seemingly rigid nature of composite wood, you can use composite deck boards and fascia to create a variety of beautifully curved designs.
Composite fascia boards are thin and flexible enough that they will bend around the curve to give the edge a clean finish. … Gently bend the fascia board around the curve, screwing it into the ends of the joists using a standard countersunk wood screw.
📋 Materials or Tools Needed
- Composite decking boards (brands vary).
- Composite fascia boards (thin & flexible).
- Joists spaced approx 450 mm apart.
- Bracing infill pieces cut at angles to follow curves.
- Screws (stainless‑steel or galvanised) every ~200 mm on fascia.
⚙ Step‑by‑Step Instructions
- 🧱 Lay joists to form curve, max 450 mm spacing.
- 🔪 Cut joists to curve shape using circular saw.
- 🧱 Infill bracing pieces between joists, with angled ends to match curve.
- 🧩 Install decking boards per manufacturer’s instructions.
- 🚪 Add curved fascia board: gently bend it to match the curve, then pre‑drill and screw across joists.
- 🌡 For tighter curves, heating may be used—but it’s risky.
✅ Pros and Cons
| ✅ Pros | ⚠️ Cons |
|---|---|
| Unique, stylish curves soften straight edges. | Harder to build than straight deck. |
| Flexibility in odd‑shaped or limited outdoor spaces. | Needs tighter joist spacing. |
| Composite fascia bends around curves for a clean edge. |
💡 Common Mistakes to Avoid
- Spacing joists too far apart (mustn’t exceed ~450 mm).
- Skipping angled bracing between joists.
- Over‑bending fascia boards or heating too much.
- Not pre‑drilling screws in fascia every 200 mm.
👷 Who Should Use This
- Homeowners or pros wanting a stylish garden focal point.
- Spaces with curved edges, ponds, walkways, or benches.
- Anyone looking to soften rigid back‑yard architecture.
📌 Quick Facts
- Joist spacing: ≤ 450 mm.
- Fascia screw spacing: every ~200 mm; leave 5 mm end gap.
- Fascia board must be flexible thin composite.
- Heating optional—but tricky and not always worth it.
📊 Visual Table: Subframe vs Deck Finish
| Stage | What You Do | Why It Matters |
|---|---|---|
| Subframe | Lay joists & bracing curved to shape | Keeps fascia and deck stable |
| Deck boards | Fix per normal instructions | Maintains manufacturer warranty |
| Fascia | Bend & screw along curve | Gives clean, continuous edge |
🧰 Expert Tips
- Use a radius arm or trammel to mark smooth curves on joists.
- Tape joists or use joist tape to prevent moisture damage.
- Practice heating on scrap boards before bending real fascia.
🔍 Compared with Similar Methods or Products
- Straight composite decking: Easier, cheaper, but less striking.
- Wood decks: Traditional look but warps, splinters, needs upkeep.
- Circular patios (stone, pavers): Softer shapes; harder underfoot, not warm barefoot.
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The process involved in building a curved deck
| Item | Details |
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| Curved Decks Advantages |
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| Materials Used |
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| Building Considerations |
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| Designing the Deck |
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| Construction Steps |
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| Tools Required |
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![How to Build a Deck: Step by Step Guide [with Pictures]](https://plasticinehouse.com/wp-content/uploads/2018/05/Curved-deck-from-top.jpg)
How to Build Curved Deck Stairs
Building curved deck stairs is no different than building straight ones, except that instead of using pressure-treated 2x4s, you’ll use 2x6s — or even 2x8s if you want to make them extra-strong. The same goes for the rails and stringers: Make sure they’re made from pressure-treated lumber or cedar.
As with any deck project, it pays to take your time when building a curved deck frame. You’ll want to measure twice before cutting once; check every measurement twice; and make sure everything fits together perfectly before driving any nails or screws into place.
In this video, we’ll demonstrate how to build a curved deck frame using pre-made parts.
A curved deck frame is an excellent way to add elegance and character to your outdoor living space. It can also be used as an accent feature in a corner or along the edge of your deck.
To build this type of frame, you will need the following materials:
2×4 lumber or 2×6 lumber – cut down into 2′ lengths (1 piece will be used for every step)
2×12 lumber – cut down into 6′ lengths (1 piece will be used on each side of every step)
Is it necessary to utilise curved composite decking?
The decision to construct a curved deck for your outdoor space might be made for a few different reasons. Initially, the design. Introducing a trendy and eye-catching focal point for your garden may be accomplished by introducing a curving decking area, which allows you to break away from standard designs. In contrast to the straight lines that are characteristic of conventional decks, curved designs have the ability to reduce the visual effect and blend in seamlessly with the scenery that is surrounding them.
Space comes in second. You can have a restricted amount of space or an outside area that is shaped in a unique way. If this is the case, a curved decking provides a great deal more flexibility, allowing you to make greater use of the area that is available to you while yet maintaining its gorgeous appearance.
A guide on constructing a subframe for curved decking
Put the joists in place.
This is the first step in the process of laying the joists for your substructure. In order to ensure that the fascia is held in place within the curve, it is recommended that you measure the inside curve of your new deck and make sure that your joists are positioned at regular enough intervals. These should be spaced no more than 450 millimetres apart.
- Remove the curve from the curve
From this point on, you can use a circular saw to cut the joists into the proper curved shape. - Brace yourself
Last but not least, you will need to use a substance known as “bracing” to fill in the spaces between the joists. This will provide the fascia board with a sturdy foundation to which it can be attached. Always keep in mind that the ends of the infills should be cut at an angle in order to follow the curvature. Composite deck with a curved shape in a garden
Installation instructions for curved composite decking
Installing the system
You are now able to install your composite decking boards, which you should do while keeping in mind the directions provided by the manufacturer. - Construct the curve and
A curve can be cut into your deck boards by using a circular saw. This curve should be cut in the same direction as the curve that you have made in the subframe. Third, install a fascia board.
After that, you will need to install a fascia board that is appropriate in order to make a smooth outer curve.
How to Build a Curved Deck Frame
A curved deck frame is an attractive way to add architectural interest to your outdoor living space. A curved deck frame can also be used where a straight deck rail would not fit. Whether you want to build a curved deck frame around a hot tub, or just want to add a unique touch to your deck, you can build one using common tools and materials.
When building a curved deck frame, it is important to use the right lumber. The lumber needs to be strong enough so it will not sag under the weight of the people who will be using it. It also needs to be able to withstand weather conditions such as rain or snow without rotting or warping. The best choice for this type of project is cedar lumber because it has natural resistance against rot and deterioration from moisture. Cedar does not need any type of finish because it has an attractive reddish brown color that does not need to be stained or painted.
The first step in building a curved deck frame is measuring the length and width of your desired shape with string and then marking these measurements on your lumber with chalk lines so you can cut them out with power saws or circular saws. Next use two-by-four plan
Building a curved deck is not that different than building a straight one. You just need to be more careful about your measurements and design. Here are some tips for building your curved deck:
1. Make sure you have enough room for the radius you want. A deck with a radius of 6 feet can be built in an area as small as 20 feet by 10 feet, but if you want a larger radius, you may need to consider moving back from the house or adding more space behind the house.
2. Measure the distance between the center post and end posts at each section of the curve before cutting them down to size. This will ensure that when they’re all connected together they make up the correct shape and size.
3. Use flexible polyethylene pipe as a form around which concrete can be poured for support posts or footings. The pipe is cheap, easy to use and allows you to pour concrete around it without having to worry about it falling over or getting damaged during construction. When finished pouring, simply remove it from the hole using pliers or tongs and proceed with other steps in your project plan
A curved deck is a beautiful sight to behold. It can add to the overall aesthetic of your home and give you a unique space for entertaining or relaxing. A curved deck is also an economical way to increase the size of your deck without having to build any additional structure.
The first step in building a curved deck is determining whether it’s structurally possible. If you already have a deck, simply measure the distance between the posts. If this distance is less than 12 feet, you can use pressure-treated lumber for framing. For longer distances, you will need to use cedar or redwood because they are more resistant to moisture damage than pressure treated wood.
Once you’ve determined which type of lumber to use, cut out all of your pieces using a circular saw. Make sure that each piece is exactly 45 degrees with respect to its neighbor on either side. This can be done by using a protractor or simply placing two sticks together at an angle and marking where each piece should be cut on both sides so that they meet in the middle when put together properly (see pictures).