10/12/2026
LETUS Lesson 00065
Not All Screws
Are Made for All Wood
When repairing a deck, fence, porch, or other outdoor wooden structure, choosing the right fastener is just as important as choosing the right lumber.
Pressure-treated wood is commonly used outdoors because preservatives help protect it against decay and insect damage. However, some of the chemicals used in pressure treatment can accelerate corrosion in certain metals.
That means an ordinary screw that works perfectly well indoors may not be suitable for pressure-treated lumber.
Here’s what property owners should know:
• Standard drywall screws are generally not suitable for exterior structural wood applications. They lack the corrosion protection and performance characteristics needed for many of these uses.
• Hot-dip galvanized fasteners are commonly used with pressure-treated lumber, provided their coating meets the requirements for the specific application.
• Stainless steel fasteners can provide excellent corrosion resistance, particularly in coastal areas or other highly corrosive environments.
• Some exterior-rated coated screws are specifically approved for use with pressure-treated lumber, but not every screw labeled “exterior” is compatible with every treatment.
• Fasteners and metal connectors should also be compatible with one another to help avoid galvanic corrosion.
Using incompatible fasteners can eventually lead to rust, staining, weakened connections, and premature failure.
And remember, corrosion resistance doesn’t automatically mean a screw is structurally appropriate. Deck framing, joist hangers, railings, and other load-bearing connections may require specific fasteners approved for those applications.
Pro Tip:
Before purchasing screws for pressure-treated lumber, check the packaging for compatibility with the wood treatment and intended application. When using structural connectors, follow the connector manufacturer’s fastener specifications rather than substituting ordinary screws.
A small decision at the hardware store can make a significant difference in how well an outdoor repair holds up over time.
You can choose to do everything yourself
or
You can ‘Leave Everything To US’
LETUS | Leave Everything To US
Maintenance LLC
Residential & Commercial
Repairs | Upkeep | Installations
(704) 269-8295
letusmaintenance.com
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