In brief
- A training certificate records attendance, not the ability to spread a bed that gives full contact under a floor tile.
- Hollow floor tiles show up as a dull sound when tapped and as grout lines that crack, because the bed never touched the tile.
- Ask for the assessment method, the batch record for the bedding mix and permission to lift one tile before accepting handover.
Contents
Attendance at a tile bedding course in Hargeisa does not prove that a tiler can spread a full bed under each tile. A certificate shows someone sat in a room. Competence shows in the bed itself: how the mortar is mixed, how far the notched trowel is held, whether the tile is pressed and twisted into contact, and whether anyone checked the finished floor before it was grouted.
What does tile bedding training actually test in Hargeisa?
Most short courses test recall, not hand skill. A tiler can name the right mortar ratio and still leave voids under half the tiles he lays. Assessment by written paper or by watching a single demonstration tile tells the trainer very little about a full day of production.
The gap widens when the course has no wet bay where each trainee lays a run of tiles and has them lifted the next day. Practical assessment needs a fixed surface, a measured mix, a set area to cover, and an inspection of the bed after lifting. If the training provider cannot describe that routine, ask what the practical pass test is and who signs it off. A supervisor hiring from the course can run the same test on site: give the tiler a small bay, let it cure, then lift one tile and look at the back.
Why do hollow floor tiles appear after handover?
The bed fails before the tile does. Thin bed mortar relies on full contact between the tile back and a ribbed mortar layer. Hold the trowel at too steep an angle and the ribs flatten; skip the back-buttering of a large tile and the corners bridge. The tile sits level and looks right. Underfoot, the void rings hollow when tapped.
Once grout locks the edges, the tile cannot move, so the movement goes into the grout and the tile itself. A hollow tile near a doorway or in a kitchen takes concentrated loads and can crack. Water that reaches a void through a joint has nowhere to drain. Floors that swing between hot days and cool nights work the assembly, and a weak bed has less capacity to absorb that movement. Measure the floor's daily temperature movement on your own site rather than assuming a figure. None of this proves a defect is widespread in the city. It is the mechanism to check on the floor in front of you.
How does a supervisor catch a weak bed before grouting?
Tap testing is the first check and it happens before grouting. Walk the floor with a light hammer or a screwdriver handle and tap every tile, especially corners and cut edges. A hollow note marks a void. Mark the tile, lift it while the mortar is still green if the specification allows, and inspect the bed and the tile back for coverage.
Before that, check three records. Ask for the bedding mix proportions and the batch the tiler actually used, not the one on the bag. Watch the trowel angle and the notch depth against the project specification. Confirm the tiler back-buttered large format tiles. The engineer or clerk of works should state the acceptance rule for hollow spots in writing before work starts, because limits vary between specifications. A defective tile can be lifted and relaid if it is caught early.
What to do next
Ask the training provider for the practical pass test in writing, including how many tiles each trainee lays and who inspects the bed. On site, tap test a completed bay before grouting and have one tile lifted in the presence of the tiler and the clerk of works. Photograph the bed and the tile back. Fix the first bay before the rest of the floor is laid.
Frequently asked questions
Does a tiling certificate prove a tiler is competent?
No. A certificate records attendance and, at best, a written pass. Competence shows in the bed under a finished tile, so ask the provider what practical test was used and inspect a lifted tile on site before accepting the work.
Can I fix hollow tiles after they are grouted?
It is harder. Grout locks the edges, so lifting a hollow tile later risks damage to neighbouring tiles. Catch hollow spots by tapping before grouting, and agree with the engineer or clerk of works on which tiles may be lifted and relaid.
Local reporting: this article is written for building work in Hargeisa and Somaliland. Ground conditions, prices and rules differ between places; confirm the details for your own site.