Why does a louvered pergola drip in the morning?

You step outside on a clear morning, and drops of water are falling from the underside of the louvers. It didn’t rain overnight. Where did the water come from?

In most cases, it’s condensation. Water from humid air collects on surfaces that cooled down overnight. This article explains why it happens, how to tell it apart from rain water, and what you can do to reduce it.

Why does condensation form on the louvers?

On a clear night, outdoor surfaces lose heat to the open sky and can get cooler than the air around them. When the air is humid, moisture from that air settles on the cool surface as small drops. That’s the same dew you see on grass, cars, and patio furniture in the morning.

Metal roofs, car roofs, and outdoor furniture can all collect dew. The underside of closed louvers can, too, especially on still, humid mornings.

When is condensation most likely?

Dew tends to form when:

• The night is clear, with few clouds
• The air is humid
• There’s little or no breeze
• It rained recently, so the air and ground are damp

You may notice it more in certain seasons or in humid climates. On cloudy or breezy nights, you may see little or none.

How can you tell condensation from rain water?

Look at the pattern and the timing.

When the louvers are closed in rain, rain runs from the louvers into the beam channels and down through the posts. If you see water at one spot during or after rain, take photos and note the time. Before you order, email [email protected]. After you order, email [email protected].

What can you do to reduce morning drips?

A few simple habits can help:

• Open the louvers slightly in the evening. The louvers rotate from 0 to 120 degrees by remote control. A small opening lets air move under the roof overnight. Keep in mind that rain can then fall through, so close the roof if rain is coming.
• Open the louvers in the morning. Sun and air dry the drops faster.
• Bring cushions in overnight or cover them, so morning drips don’t soak them.
• Wipe the table and chairs before you sit down.
• Keep the area around the pergola clear, so air can move.

If you’re thinking about adding a fan, ask [email protected] before you order. See can you put a ceiling fan on a louvered pergola.

Is condensation bad for the pergola?

Dew is a normal part of outdoor life, and it forms on everything outside. A Louvano pergola has a powder-coated finish and 304 stainless steel fasteners. Care instructions are supplied with each pergola. See motorized pergola maintenance and does an aluminum louvered pergola rust.

Should the roof stay closed overnight?

That depends on the forecast. If rain is expected, close the louvers with the remote. If the night is clear and dry, you can leave them slightly open to let air move.

For more on rain, read can a louvered pergola keep you dry in the rain.

Where does the rain water go?

When the louvers are closed in rain, water runs from the louvers into the beam channels, down through the posts, and out near the post bases. Dew on the underside of the louvers forms below the roof, so it drips straight down. Ask [email protected] how to plan for the water that drains out near the post bases for your size and layout. For the full path, see how a louvered pergola drains water.

FAQ

Why is my pergola dripping when it didn’t rain?
It’s most likely condensation. Moisture from humid air settles on the louvers after they cool overnight.

How do I stop the morning drips?
Try opening the louvers slightly in the evening with the remote, and open them in the morning to help the drops dry. Close the roof if rain is coming.

How do I know it’s not rain water?
Condensation shows up as even drops across a wide area early in the morning. Water at one spot during or after rain is different. Take photos and email [email protected] before you order, or [email protected] after.

Does dew harm the finish?
Dew forms on all outdoor surfaces. Care instructions are supplied with each pergola.

More answers are on our FAQ page.