Best splash blocks

The Master Mark Chevron is the splash block I’d put under most downspouts. It scores 8.0, the top of this page, because it’s the only plastic block here with a way to anchor it and a published install guide.

Master Mark makes it from 100% post-consumer recycled plastic in Paynesville, Minnesota. Its page calls the material durable HDPE that won’t chip or crack, with a UV-stable, no-fade formula, and says the block fits any type of downspout.

Anchoring is the reason to choose it. Master Mark’s install guide says to place the block under the downspout elbow and, for added stability, push up to two stakes through the top tab. A light plastic block that isn’t staked can slide or flip in heavy runoff; the tab fixes that.

The install guide gives the size as 24 in. long and 11 in. wide. That’s the length that matters, because it sets how far from the wall the water lands. The placement check below shows why 24 in. isn’t enough on every lot.

Master Mark sells four colors, each with its own product code: black 30412, green 30712, gray 30612 and brown 30912. The Amazon listing for the brown block carries the black block’s 30412 code in its model field, so check the color in the photo and title rather than the code. I take half a point off the listing match for that.

The chevron pattern is decorative; Master Mark’s listing says the contours, depth and detail give a yard a modern look, and the block comes in black, green, brown and gray to match trim or mulch.

Master Mark doesn’t publish a warranty term for the splash block, which is the full check it misses. It also publishes no weight; the listing’s 1 lb earns half a point. Its page says its products are crafted by American workers since 1966, and the company is Avon Plastics.

Buy stakes with it. Master Mark sells landscape stakes and anchors as a separate line, and its guide is clear that stakes aren’t in the box.

The Emsco stone-texture block scores 7.7, just behind the Master Mark. It wins on paperwork: Emsco publishes its size, weight, material and a written warranty, and the Amazon listing matches all of it.

Emsco’s specifications give 24.25 × 11.25 × 2 in. and 0.9166 lb per block, in granite, hunter green or sand. The listing is a four-pack, which covers a house with four downspouts in one order.

Emsco describes the material as a composite blend of UV-stable polyethylene, lightweight and resistant to cracking, chipping and water damage, molded with a realistic stone design. The listing says Emsco is an American manufacturer selling products since 1865.

Its weak spot is weight. At under a pound, it relies on the ground and the downspout elbow to hold it, and there’s no stake tab. On a steep slope or under a downspout that drains a big roof, set it into the soil slightly or edge it with stone so it can’t slide.

Emsco’s warranty is stated plainly: unless otherwise stated, all Emsco Group products carry a 1-year limited manufacturer’s warranty from the date of purchase. That’s the only written warranty among the picks.

Emsco doesn’t publish install steps for the block, which costs it a point. There isn’t much to it: the block goes under the elbow with the closed end at the downspout and the open end pointing away from the house.

At just over 24 in. long, it lands water about as far from the wall as the Master Mark block. On expansive soil that’s short of the 5 feet the IRC asks for, so pair it with an extension.

Emsco is based in Girard, Pennsylvania, and lists the block on its own store as its premium splash block.

The NuCast concrete block scores 7.5. It’s the classic gray concrete splash block, and its weight is the whole point: at 50 lb it stays where you put it.

NuCast’s cut sheet gives the details: wet-pour precast concrete, 3 in. high, 11 in. wide and 29-1/2 in. long nominal, weighing 50 lb, shipped 40 to a pallet. The listing rounds the length to 30 in..

The drawing shows a 6 in. channel between two raised walls about 2-1/2 in. wide, closed by the full 3 in. end wall at the downspout end and open at the far end, where a low sloped nose lets the water out. The walls keep water running straight down the block instead of spilling over the sides near the foundation.

It’s also the longest pick, so it lands water a little farther from the wall than the 24 in. plastic blocks. That still isn’t the 5 feet the IRC asks for on expansive soil; see the placement check.

Concrete has one maintenance note. NuCast says precast concrete is naturally porous and can take on water damage, and suggests a silicone-based sealer to protect it. Seal it before you set it, while all sides are easy to reach.

NuCast is based in Redford, Michigan, and the listing says the blocks are made in the USA with locally sourced materials. It lists one size only.

It loses points for having no published warranty and no install guide, and for porosity, which NuCast itself flags. Placement is the same as any splash block: closed end under the elbow, open end away from the house.

Carry it with two hands and bend your knees; at 50 lb, it’s the heaviest thing on this page by a long way. NuCast’s cut sheet lists 40 blocks to a pallet, which suits a builder setting blocks at several houses.