When you're dreaming up that perfect backyard deck, the vision often starts with the finished product – the smooth composite boards, the comfortable seating, the gentle sway of a hammock. But before any of that can happen, there's the foundational work, and for many DIYers, that means deck blocks. These sturdy concrete supports are a popular choice, especially for floating decks, because they simplify the process and can be quite cost-effective. However, getting the spacing right is absolutely crucial for a safe and stable deck.
So, how do you figure out where to place these blocks? It’s not just a matter of eyeballing it. The spacing of your deck blocks directly impacts how well your deck can handle weight and resist movement. Think of it like this: if you spread your support points too far apart, the deck boards and joists can sag or even break under pressure. Too close, and you might be over-engineering it, using more blocks than necessary, which can also add to costs and complexity.
While there isn't a single, universal "deck blocking spacing chart" that fits every single deck design, the principles are consistent. The key factors influencing spacing are the type of lumber you're using for your joists, the size of those joists (their depth and width), and the expected load the deck will carry. Residential decks typically need to support a combination of live loads (people, furniture) and dead loads (the weight of the deck itself).
Generally, for standard lumber sizes like 2x6 or 2x8 joists, you'll find that spacing them about 16 inches on center is common. This means the distance from the center of one joist to the center of the next is 16 inches. The deck blocks then need to be positioned to support these joists at appropriate intervals. For a floating deck, the blocks are usually placed directly beneath the joists, often at the ends and at intervals along the length of the joist.
For a 16-inch on-center joist layout, you might find yourself placing deck blocks every 4 to 6 feet along the length of the joist, depending on the span and the lumber's strength. Longer spans will require closer block spacing. It’s also important to consider the perimeter of your deck. The outer joists will need support too, and their placement will dictate where blocks are needed along the edges.
What I've noticed from looking at various guides and discussions is that many DIYers find themselves searching for a "deck block spacing calculator" or a "floating deck framing calculator." These tools are incredibly helpful because they take the guesswork out of it. They often ask for your joist size, span, and desired on-center spacing, and then they'll suggest the optimal block placement and even estimate how many blocks you'll need.
When you're planning, it's always a good idea to consult local building codes, as they often have specific requirements for deck construction, including footing and support spacing. Even for a floating deck that doesn't require deep footings, safety and stability are paramount. You want a deck that feels solid underfoot, not one that bounces or creaks alarmingly.
Ultimately, building a deck with blocks is about understanding the load-bearing principles. It’s about ensuring that the weight of your deck and everything on it is distributed evenly across your supports. Taking a little extra time to research spacing, perhaps using an online calculator or consulting a deck-building guide, will save you a lot of potential headaches down the road and ensure your deck is a safe, enjoyable space for years to come.
