2x3 or 3x4 downspouts?

2x3 is standard for most residential 5" gutters. Upgrade to 3x4 for 6" gutters, large roof areas, or high-rainfall regions.

How many downspouts do I need?

One downspout per 30-40 linear feet of gutter, or one per 600 sq ft of roof area.

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Gutters & Drainage

Gutters

Budget: $3-$6 per 10 ft section (aluminum 2x3) | Mid-range: $6-$12 per section (3x4 or colored) | Premium: $10-$20 per section (decorative or copper)

Downspouts: Rain Gutter Downspout Pipe & Accessories (2026)

Prepared by Lumberama's Building Materials Team

|Last updated May 25, 2026|Sources & methodology

Downspouts are the vertical pipes that carry rainwater from gutters down to ground level and direct it away from the foundation. Available in rectangular (2x3 and 3x4) and round profiles, they connect to gutter outlets with elbows and extend to splash blocks or underground drain pipes at grade.

Key Features

Rectangular and round profiles; 2x3 and 3x4 standard sizes; Aluminum and vinyl materials; Color-matched to gutter system; Complete accessory system (elbows
extensions)

Specifications

Sizes: 2x3"

3x4" rectangular

3" and 4" round | Material: aluminum

vinyl

galvanized | Length: 10 ft sections | Elbows: A (75°)

B (45°) | Extensions: hinged swing-up style | Straps: standoff brackets

Applications

Directing roof runoff to grade; Connecting gutters to underground drains; Rain barrel collection input; Foundation water protection; Extending water away from structure

Installation Overview

Connect outlet drop to gutter outlet. Attach upper elbow (A-style) to transition from gutter to wall. Connect straight pipe sections. Attach lower elbow to direct water away from foundation. Secure with standoff brackets every 6 feet. Add extension at bottom for ground-level discharge.

Pros & Cons

Pros

✓ Essential component of gutter system; Directs water away from foundation; Easy to assemble with elbows; Color-matched to gutter system

Cons

✗ Can clog with debris; Must be properly sized for flow; Elbows reduce flow capacity; Extensions can be unsightly

Top Brands

Amerimax

Spectra Metals

Genova

Code Requirements

Must discharge water minimum 6 feet from foundation or connect to approved drainage system. Must be securely attached to structure. Sizing must handle roof area runoff.

Buying Tips

Size downspouts to match your gutter size (2x3 for 5" gutters, 3x4 for 6"); Buy extra elbows - you typically need 3 per downspout location; Add downspout extensions to direct water at least 6 feet from the foundation