Why your paint peels off

Wednesday September 16 2020

Most of the times, it is believed walls crumble because of poor mixtures by the builders. Photo/Rachel Mabala.

By Roland D. Nasasira

No home owner builds their house and anticipate paint peeling off at a certain point. 
In fact, the only thing they expect to do on walls after is add a fresh coat of paint at a much later stage. Some redevelopments can be part of the plan, but they remain a long-term arrangement. 
But then paint starts peeling off.
Many people believe walls peel because the builders embezzled some of the material needed, though, the problem is bigger than that.

Inbuilt water pipe leakages
According to Daniel Kyeyune, a builder, paint peeling is attributed to a number of factors. The first observation is that when plumbers are not careful enough to tighten and properly seal the joints of the inbuilt water pipes within your walls before plastering, water may over time go through the plaster and eventually getsto the paint. 
“When the paint can no longer hold or keep the water, it starts swelling and begins to peel off,” he says.
When you softly touch these swellings, Kyeyune explains, you will reach the plaster layer. The paint may at times crack on its own and part of the sand that makes up the plaster will be seen dropping on the floor. 

Water leakages through tiles 
Water pipe leakages may not be the only cause for paint peel off, but also when the water penetrates the tiles. For instance, if your bathroom or kitchen wall tiles were not well laid with enough grout or tile hardener, and there are gaps, the water splashed on the wall when washing utensils or when bathing will overtime finds its way into the wall body. The tiles may not fall off but you will realise the paint peel off from the other side of the wall. When you knock on such tiles, you will feel as if there is a gap between the tile and the wall against which it was laid, a sign of the damaging effect of water.  

Poorly built foundation 
Ibrahim Kajjoba, an engineer says poorly built foundations are also a cause. For example, most builders will not plaster the foundation layer before casting the Damp Proof Course (DPC) because it is often buried. The DPC is a thick polythene bag material that is used to separate the foundation from the upper part of the house. 
Kajjoba advises that if the foundation wall is not plastered, sooner or later, underground water will move up the wall even if the damp proof course was cast. As a result, paint will start peeling off the wall, starting from the bottom. The more the water moves up the wall, the more the paint peels off. 

Weather factors 
In most cases, external plaster is directly painted if there are no other methods of external wall finishing such as use of stone slates or face bricks. This, Kajjoba explains, exposes the outer side of the wall to harsh weather elements such as rain. When it hits the wall for longer periods, the wall eventually soaks and retains water. With nowhere to go, the water in the wall slowly penetrates the wall body until it eventually impacts on the internal wall paint, causing it to peel off. 

Poor quality sand  
Kyeyune agrees with Kajjoba, reasoning that in sometimes, you may be quick to conclude that your wall paint is peeling off because you suspect that your builders did not mix the right cement to sand ratios yet it could be that you (site owner) bought poor quality sand. However, this is not to say that poor cement to sand mixtures ratios do not cause paint peel off. The recommended mixtures ought to be one bag of cement to two or three wheel barrows of sand.   
“Even if the builders got the cement to sand ratio mixture right but when the type of sand, especially the one used at plastering stage, was bad, it will over time still cause the paint to peel off. This is because certain sand types especially the one that retains water is not meant for plastering,” Kyeyune says.
Kyeyune advises that even after plastering, it is recommended to give the plaster ample time, normally between two to four weeks to dry before you can think of painting so that when the paint is applied, it sticks to the wall for longer periods.