If they're clogged, open them up with a brush, a screwdriver or a toothpick. Clear away leaves, twigs and dirt that accumulate on the windowsill.
At times some of the weep holes can also be blocked by insects getting into the weep holes and nesting. This can lead to a build up of water in the extrusion and cause extensive damage to the rough openings and walls.
While you should never fill weep holes with solid material—such as caulk, wood, or mortar—you can put strips of fiberglass screen wire or a scouring pad in the weep holes to keep insects out.
Method 1 - Remove Build-up
Find the weep holes by unscrewing the plug hole/top part of the drain hole. Look inside and you will see small holes around the outside of the main pipe. Stick a piece of thin wire through the holes if you see a white, crusty build-up.
If you notice one is clogged, all you really need to do is to grab a really thin, straight object such as eye-glasses screwdriver. Find the outside exit of the weep hole and gently clear it out with the end of your tool, then find the inside and push any debris through from there as well.
Sealing window weep holes can cause excessive condensation and water build-up leading to rotting of the window sill and frame. Sealing retaining wall weep holes can cause stability issues for the wall as any water behind the wall cannot escape which in turn increases hydrostatic pressure on the structure.
If you plug the weep hole the seal will continue to leak and it will pressure up the cavity between the seal and the pump shaft bearing. This will force the coolant through the bearing and out the other side. So the leak will reappear very quickly just via another route.
Don't use steel wool in weep holes
While steel wool has many uses, the material is not designed for use outside and decays quickly, exposing an entry point for pests. You may also be left with staining on your brickwork or render as the steel wool rusts.
The absence or the obstruction of weep holes promotes water infiltration inside the walls and may cause damages that are not always visible. To prevent this, it is recommended that the weep holes in the masonry joints are never blocked.
Prior to floating my pan mortar, I remove the strainer from the drain collar and lightly coat the collar and the adjacent pan material with 3M spray adhesive. Then I unfold a paper coffee filter, place it over the collar and mold it into position so that the weep holes are protected.
ANSWER - Having wet grout around the drain does suggest that the weep holes at the waterproof membrane level might be plugged.
As an alternative to weep holes, most new construction will connect the drainage zone to a perforated drainage pipe located behind the base of the wall outfalling to a manhole.
If you seal these holes completely you can disrupt your weep hole drainage. Sealing them to prevent pest entry can result in moisture becoming trapped inside your cavity walls.
A weep hole can be blocked by excess dirt or debris that might collect in it with time. With this blockage, any water that passes around doesn't end into the sill but instead leaks around.
Weep holes are often located at the bottom of brick exterior walls. They look like vertical gaps in the mortar joints between bricks. Because brick masonry is porous, water may penetrate the surface and get behind the wall.
The Weep Vent should be spaced at no greater than 900mm centres to meet N.H.B.C guidelines, which state, “weep holes are recommended to be sited at every 450mm maximum with at least two per opening above all windows and doors.”
One important tip is to make sure you don't cover the weep holes on the house. If you do, it could lead to some serious flooding issues and cause damage to your floors!
Do I Need To Plug Weep Holes During a Flood? No. Unless your home is a submarine the exterior materials along with doors and windows are not watertight and will succumb to the flood waters.
Furthermore, if you block your weep holes in an attempt to solve that problem then you will prevent the drainage of that water and the airflow needed to completely dry the cavity. This will likely cause catastrophic problems.
Check weep holes at least once a year, before the rainiest season. If they're clogged, open them up with a brush, a screwdriver or a toothpick. Clear away leaves, twigs and dirt that accumulate on the windowsill.
Problems With Weepholes
If weep holes are left unprotected in brick walls they provide access to the wall cavity for rodents and insects. Swarming bees and European Wasps love creating nests in cavities.