Post Caps & Accessories

Key Takeaways:

• Post caps protect railing posts from water infiltration and add decorative appeal
• Solar LED post caps cost $15–$60 each — provide free evening lighting with zero wiring
• Available in 4×4 and 6×6 sizes to fit standard railing posts
• Materials: copper, aluminum, composite, vinyl, and wood — match your deck's aesthetic
• Solar models charge in 4–6 hours of sunlight and illuminate 6–8 hours (less in winter)

Why Post Caps Matter

Railing posts are vertical end grain — the most vulnerable part of any wood structure. Without a cap, rain and snowmelt soak directly into the end grain, accelerating rot from the inside out. On pressure-treated posts, this can reduce post life from 20 years to 5–8 years. On cedar posts, even faster.

Post caps solve this by sealing the top and shedding water away from the end grain. They're also the easiest way to add personality and lighting to an existing deck.

Solar Post Cap Lights

Solar post caps are the fastest-growing deck accessory in Canada — they provide free deck lighting with no wiring, no electrician, and no operating cost.

Brand	Size	Price	Light Output	Charge Time	Run Time
Classy Caps (Canadian)	4×4, 6×6	$25–$60	2–10 lumens	6 hours	6–8 hours
Deckorators	4×4	$20–$40	2–6 lumens	4 hours	8 hours
Paradise by Sterno	4×4, 6×6	$15–$30	2–5 lumens	6 hours	6 hours
Moonrays	4×4	$12–$25	2–4 lumens	8 hours	6 hours

Winter performance note: in Prairie cities and Northern regions, solar caps may only illuminate 3–4 hours per night from November through February due to shorter daylight hours and snow coverage. Consider low-voltage wired alternatives for year-round reliability.

Non-Solar Post Caps

Copper Post Caps — $15–$45 each

Solid copper develops a natural green patina over time (like Parliament Hill's roof). Premium aesthetic for traditional or heritage homes. Available flat or with a ball/acorn finial.

Aluminum Post Caps — $8–$25 each

Powder-coated to match popular railing colours. Zero maintenance. Flat pyramid or contemporary styles.

Composite/Vinyl Post Caps — $5–$15 each

Colour-matched to Trex, TimberTech, and Fiberon composite railing systems. The most affordable option for a cohesive look.

Wood Post Caps — $3–$10 each

Cedar or PT caps in flat, pyramid, or ball styles. Can be stained to match the deck. Least durable — need replacement every 5–8 years.

Sizing Guide

Post Size (actual)	Cap Size to Buy
3.5" × 3.5" (4×4 nominal)	4×4 post cap
5.5" × 5.5" (6×6 nominal)	6×6 post cap
Aluminum railing post (varies)	Check manufacturer's specific cap
Composite sleeve over 4×4	Measure outside of sleeve

Cost for a Typical Deck

A standard 300 sq ft deck with railings has approximately 8–12 posts.

Cap Type	Per Cap	Total (10 caps)
Vinyl/composite	$5–$15	$50–$150
Aluminum	$8–$25	$80–$250
Solar LED (basic)	$15–$30	$150–$300
Solar LED (premium)	$30–$60	$300–$600
Copper	$15–$45	$150–$450