Bastida Column Cap - Cover That Protects Against Rainwater
Bastida Column Cap: the cap that closes the post
An enclosure column is hollow and gets filled with mortar. Left uncapped, it collects rainwater like a cup: the water seeps in, freezes in winter, expands and opens up the joints between pieces. This cap prevents that with a Ø 28 × 4 cm cover that overhangs the Ø 22 cm shaft and has a drip edge at Ø 24.5 cm to release the water clear of the column.
✅ Key advantages
Keeps water out: the technical reason for the piece. Without it, the mortar fill becomes saturated and frost works against the joints.
Drip edge at Ø 24.5 cm: the water is cut off and falls to the ground instead of running down the shaft and leaving dark streaks.
3 cm overhang per side: the cap projects past the column's Ø 22 cm, so it also protects the edge of the last piece.
Finishes the fence: it's what separates a finished enclosure from an unfinished job. It gives each post a clean cap and a continuous horizontal line.
Matching finish: the same colours as the column, the panels and the panel coping.
One-minute installation: one piece per column, bonded with mortar or tile adhesive.
🏗️ Recommended applications
Capping the posts of plot and house enclosures.
Capping the pillars of dividing fences between neighbours.
Finishing columns on extensions built up on existing walls.
Capping columns in enclosures for pools, vegetable gardens or play areas.
📋 Technical data sheet
Material: precast concrete.
Dimensions: Ø 28 × 4 cm.
Distance between drip points: Ø 24.5 cm.
Weight: 5.22 kg per unit.
Pallet: 30 units, 172 kg.
Coverage: 1 piece per column.
Colours: white, anthracite and sand.
Use: outdoor.
🧩 This cap is one piece of a system
It's the last of the four pieces in a modular enclosure that's installed together. You'll also need:
The Bastida multi-angle column (Ø 22 × 17.1 cm): the post this cap sits on. It's stacked at 6 pieces per metre of height, and its toothed profile lets the enclosure turn at 45º, 90º, 135º, 180º and 225º, for corners, kinks and sloping ground.
The Bastida enclosure panels (75 × 11 × 12.5 cm, straight or curved): fill the bay between columns, at 10.70 pieces per m².
The Bastida panel coping (50 × 20 × 4 cm): caps the last panel course, at 2 pieces per linear metre, and its starter piece fits into the column's toothed profile.
How many you need. One per column, no more, no less. As a reference: a 3.00 m bay between columns is closed with 4 panels per course and a 3.75 m one with 5; with 15 courses the fence reaches 1.88 m and with 19 courses, 2.38 m, reducing the bay to 3.00 m. Count the columns in your layout, add one for every corner and every end, and that's how many caps you need.
🧰 Installation
Screed the last piece. Before capping, fill the column with lean M-40 mortar and screed it level with the top edge of the last piece, so there's no hollow where water can collect.
Wait for curing. Water the work for 2 days and let it dry for at least a further 48 hours before capping.
Wet the piece. Dampen the cap so it doesn't draw water out of the bonding mortar.
Centre and bond. Bed the cap with mortar or tile adhesive, centred on the shaft so the overhang is even all the way round.
Check the level. Check with a spirit level that it's horizontal in both directions: a tilted cap concentrates water at one point.
Clean and protect. Remove mortar residue before it sets and, once dry, apply a surface water repellent. No acids or high-pressure water.
📦 Available formats
Column cap Ø 28 × 4 cm — single unit.
Column cap Ø 28 × 4 cm — pallet of 30 units (172 kg).
Colours: white, anthracite and sand.
💡 Professional tip: a lot of people leave the column caps "for later" because they look like pure decoration and the budget is tight. It's the saving that costs the most: the uncapped hollow column fills with water, the fill mortar becomes saturated, and at the first freeze-thaw cycle the joints between pieces start to open and leach white efflorescence. Fixing it means dismantling the column from the top. Fit them during the same job. And when bedding them, don't hammer them into place: they're 4 cm-thick pieces with a recessed drip edge on the underside, and a sharp knock splits them right along it. Bed them by hand and adjust with a rubber mallet.
