Drain on Side of House: What That Pipe Is and How to Fix It

When people search "drain on side of house," they usually mean one of two things. It might be a small pipe sticking out of the wall that drips or runs now and then. Or it might be water that runs along the side of your house and pools in the narrow strip between your home and the next one. The first is usually a plumbing or heating question. The second is a drainage problem, and it is the one that can end up in your basement.

This post covers both. We start with a quick way to identify the drain pipe on the side of your house, then spend most of the time on side of house drainage: why water collects there and how it is fixed, from the smallest change to the largest.

First, what is that pipe on the side of your house?

If the "drain" you are looking at is a short pipe coming through the wall, it is almost always one of these:

• Air conditioner condensate line. A small plastic or copper pipe near the outdoor AC unit or an inside air handler. It drips while the AC runs in summer. That is normal.
• High-efficiency furnace or boiler line. White PVC pipes through the wall, often two side by side. One may drip condensate in winter. Also normal, as long as the drip doesn't freeze into a hazard on a walkway.
• Relief valve discharge. A pipe from the water heater or boiler relief valve. It should be dry. If it drips or runs, call a plumber, because the valve is telling you something is wrong.
• A pipe coming out of the ground. Near the base of the house, this is often the end of a buried downspout line or an old footing drain. If it runs during rain, it is doing its job. If it never runs, it may be crushed or clogged.

The first three belong to an HVAC technician or a plumber, not a mason. The rest of this post is about water on the ground.

Why water collects along the side of a house

Side yards in older neighborhoods around Woburn and the towns nearby are often narrow, shaded and squeezed between two houses. Water gathers there for a few common reasons:

• Downspouts that empty into the side yard. A downspout drains a big piece of roof. When it dumps at the corner of the house with nowhere to go, that water soaks in right against the foundation.
• Soil that slopes the wrong way. The soil dug out to build the foundation was put back loose. Over the years it settles, and the ground right next to the wall ends up lower than the ground a few feet out.
• Water from next door. If the neighbor's lot sits higher, or their downspouts point your way, their runoff ends up on your side.
• A driveway or walk that sheds water toward the house. Hard surfaces don't absorb anything. If they pitch toward the wall, the water runs straight to it.
• Slow soil. Clay, packed fill and ledge (bedrock close to the surface) are all common north of Boston, and none of them take water quickly.
• Snow piles. Snow shoveled off a driveway into the side yard melts there in spring, often right along the foundation.

Find the source before choosing a fix

The best time to look is during a steady rain. Put on a raincoat and walk the side of the house. Watch where the water comes from, where it goes, and where it stops. Check whether each downspout is attached, whether the gutter above is overflowing, and whether water is coming across from the neighbor's yard.

Then look at the slope. The International Residential Code, which the Massachusetts residential building code is based on, calls for the ground to fall at least 6 inches within the first 10 feet away from the foundation (IRC section R401.3). In a side yard that is only 6 or 8 feet wide, you may not have 10 feet to work with. That is exactly why side yards cause so much trouble, and why the fix there often moves water along the house to somewhere else instead of straight away from it.

If the gutters are clogged or overflowing, have a gutter company clean or repair them first. That alone can solve a side yard problem.

How side yard drainage is fixed, smallest to largest

1. Redirect the downspout

A longer extension or a turned elbow can carry roof water to the front or back of the house where the ground slopes away. In a narrow side yard, though, extensions get stepped on and buried in snow.

2. Regrade the soil against the foundation

Rebuilding the soil so it slopes away from the wall, with a dense soil that sheds water on top, fixes many wet corners. Keep the finished soil below the siding and any wood trim. A thick layer of mulch or loose stone piled against the house without a slope under it only holds water at the wall.

3. Shape a shallow swale

A swale is a gentle, grassed or stone-lined dip that runs the length of the side yard and carries surface water toward the front or back of the lot. It works well between two houses, because it moves water along the narrow strip instead of trying to push it uphill. The swale has to end somewhere lower, and it should not dump water onto a neighbor's property.

4. Pipe the downspout underground to a dry well

When there is no good place for the water to run on the surface, a solid pipe buried in the side yard can carry roof water to a dry well farther from the house. The pipe needs a steady downhill fall so it drains completely and doesn't freeze full of water. The dry well needs soil that drains and enough distance from the foundation. Our post on dry wells versus French drains explains when each one fits.

5. Add a French drain where groundwater is the cause

Sometimes the water is not coming off the roof at all. It seeps out of the ground, often from a slope above the house, and the side yard stays soggy for days after a storm. A French drain, a trench with perforated pipe in washed stone, can catch that water and carry it to a dry well or to daylight. For larger foundation water problems, see our guide to drainage around the house foundation.

Call Dig Safe before anyone digs

Side yards are where gas lines, water services and electrical lines often run into the house. In Massachusetts, state law requires notice to Dig Safe at least 72 hours before digging, not counting weekends and legal holidays (Dig Safe FAQ). A contractor should file the ticket and wait for the marks before excavating.

When to call a mason

Call for help when water is already reaching the basement, when the fix needs digging, piping or a dry well, or when you can't tell where the water is coming from. Signs that water has been working on the wall for a while include damp spots on the inside of the foundation on that side, white mineral deposits on the wall, and crumbled mortar at the base of a stone foundation.

Gerrior installs French drains, dry wells, underground downspout piping and regrading, and we repair the foundation masonry the water has damaged. Owner Joseph Gerrior oversees the work. See our foundation, bulkhead and drainage repair page for the full service. One Reading customer wrote about a drainage job we did for them:

"Joe and his crew just finished up a drainage job for us. They were on time, great to work with (as usual) and the guys always friendly. They were very careful in the yard and Joe was excellent with the little excavator." Larry P., Reading, MA

Common questions

Is water dripping from the pipe on the side of my house a problem?

A drip from an AC condensate line in summer, or from a high-efficiency furnace line in winter, is normal. A dripping relief valve pipe from a water heater or boiler is not; call a plumber.

Can I just put gravel along the side of the house?

Gravel by itself doesn't move water. If the soil under it slopes toward the house, the gravel just lets water soak in at the wall faster. Fix the slope underneath first. Gravel on top of a properly sloped bed is fine.

Do I need a permit to install a dry well?

It depends on your town and the site. Our post on dry well permits in Massachusetts covers what to check.

If water keeps collecting along the side of your house, we can look at the site, find where the water comes from and explain the options. Gerrior Masonry & Landscape Construction Corp. is a family-owned company in Woburn, MA, with over 30 years in masonry and drainage work. We are fully insured, our work is guaranteed, and estimates are free. Call (781) 933-4157 or request a free estimate.