Step-by-Step Guide to Using a Decking Materials Calculator

Building a deck is an exciting project! But before you start hammering away, you need to know exactly how much timber and other materials you’ll need. Getting this right saves you money, time, and frustration. Today, I’m going to walk you through a simple, step-by-step guide to calculating decking materials. Whether you’re a builder, landscaper, or a keen DIYer, this guide will help you plan your deck perfectly.

Why Use a Decking Materials Calculator?

A decking materials calculator is a handy tool that helps you estimate the amount of timber and accessories needed for your deck. It takes the guesswork out of the process. Instead of buying too much or too little, you get just the right amount. This means less waste and fewer trips to the timber yard.

Using a decking materials calculator also helps you budget better. You can see the cost of materials upfront and avoid surprises later. Plus, it speeds up your project planning. You’ll know exactly what to order and when.

At Foxhills Timber, we provide quality timber products perfect for decking. From treated timber to sleepers and fencing materials, we’ve got you covered. Let’s dive into how you can calculate your decking materials step by step!

Close-up view of timber decking boards stacked neatly

Step 1: Measure Your Deck Area

The first step is to measure the size of your deck. You need the length and width in metres. Multiply these two numbers to get the total square metres of decking surface.

For example, if your deck is 4 metres long and 3 metres wide:

```

4m x 3m = 12 square metres

```

This is the area you will cover with decking boards.

If your deck has an irregular shape, break it down into smaller rectangles or squares. Measure each section separately, then add the areas together.

Step 2: Choose Your Decking Board Size

Decking boards come in different widths and thicknesses. Common widths are 90mm, 140mm, or 145mm. Thickness usually ranges from 19mm to 32mm.

Choosing the right board size affects how many boards you need. For example, if you pick 140mm wide boards, you can calculate how many boards fit into the width of your deck.

To find the number of boards needed along the width:

```

Deck width (mm) ÷ Board width (mm) = Number of boards

```

For a 3-metre (3000mm) wide deck with 140mm boards:

```

3000 ÷ 140 ≈ 21.4 boards

```

Round up to 22 boards to cover the width.

Step 3: Calculate the Number of Decking Boards

Now, calculate how many boards you need for the entire deck length. Multiply the number of boards across the width by the number of boards along the length.

To find the number of boards along the length:

```

Deck length (mm) ÷ Board length (mm) = Number of boards lengthwise

```

If your decking boards are 3 metres long (3000mm) and your deck length is 4 metres (4000mm), you will need to join boards or use longer boards. Usually, decking boards come in standard lengths, so you might need to buy extra to cover the length.

For simplicity, if you use 3m boards for a 4m deck length, you’ll need to buy enough boards to cover the full length, considering overlaps or joins.

Multiply the number of boards widthwise by the number of boards lengthwise to get the total number of boards.

Step 4: Add Extra for Waste and Cuts

Always add extra timber to your calculations. Cutting boards to fit corners, angles, or around obstacles creates waste. A good rule of thumb is to add 10% to 15% extra material.

For example, if you calculated 100 boards, add 10 to 15 boards extra:

```

100 boards + 15 boards = 115 boards total

```

This ensures you won’t run short halfway through your project.

Step 5: Calculate Supporting Timber and Fixings

Your deck needs more than just decking boards. You’ll also need joists, posts, and fixings like screws or nails.

Joists

Joists support the decking boards. They usually run perpendicular to the boards. The spacing between joists is typically 400mm to 600mm centres.

To calculate joists:

• Divide the deck width by the joist spacing.

• Add one extra joist for the starting edge.

  
  

For a 3m wide deck with joists spaced at 400mm:

```

3000mm ÷ 400mm = 7.5 → 8 joists + 1 = 9 joists total

```

Posts

Posts support the deck frame. The number depends on the deck size and design. Usually, posts are placed every 1.8m to 2.4m along the perimeter.

Measure the perimeter and divide by your post spacing to estimate the number of posts.

Fixings

You’ll need screws or nails designed for outdoor use. Calculate fixings based on the number of boards and joists. Typically, use two screws per board end per joist.

Step 6: Use a Decking Materials Calculator Online

If you want to save time, use a decking materials calculator online. These tools ask for your deck dimensions and board sizes, then do the math for you.

For example, you can check out this handy how to calculate decking materials guide with a calculator included. It’s quick, easy, and accurate!

Using a calculator helps avoid mistakes and gives you a shopping list to take to Foxhills Timber. We stock everything you need, from construction timber to landscaping materials, all sustainably sourced.

High angle view of a timber deck under construction with joists and boards

Tips for Ordering Timber from Foxhills Timber

• Order early: Timber can take time to prepare, especially treated wood.

• Specify treated or untreated: Treated timber lasts longer outdoors but costs a bit more.

• Ask for advice: Our team can help you pick the right timber for your project.

• Consider delivery: We deliver across the UK, saving you time and hassle.

• Check measurements twice: Always double-check your deck size before ordering.

  
  

Final Thoughts on Calculating Decking Materials

Calculating decking materials doesn’t have to be tricky. Measure carefully, choose the right board size, add extra for waste, and don’t forget the supporting timber and fixings. Use a decking materials calculator to make life easier and get your quantities spot on.

At Foxhills Timber, we’re here to help you every step of the way. Whether you’re a trade professional or a DIY enthusiast, we provide quality timber products that make your decking project a breeze.

Ready to get started? Grab your tape measure, jot down your deck size, and let’s build something great together!