What Are Weep Vents in Brickwork, and Which Type Do You Need?
Weep vents provide an outlet for water collected within a cavity wall. You will often see their narrow faces in the vertical mortar joints above doors and windows, where a cavity tray or lintel detail directs water towards the outside.
The small opening is deliberate. Pointing it up to make the brickwork look tidy can block the drainage route. If you are choosing replacements or ordering for new work, first establish which wall detail the vent serves.
Weep vent, weep hole or air brick?
A weep hole is an opening for drainage. A purpose-made weep vent forms that route with an insert, often including a grille. An air brick is a different product used within a ventilation arrangement, such as an underfloor system. Do not treat the names as interchangeable when buying.
The Timloc 1143 data sheet describes both water discharge and cavity ventilation. That does not mean a small wall weep can replace an air brick specified elsewhere in a building.
Built-in vents and retrofit drill vents
| Situation | What to check |
|---|---|
| New brickwork or a specified cavity tray detail | A built-in weep matched to the wall thickness and drainage arrangement |
| Discreet outlet wanted | The specified concealed weep system and any required extension |
| Existing wall needing a retrofit outlet | A suitable drill vent, with a professional assessment of the wall and drainage path |
Buying a retrofit vent does not establish where it is safe or useful to drill. An outlet needs to meet the water-collection detail inside the wall; making a hole in the outer leaf at an arbitrary height will not create a complete cavity drainage system.
What size is a Timloc 1143?
The standard unit is 65mm high, 10mm wide and 100mm long. The narrow face sits in the vertical joint. Check the length through the outer leaf, the colour required and whether the specified system needs an extension. Timloc also makes the 1144 extension piece; it is a component of that system rather than a universal extension for every vent.
Our range includes Timloc 1143 weep vents, Invisiweep wall weeps and retrofit drill vents. Check the selected colour and pack quantity on each product page.
How many do I need?
Use the set-out on the project drawings and the current instructions for the chosen system. Timloc’s 1143 installation guidance uses 450mm centres and its specification text calls for at least two weep holes over openings. Confirm how those requirements apply to your particular detail before calculating the order.
Count the required outlets first, then work out the packs. A box of 50 is a supply quantity, not a recommendation to put 50 vents into every wall.
Keep the drainage route clear
Mortar can block the back of an insert as well as its visible front. The vent must connect with the drainage detail, and remain clear during construction and later pointing. Persistent damp needs an assessment of the cause; a new vent on its own is not a diagnosis or a guaranteed repair.
Compare colours, lengths and installation types in our wall weeps and vents collection.
