Joining a decking frame securely is essential for the stability and longevity of your deck. It involves connecting the various timber components, such as rim joists, bearers, and internal joists, using appropriate methods and fasteners.
Here's a breakdown of common methods for joining different parts of a decking frame:
Joining the Frame Corners
Connecting the corners of the main frame structure is a critical first step. Based on the provided information:
- Mark and drill pilot holes before fixing.
- Use two external grade 150mm timber drive screws into each corner.
- If you are adding a fascia then you will need to countersink the screws.
This technique creates a strong, rigid corner joint for the outer perimeter of your deck frame.
Connecting Joists to the Frame
Decking joists are the timbers that the deck boards attach to. They typically connect to a ledger board (attached to the house) or a rim joist (forming the outer edge of a free-standing deck).
Common methods include:
- Joist Hangers:
- These metal connectors are the most common and recommended method for strength and ease of installation.
- Hangers cradle the end of the joist and are secured to the ledger or rim joist using specific structural nails or screws designed for hangers.
- Ensure you use the correct size and type of hanger for your joist dimensions.
- Face Nailing/Screwing:
- Driving nails or screws directly through the ledger or rim joist into the end of the joist.
- Requires careful angling (skew nailing/screwing) for better hold.
- Generally considered less strong than joist hangers, especially for structural loads.
- Toe Nailing/Screwing:
- Driving fasteners diagonally through the side of the joist into the ledger or rim joist.
- Can be tricky to do correctly and may cause the timber to split if not done carefully.
Adding Blocking and Bridging
Blocking or bridging refers to short pieces of timber installed between joists.
- Purpose: Adds lateral stability to the frame, preventing joists from twisting or bowing over time. It also helps distribute weight and stiffens the frame.
- Installation: Cut blocks to fit snugly between joists and secure them by face-nailing or screwing through the joists into the ends of the blocks.
Fasteners for Decking Frames
Choosing the right fasteners is crucial for durability, especially outdoors.
- External Grade Screws: Specifically designed for exterior use, resistant to corrosion. Timber drive screws, structural screws, and deck screws are common types.
- Galvanized or Stainless Steel Nails: Used with joist hangers (check hanger specifications) or for framing connections. Galvanized is standard, while stainless steel offers superior corrosion resistance in coastal areas.
- Pilot Holes: As mentioned for corners, drilling pilot holes before driving screws is vital, especially near the ends of boards or with dense hardwoods, to prevent splitting.
Summary of Deck Frame Joining Techniques
| Frame Component | Joining Method(s) | Recommended Fasteners | Notes |
|---|---|---|---|
| Corners | Direct fastening | External grade 150mm timber drive screws | Use pilot holes; countersink for fascia. |
| Joists to Ledger/Rim | Joist Hangers (Recommended) | Structural nails or screws for hangers | Choose correct hanger size. |
| Face Nailing/Screwing, Toe Nailing/Screwing | External grade screws, Galvanized/Stainless Nails | Less secure than hangers for structural. | |
| Blocking/Bridging | Direct fastening | External grade screws, Galvanized/Stainless Nails | Adds stability; cut blocks to fit tightly. |
By using a combination of these techniques and appropriate fasteners, you can build a strong and reliable decking frame that will support your outdoor living space for years to come.
