Weep Holes & Ventilation

Every cavity wall needs a way to shed moisture — rain that penetrates the outer leaf, condensation that forms on cold surfaces, and water that collects above cavity trays and lintels. Weep holes provide that escape route, allowing water to drain safely out of the wall before it tracks inward and causes damp. At the same time, airbricks and underfloor vents keep air circulating beneath suspended floors and through cavity walls to prevent the stale, humid conditions that lead to timber rot, mould and structural decay.

Our range covers every ventilation requirement from discreet concealed weep vents that vanish into the mortar line, through to full-height drainage vents, non-combustible A1-rated vents for buildings over 11 m, telescopic underfloor ventilators and traditional clay and plastic airbricks. All products meet NHBC Standards and UK Building Regulations (Approved Documents B, C and F). Order before noon, spend £200 ex-VAT, and we’ll deliver free next working day.

Concealed Weep Holes

Concealed weep holes give you all the drainage performance of a traditional open weep vent without the visual clutter. The Timloc Invisiweep and Rytons Rytweep slide into the perpend joint, trim flush with the brickwork and leave only a tiny outlet visible — face dimensions of just 7 × 65 mm that virtually disappear in the mortar line.

The 4 mm internal drainage path meets the NHBC 3:1 water-drop test and provides the minimum 25 mm cavity penetration required by NHBC Chapter 6.1. Both brands are available in colour-matched options (clear, buff, red/terracotta, white) and extension tubes for rendered or wide-wall applications. Installation takes under 20 seconds per vent: push-fit body, clip-on baffle and a snap-off logo tab after pointing.

Non-Combustible Weep Holes

For buildings where any storey is above 18 m (11 m in Scotland), Regulation 7(2) requires external wall materials to be non-combustible. Our non-combustible weep holes meet this requirement with A1-rated metal construction. The Timloc A1 Invisiweep is diecast in fire-rated zinc with a two-part electroplated coating, and the Rytons Rytweep Metal A1 offers the same concealed aesthetic in a fire-rated metal body. Both pair with non-combustible extension tubes for wider cavities.

Full Height Weep Holes

Where greater drainage capacity is needed — parapet walls, wide cavity scenarios or locations with heavy driving rain — full height weep holes run a taller channel through the mortar joint to move more water. The Timloc 1143 Full Height Cavity Wall Weep is the standard choice, suitable for any situation where water must be discharged from an external wall: above lintels, within cavity tray systems, at ground floor slab level and in retaining wall applications.

Underfloor Vents

Suspended timber ground floors need cross-ventilation to prevent moisture build-up, condensation and timber rot. Our underfloor vents include the Timloc 1201 Telescopic Underfloor Ventilator, which adjusts between 3 and 5 brick courses and provides the free airflow area required by Approved Document C. An incorporated grille prevents vermin entry. Extension accessories — the 1203 Horizontal Front Extension and 1204 Vertical Extension Sleeve — accommodate different wall build-ups and ground-level conditions.

Airbricks

Airbricks are the visible face of your underfloor ventilation system. We stock the full range: kiln-fired Forterra Red Bank clay airbricks in terracotta, buff and blue-black for heritage and premium façades, and tough ABS Timloc plastic airbricks in black, grey, white, buff, brown and terracotta for modern builds. The standard 9 × 3 in (215 × 65 mm) size delivers around 7,250 mm² free area — sufficient for typical suspended-floor ventilation. Plastic airbricks clip directly onto Timloc telescopic underfloor vents for a sealed, draught-free connection.

Weep Vent Spacing: How Many Do You Need?

NHBC Standards and Approved Document C set the spacing requirements for both weep vents and airbricks. As a general rule, weep vents should be spaced every second brick (450 mm centres) above cavity trays, lintels and at DPC level, with a minimum of two vents per tray run or lintel. Airbricks should be spaced at no more than 2 m centres around the perimeter, within 450 mm of the end of any wall, and positioned at least 75 mm above external ground level.

For a detailed breakdown of spacing requirements, product selection and installation best practices, read our weep vent guide or call 0118 922 7941 for a free take-off against your drawings.

Related products: cavity trays — weep vents work in partnership with trays to drain moisture out of the wall.