adanny01:
This issue has continually bothered my mind.

Why do Nigerians plaster a wall then install tiles on it. I expect that the bare wall of the sandcrete blocks is rough enough (coarse gradation) and preferable to the almost smooth surface of the plaster (fine gradation).

I know that it is required that after plaster and before hardening, the plaster should be roughed up to prep the surface that will be tiled.

Isnt it a waste of effort and resources to plaster as the bare wall has more rough surface to hold the tile than the plastered surface?

I lived in a rented house were the landlord renovated his house built in 1994 to modern finishing. He introduced skirtings and tiled the building externally below the skirting. Few years down the line, the house became a gory sight as the tiles continue to break lose from the wall. The particular tile design was no longer available in the market for him to buy few packs and replace. He had only one option, remove all tiles and reinstall with new ones. Of course, the cost was an issue.

The point is, if the house wasnt plastered smooth before the remodelling, his tiles wouldnt have fallen off so soon. The old wall was just too smooth even after the tilers did some work in scratching the wall surface. The wall had been painted before which also contributed.

Therefore, for a new building, is it not better to tile directly on the blocks?

Mailthaddeus:


The kind of plastering done on a wall to be tilled is not to be smooth. It's to be very rough and the mortar will grip better to its surface compared to a mere sandcret block. Unfortunately, some builders allow their mason do smooth rendering on walls to be tiled and this will eventually cause d tiles to fall off in due time.

adanny01:


Recently, I have seen buildings with claddings but were not plastered prior. It is a total waste of money to plaster a wall then install cladding on it.

Remember, claddings don't stick to walls, it's rather fixed to walls. Fixing claddings directly to hollow block wall may not be a good idea, unless d hollows of those blocks are filled.

In the same vein, why do people waste money on rough plaster when the tiles can easily stick to the block wall.

remember the ratio of mix for plaster and blocks are different, blocks will fall of more than a roughly plastered wall. Do ur test and confirm.

I just thought of a way to test this. I will plaster a portion of a block wall then install a tile on the bare block wall and another on the plaster portion. Days later, I will check which needs more effort to remove. Of course, the quality of blocks will affect the tile on bare wall.