Weep Hole — Wall Drainage Openings and Common Issues

A weep hole is a small opening left in an exterior assembly so trapped water can drain out and air can circulate behind masonry, windows, or siding.

Weep Hole diagram — labeled parts, dimensions, and installation context

What It Is

Weep holes are intentional drainage points, not construction defects. They let incidental water escape from wall cavities or window frame channels before it damages surrounding materials.

Types

Common forms include open head joints in brick veneer, plastic weep vents, slotted holes in window frames, and drainage openings at the bottom of some metal or vinyl siding accessories.

Where It Is Used

They are used at the base of brick veneer walls, above flashings, at window and door frames, and in some manufactured cladding systems. Their location is tied to the drainage path of the assembly.

How to Identify One

Identify a weep hole by looking for evenly spaced small openings near the bottom of a wall or frame. Paint, caulk, mulch, or insect nests blocking these openings can trap water and cause hidden moisture damage.

Replacement

Replacement is less about changing the hole itself and more about restoring drainage. That may mean cleaning blocked openings, replacing missing vents, repairing failed flashing, or reopening drainage paths that were sealed shut.

Weep Hole — FAQ

Are weep holes supposed to be open?

Yes. They are designed to let water drain and should not be caulked shut. Blocking them can trap moisture inside the wall or frame assembly.

Why do I see water coming out of a weep hole?

That is often normal during rain or after window condensation drains out. The opening is doing its job by letting water escape instead of staying trapped.

Can bugs get in through weep holes?

They can, which is why some systems use screened or vented inserts. Even so, the drainage opening should remain open enough to function.

Should mulch or soil cover brick weep holes?

No. Landscaping should stay below them so the wall can drain and dry. Covered weep holes are a common cause of moisture problems at lower brick walls.

Do windows have weep holes too?

Many do. Small slots at the bottom of aluminum, vinyl, and some clad frames help drain water out of the frame system.