Deck Inspection Guide
What building inspectors look for at each stage, the most common reasons decks fail inspection, and how to pass on the first try.
Inspection Overview
2-3
Inspections required
15-30 min
Per inspection
24-48 hrs
Scheduling notice
Before Every Inspection
- Post your approved permit in a visible location at the job site
- Have a copy of the approved plans available for the inspector
- Ensure the inspector has clear access to all areas being inspected
- Clean up the work area — remove debris and construction waste
- Do NOT cover up or proceed past the work being inspected
- You or your contractor should be present for questions
Footing / Foundation Inspection
When: After digging holes and before pouring concrete
What Inspectors Check
- Hole depth extends below the local frost line
- Hole diameter meets minimum footing size (typically 16-24 inches)
- Soil at the bottom is undisturbed (not backfilled)
- Rebar or reinforcement is placed correctly (if required)
- Location matches the approved site plan
- Setback distances from property lines are correct
Common Failures
- Footings not deep enough for the local frost line
- Holes dug in wrong location vs. approved plan
- Disturbed or soft soil at the bottom of the hole
Tips to Pass
- Call for inspection BEFORE pouring concrete — inspectors need to see the hole
- Have your approved permit and plans on site
- Use a tape measure to verify depth and diameter before calling
Framing / Structural Inspection
When: After framing is complete, before decking is installed
What Inspectors Check
- Ledger board is properly attached with lag screws or through-bolts (not nails)
- Flashing is installed behind and over the ledger board
- Joist size, spacing, and spans match approved plans and code tables
- Beam size and post spacing match approved plans
- Post-to-beam and post-to-footing connections use approved hardware
- Lateral bracing is installed per code
- All lumber is pressure-treated or naturally durable species
- All hardware and fasteners are corrosion-resistant (galvanized or stainless)
Common Failures
- Ledger attached with nails instead of lag screws/bolts
- Missing or improperly installed flashing
- Joist spans exceeding code tables for the lumber size used
- Missing joist hangers or using wrong size hangers
- Posts notched instead of using post caps
Tips to Pass
- Do NOT install decking yet — inspectors need to see the framing
- Have joist hanger manufacturer specs available if asked
- Verify every connection has the correct hardware before calling
Final Inspection
When: After all work is complete, including railings, stairs, and decking
What Inspectors Check
- Railing/guard height meets minimum (36 inches residential, 42 inches in some areas)
- Baluster spacing is 4 inches or less (4-inch sphere test)
- Stair risers are uniform (max 3/8-inch variation)
- Stair tread depth is minimum 10 inches
- Handrail on stairs with 4+ risers, graspable (1.25-2 inch diameter)
- Decking is properly fastened with correct fastener type
- Deck surface drains properly (slight slope away from house)
- Electrical work (if any) has separate electrical inspection approval
- Overall structure matches approved plans
Common Failures
- Railing height too short (measured from deck surface, not between boards)
- Baluster spacing too wide — the 4-inch sphere test catches most of these
- Stair riser inconsistency — even 1/2 inch variation is a fail
- Missing handrail on stairs
- Deck boards with no gap for drainage
Tips to Pass
- Walk the entire deck and test every railing section for stability
- Use a 4-inch sphere (a softball is close) to test every baluster gap
- Measure every stair riser with a tape measure
- Clean up the site — debris and construction waste suggest unfinished work
What If You Fail an Inspection?
Failing an inspection is common and not a penalty. It simply means something needs to be corrected before work can continue.
- The inspector leaves a correction notice listing specific failures
- Fix the listed issues (and only those issues — don't change anything else)
- Call to schedule a re-inspection (usually 1-2 free re-inspections)
- After the allowed free re-inspections, expect a fee of $50-$100 per visit
The key is to fix exactly what was noted — nothing more, nothing less. If the correction notice says "railing height 34 inches, must be 36 inches minimum," fix the railing and call back.
Frequently Asked Questions
How many inspections does a deck permit require?
Most deck permits require 2-3 inspections: footing/foundation, framing/structural, and final. Some jurisdictions combine the footing and framing inspections into one. Complex decks with electrical may require an additional electrical inspection.
What happens if I fail a deck inspection?
The inspector will note the specific failures on a correction notice. You fix the issues and call for a re-inspection. Most jurisdictions allow 1-2 free re-inspections; after that, there may be a re-inspection fee ($50-$100). Failing is common and not a penalty — it's part of the process.
Can I use the deck before final inspection?
Technically no — using a structure before it passes final inspection violates most building codes. If an injury occurs on an uninspected deck, your liability exposure is significant. Wait for the Certificate of Completion.
How long does a deck inspection take?
The actual inspection takes 15-30 minutes. Scheduling the inspection typically requires 24-48 hours notice. Some busy jurisdictions may have a 1-2 week wait for inspection appointments.
Do I need to be present for the inspection?
You or your contractor should be present. The inspector may have questions about the construction or need access to areas that aren't obvious. Having the permit holder present speeds up the process.
What documents do I need at the inspection?
Have your approved permit posted visibly, a copy of the approved plans, any engineering reports (if required), and hardware/lumber specifications. Some inspectors will ask for manufacturer specs for post bases, joist hangers, or composite decking.
Building Code Reference
Complete IRC R507 requirements: spans, loads, railings, stairs.
Deck Permit Guide
Do you need a permit? Costs, requirements, and how to apply.
Inspection requirements vary by jurisdiction. Your local building department may have different inspection stages, requirements, or procedures. This guide is based on common practices following the IRC. Always follow your local building department's specific instructions.