Downspout adapters

The Aquabarrel 3x4x4 is the adapter I’d reach for first. It scores 8.5, the top of this page, because it adjusts to fit and Aquabarrel publishes exactly how far it adjusts.

The headache is height. A buried drain pipe rarely ends exactly where the downspout does. Aquabarrel’s adapter telescopes: collapse the upper part into the lower body, set the lower body into the round pipe, then pull the upper part up to meet the downspout. Aquabarrel holds a utility patent on the design (No. 12196353).

Aquabarrel gives the numbers: 4.125 in. tall fully collapsed, 6 in. fully extended, about 1.75 in. of travel on its ladder tracks, and a 1.5 in. deep socket for the downspout. Inside corners have a minimal radius to suit square downspout corners.

The lower body is a universal 4 in. coupling. Aquabarrel says it fits inside any 4 in. round pipe: SDR 28, SDR 35, Schedule 40 PVC and 4 in. corrugated. The listing adds that triangles on the sides grab and lock in corrugated pipe, with smaller grips for smooth wall, and a wide collar hides the cut end of the pipe.

The listing also says the adapter is slightly oversized so the downspout slips in more easily. Downspouts are rarely exactly 3 × 4 in., so that slack is useful.

It loses half a point because Aquabarrel describes the material only as weather resistant, and a full point for having no drawing or manual beyond the product page.

Aquabarrel sells the same design for other sizes, including 2x3x4 and 4x5x4, in black or white. Pick the color to match the downspout if the joint will show.

Leave the downspout loose until the adapter is set in the pipe, then pull the upper part up to meet it. That’s the order Aquabarrel describes, and it saves fighting a fixed downspout into a fixed fitting.

The ADS 0465AA scores 7.8. ADS makes black corrugated drain pipe, and this is its own adapter for that pipe.

ADS’s product table gives the size: 4 in. pipe × 4.25 in. × 3 in. downspout, packed 20 to a case. That 4.25 × 3 in. opening is what the trade calls a 3x4 downspout. The Amazon listing describes the same thing: a 3 in. × 4-1/4 in. downspout to 4 in. round poly drain tube, quantity 20.

ADS publishes the whole family. The 0364AA fits 3 in. pipe with a 3.25 × 2.5 in. (2x3) opening, the 0464AA fits 4 in. pipe with the same 2x3 opening, the 0466AA takes a 2.56 in. square downspout, and the 0664AA goes to 6 in. pipe. Its singlewall fittings manual includes a drawing (No. 6010) of the downspout adapters.

It’s polyethylene, like the pipe. ADS’s listing for the 0464AA calls the material crack and corrosion resistant.

It loses points on fit flexibility. ADS names its own poly drain tube as the match; it doesn’t list SDR or Schedule 40 PVC on the product table, and the adapter doesn’t adjust in height.

Watch for listings that stretch the claim. Amazon’s ADS 0464AA listing says it fits both 2x3 and 3x4 downspouts, but ADS’s table lists the 0464AA opening as 3.25 × 2.5 in. only. Buy the part number for your downspout size.

Another listing under the Mutual Industries brand carries ADS’s 0465AA part number. I picked the listing under the ADS brand so the part matches ADS’s documents.

A case of 20 makes sense for a contractor or a house with many downspouts; for one downspout, the Aquabarrel or a single Gutterworks adapter is the smaller buy.

The Gutterworks 3x4x4 scores 7.0. Its strength is fit: the listing says it goes into black corrugated pipe and inside smooth-wall PVC SDR 28, SDR 35, Schedule 40, clay and cast iron pipe, the widest list here.

That matters where a downspout drains into existing clay or cast iron tile: an adapter that fits inside the old pipe connects a new downspout without replacing the line.

Gutterworks makes the adapters at its own plant in Iowa, and sells 13 sizes: 2x3x3, 2x3x4, 3x4x3, 3x4x4, 3x4x6, 4x4x4, 4x4x6, 4x5x4, 4x6x4, 4x5x6, 4x6x6, 5x5x4 and 6x6x6, in black or white. The first two numbers are the downspout, the last is the round pipe.

Gutterworks adds a useful warning: 2x3, 3x4, 4x5 and 4x6 are generic names, and real downspouts may measure 2-1/4 × 3-1/4 in. or similar. Measure yours before you order.

It scores lower because Gutterworks doesn’t publish dimensions beyond the size name, calls the material simply plastic and gives no joint detail beyond fitting inside the pipe. Its larger sizes carry design patents, per Gutterworks’ 4x5x6 page.

The listing is a case of 6, priced per case, which suits a whole house or a contractor’s truck. Gutterworks also lists a 2x3x4 black case of 6 and single larger sizes.

For a single 3x4 downspout into 4 in. pipe, the Aquabarrel is the easier buy; for clay or cast iron, or several downspouts, this is the one.

Check the color: the listing picked here is white, and the black version is a separate listing with its own TAB34-4 part number. Gutterworks also sells 3x4-to-2x3 downspout adapters, in black and white, for houses that mix the two sizes. Its company address is Barnes City, Iowa, per its site.

The Aquabarrel 2x3x4 scores 8.5, the same as its 3x4 sibling, because Aquabarrel publishes the same full spec for it. It’s the pick for houses with 2x3 downspouts.

Its job is the same: telescope to meet a downspout that doesn’t line up with the pipe. Aquabarrel’s 2x3x4 page gives the same numbers as the 3x4x4: 4.125 in. tall collapsed, 6 in. extended, about 1.75 in. of travel and a 1.5 in. deep socket.

The bottom is the same universal 4 in. coupling, which Aquabarrel says fits inside SDR 28, SDR 35, Schedule 40 PVC and 4 in. corrugated pipe. The listing describes it as a 2 in. × 3 in. gutter opening on one end and a 4 in. round connection on the other.

Moving from a 2x3 downspout to 4 in. pipe is a step up in size, which gives the water room once it’s in the line. ADS’s 0464AA and Gutterworks’ 2x3x4 do the same job without the height adjustment.

Aquabarrel’s page also lists a 2x3x4 offset adjustable version, for a downspout that sits close to the wall and a pipe that comes in a little farther out.

It shares the 3x4’s gaps: Aquabarrel calls the material weather resistant without naming it, and publishes no drawing or manual. Aquabarrel holds a utility patent on the design (No. 12196353), per its product page.

Black and white are both sold; the black one on Amazon carries Aquabarrel’s part number a234blk. Match the downspout color if the joint will show above ground.

Install order is the same as the 3x4: set the collapsed adapter into the pipe first, then pull the upper part up to meet the downspout and secure it.