Are splash blocks enough?

Splash blocks redirect water 2-4 feet which is the bare minimum. Downspout extensions or underground drains that move water 6+ feet are much more effective.

Concrete is heavier and stays in place better. Plastic is lighter and easier to reposition but can blow around.

Splash BlocksGenerating image…

Gutters & Drainage

Drainage

Budget: $3-$7 (basic plastic) | Mid-range: $8-$15 (concrete or decorative plastic) | Premium: $15-$35 (decorative stone or polymer)

Splash Blocks: Downspout Drainage Blocks for Foundation Protection (2026)

Prepared by Lumberama's Building Materials Team

|Last updated May 25, 2026|Sources & methodology

Splash blocks are shallow, sloped trays placed under downspout outlets to direct rainwater away from the foundation. They prevent soil erosion and water pooling at the base of the home. Available in concrete, plastic, and decorative stone styles, they are a simple but essential component of roof drainage.

Key Features

Directs water 2-4 feet from foundation; Concrete
plastic
and decorative options; Prevents soil erosion at downspouts; No installation tools required; Sloped design channels water outward

Specifications

Materials: concrete

recycled plastic

polymer stone | Dimensions: 24" to 36" long

12" wide | Weight: 5-40 lbs | Colors: gray

brown

green

stone textures | Slope: built-in 2-3" drop

Applications

Under gutter downspout outlets; Foundation water protection; Soil erosion prevention; Temporary drainage solution; Decorative downspout termination

Installation Overview

Place splash block under downspout outlet with narrow end touching house. Angle the block to slope away from foundation. Ensure water exits at least 2 feet from foundation wall. Level the block so water flows outward, not backward. Reposition seasonally as settling occurs.

Pros & Cons

Pros

✓ Cheapest foundation protection option; No tools or installation required; Available in decorative styles; Prevents erosion at downspout discharge

Cons

✗ Only redirects water 2-4 feet; Can shift out of position; Must be reset after lawn mowing; Not effective for heavy rainfall

Top Brands

Amerimax

Quikrete

Master Mark

Code Requirements

IRC R401.3 requires roof drainage to be directed away from foundation. Splash blocks provide minimum compliance but downspout extensions or underground drains are preferred.

Buying Tips

Consider downspout extensions or underground drain pipe for better protection than splash blocks alone; Heavy concrete blocks stay in place better than lightweight plastic; Position blocks so water flows at least 2 feet from the foundation