Should I Build a Deck Myself or Hire a Contractor?
Quick Answer: Building a deck yourself is technically possible for a skilled, experienced DIYer – but most homeowners significantly underestimate the complexity, especially in Illinois. Proper footings below the frost line, ledger flashing, composite manufacturer installation requirements, and the permit/inspection process all require knowledge and execution that is genuinely difficult for first-timers. For composite decking specifically, improper installation can void the product warranty. For most homeowners, hiring a qualified contractor delivers a better result at a total cost that’s closer to the DIY option than it seems.
What DIY Deck Building Actually Requires
Most homeowners who consider building their own deck think about laying boards. That’s maybe 20% of the project.
The rest involves:
Footings: Augering holes to 42 inches below grade in Illinois soil (which in the Fox Valley area often includes heavy clay), pouring concrete properly, setting post bases at the correct height and alignment. Getting this wrong means a deck that heaves or settles. You’ll need to rent an auger.
Ledger attachment: Flashing the ledger board against the house correctly is one of the most technically demanding parts of deck construction. Do it wrong and you rot your rim joist within 5 to 10 years. This requires understanding flashing materials, techniques, and often removing siding.
Framing: Sizing posts, beams, and joists correctly using span tables. Getting joist spacing right for the specific composite product being used (typically 12 inches on-center). Using the right fastener hardware and connectors.
The permit process: In Oswego, you can pull an owner-builder permit. But you still need to prepare site plan drawings and structural documentation for plan review. Then pass a framing inspection and a final inspection. The permit process in Oswego and Kane County is real work even before construction starts.
Composite installation specifics: Composite decking has specific installation requirements – gap sizing for thermal expansion, hidden fastener systems, proper end treatment, joist spacing requirements from the manufacturer. Installing it incorrectly voids the product warranty.
Where DIY Decks Most Commonly Go Wrong
The problems we most often see on homeowner-built decks:
- Footings that weren’t dug deep enough and have heaved
- Ledger boards with no flashing, causing rim joist rot
- Railing posts attached only to the decking surface (not through to the framing) – a safety hazard
- Joist spacing wrong for the composite product installed – boards deflect in heat
- No permit – which creates insurance and real estate complications
These are not cosmetic problems. Most of them are structural or safety issues.
The Honest Cost Comparison
Where DIY looks most attractive is cost. You save the labor portion of a contractor’s quote – which is real money.
But account for:
- Equipment rental (auger, concrete mixer or delivery, specialized composite cutting equipment)
- Material waste from inexperience
- Your time (this is a week or more of full-time work for two people on a mid-size deck)
- The potential cost of mistakes – structural problems caught during inspection, or not caught during inspection but failing later
For many homeowners, the actual cost difference after all factors is smaller than expected. And the risk of a mistake – particularly on the structural elements – is higher.
When DIY Makes More Sense
If you’re a skilled carpenter or tradesperson who regularly works with framing and has done similar projects before, a DIY deck is a legitimate undertaking. Experience building structures matters enormously.
If you’re drawn to the project aspect and want to build something with your hands, that’s a real value even beyond the cost savings.
If the deck is very simple – a small, ground-level freestanding deck with no ledger attachment – the risk profile is lower than an elevated attached deck.
Important Considerations
The composite warranty is tied to installation. If a composite manufacturer’s warranty is something you’re counting on, verify that the warranty is valid for owner-installed products (some have specific installation requirements that are easier to meet with a professional contractor).
Inspections catch problems. Whether you DIY or hire, getting the permit and passing inspections is what gives you independent verification of the structural work. Don’t skip this step.
Choosing a qualified deck builder in Oswego – what to verify and what to ask.
What to Do Next
Get a professional estimate before you commit to DIY. Know what the number actually is. Then make an informed decision.
Call DDT Deck Builders at 630-200-3945 for a free estimate. We serve Oswego, Aurora, Montgomery, Yorkville, Plainfield, and Kane and Kendall County.