How to Frame a Deck (Ledger, Beam, and Joists)
Learn to properly frame a residential ground-level or raised deck by installing the ledger board, erecting the support beam, and setting crowned joists.
- Read the tools, materials, safety notes, and steps below for free.
- Tap Start Camera Coach when you want hands-free voice help.
- Allow camera and microphone. Point your phone at the work; the coach watches your progress and tells you the next step.
🧰 Required Tools & Equipment
- ✓ Circular saw
- ✓ Impact driver
- ✓ 4-foot spirit level
- ✓ Speed square
- ✓ Tape measure
- ✓ Chalk line
- ✓ Palm nailer or hammer
📦 Materials & Supplies
- ✓ Pressure-treated framing lumber (2x8 or 2x10)
- ✓ Structural ledger screws
- ✓ Z-flashing and deck flashing tape
- ✓ Post-to-beam connectors
- ✓ Metal joist hangers
- ✓ 1-1/2 inch structural hanger nails
⚠️ Safety Checkpoints & Warnings
- • Ensure the house rim joist is sound before fastening the ledger; never attach a ledger over vinyl/aluminum siding.
- • Wear safety glasses and hearing protection when operating the circular saw and driving structural fasteners.
- • Temporarily brace all upright posts and drop beams before removing hands or placing loads.
- • Use only code-approved exterior-grade structural fasteners (never drywall screws or standard zinc screws).
📋 Step-by-Step Guide (6 Steps)
Mount and Flash the Ledger Board
Position the pressure-treated ledger board against the house rim joist at the calculated height below the indoor threshold. Fasten it using staggered structural screws driven into every joist bay according to code spacing. Install metal Z-flashing over the top edge and seal the joint with adhesive flashing tape.
- • Ledger board is perfectly level against the sheathing.
- • Structural screws are driven in a distinct zigzag pattern.
- • Z-flashing rests tight over the top edge with flashing tape covering the upper lip.
- • Fastening the ledger directly on top of house siding rather than against the solid rim joist.
- • Placing ledger screws in a single straight line along the grain, risking splitting.
Set Posts and Support Beam
Plumb support posts on concrete footings and secure them with galvanized base brackets. Cut and laminate two 2x boards together to create the support beam, resting it inside notched post tops or rated post-to-beam steel brackets. Verify the beam is parallel to the ledger and level across its entire length.
- • Beam rests flat inside structural post brackets or shoulder notches.
- • Spirit level bubble is centered on both the top edge and face of the beam.
- • Temporary 2x4 diagonal braces hold posts rigidly vertical.
- • Relying entirely on through-bolts in shear instead of bearing the beam directly on top of the post shoulders.
- • Failing to check post plumb in both directions before securing brackets.
Install Outer Rim Joists and Square Frame
Attach the two outer rim joists from the ledger ends to the beam and fasten the front rim joist across them. Measure diagonally from opposite corner to opposite corner to check for squareness. Adjust the outer frame until both diagonal measurements match exactly.
- • Outer rim joists meet at clean 90-degree flush corners.
- • Diagonal tape measurements from corner to corner match within 1/8 inch.
- • Measuring diagonal length from different reference points on opposite corners.
- • Fastening middle joists before verifying outer perimeter squareness.
Layout Joist Spacing
Hook your tape measure on the end rim joist and mark joist positions along the ledger board and front rim joist at 16 inches on center (or 12 inches for diagonal composite decking). Draw vertical lines using a speed square and mark an 'X' on the side of the line where the joist will sit. Ensure marks on both ledger and rim match identically.
- • Clean pencil lines across the top and face of both the ledger and front rim.
- • Clear 'X' marks indicating the exact joist seat side next to each line.
- • Marking joist centers instead of edges, leading to offset joist placement.
- • Pulling layout from the outer face of the rim on one side and inner face on the other.
Crown and Install Field Joists
Sight down the edge of each joist to identify its natural curve (the crown) and mark the upward bow with an arrow. Cut joists to exact length and place them into the frame with the crowned edge pointing upward. Toenail or screw the joists temporarily into place on the layout marks across the ledger, beam, and rim.
- • All joist tops align flush with the top edge of the ledger and outer rim.
- • Upward crown arrows are visible on the top edges of all joists.
- • Joists sit firmly aligned with the pencil layout lines.
- • Installing joists with crowns facing down, creating dips and water-pooling spots in the finished deck.
- • Cutting joists too short, leaving excessive gaps at the ledger or rim.
Secure Joists with Metal Hangers
Slip metal joist hangers under each joist connection along the ledger board. Squeeze the hanger snug against the joist sides and drive approved 1-1/2 inch structural connector nails or screws into every single designated hanger hole. Ensure the joist remains tight to the ledger without lifting out of the hanger seat.
- • Every single stamped nail hole in each joist hanger is filled with a structural fastener.
- • Hangers are pulled tight against the joist face and bottom with no air gaps.
- • Using regular framing nails or drywall screws instead of rated 1-1/2 inch connector fasteners.
- • Leaving empty flange holes on the metal hangers.
Credit: inspired by an original tutorial by HouseImprovements — watch the original on YouTube.
Don’t have everything?
- No Palm nailer? 16 oz framing hammer
- No Self-adhesive flashing tape? Continuous roll-formed aluminum/copper ledger flashing