How does balcony drainage experience affect Bosaso builds?

Balcony drainage experience gaps in Bosaso matter because a balcony is a small roof that also has a door in it. When the crew has not built one before, the falls, the outlet and the door threshold get decided while the slab is being cast, and water then sits against the wall instead of running off. The repair is disruptive and often comes out of the same budget twice.

Why does balcony experience matter more in Bosaso?

Balcony work concentrates several trades into a small area. The structure, the screed, the waterproofing, the tiles, the outlet and the door frame all meet within a few square metres, and each one depends on the levels set by the one before.

A crew that has drained balconies before sets the outlet low, keeps the screed falling to it, and holds the finished floor at the door above the outside level so water cannot track inward. A crew without that experience can cast a flat slab, place the outlet high, and leave the tile bed thicker at the door than the drain. The balcony then holds a shallow pool after every rain.

The failure is quiet at first. Water sits, the screed softens, and salt-laden damp works into the render and the plaster around the door. On the coast the salt in the air and the humid periods can make that worse. Ask the municipal engineer's office what it knows about the site's exposure, and read the project specification for the falls and outlet details rather than accepting a site decision.

What does the gap do to the work?

The gap shows up as water backing into rooms long before anyone calls it a drainage problem. The first sign is usually a damp patch or bubbling paint on the inside face of the wall near the door, and pooling on the balcony after rain.

Three things tend to go wrong together:

• The fall is too shallow, so the water spreads instead of running to the outlet, and the ponding finds the weakest point in the waterproofing.
• The threshold is set level with or below the balcony floor, so any standing water has a direct path under the door.
• The outlet is undersized or partly blocked by tile adhesive, mortar or grout washed into it during finishing.

Each of these is cheap to fix before the slab is cast and expensive after. Confirm the general practice limits, such as minimum falls, threshold upstands and outlet sizing, against the project's specification or with the project engineer, because the correct figures belong to that design.

How do you check experience before the work starts?

Ask for built balconies, not for years in the trade. Experience shows in a finished balcony, and it can be walked.

Ask the proposed supervisor to name two or three balconies the crew drained, then visit one with a spirit level and a bucket of water. Look at what happens to the water, not at how neat the tiles are. Check the door threshold from both sides, and look at the wall inside the room for old damp marks. Ask the caretaker how often the balcony holds water after rain.

At the site meeting, ask for the crew's method: where the low point is, how the fall is checked before tiling, and how the outlet is protected during finishing. A crew with the experience answers with levels and sequence. If the answers stay general, ask whether a specialist can set the levels and inspect the balcony before the screed is cast. Write the inspection point into the programme so the concrete waits for it.

What to do next

Before the next balcony slab is cast, ask the builder to name two built balconies the crew drained and walk one with a spirit level and a bucket of water. Check the fall, the outlet and the door threshold, and compare what you see against the balcony detail in the project specification. Record the low point and the outlet position on the drawing while the formwork is still open.