When you decide to paint, your expectation is that the paint will automatically stick on the plaster, however that may not be necessarily the case because of a few reasons listed below
The wall is not clean
On most occasions it is because of the wall surface condition, this may be a result of inadequate preparation before deciding to paint, if your wall is not clean this means that you have not removed residual oils, grease, waxes, and dirt making the surface lack an abrasive to allow whichever paint you are using to grip.
when you clean the surface before painting it also ensures that you have an easy time while working. you may take less time to paint than you could if your surface was dirty.
cleaning the wall will mild soap and water, then allowing it to dry ensure there is adhesion when painting.
You are using latex paint over oil-based
For instance, if you are using a primer that is latex or water-based and the paint you are using is oil-based, they both would not stick and you will have wasted your time and finances too.
Any type of latex paint can be applied over oil-based primers, however, a surface primed using an oil-based primer could be too smooth for latex paint to adhere to, for this reason, it is advisable to use a heavy-duty primer first for you to be successful in what you are doing.
Although oil-based primers have a strong scent that could be harmful to someone working without a mask, it is the best since it sticks faster compared to water-based.
When the coat of oil-based has dried, and there is no more oil on the surface it becomes appropriate for the water-based coat to be applied since the surface is not oily and it can easily adhere to the plaster.
Too little paint on your roller
This may cause paint to easily peel since it does not have a strong foundation. If it is applied to a damp surface or the siding that is less than six-inch above the ground. when the quantity is not right then the outcome will automatically be a mess.
It may also cause blisters since it was not applied in the right quantity, it makes it easier for moisture to pass through the walls, using a little paint in direct and intense light can cause heat bubbles to easily occur on the exterior.
Therefore knowing the right quantity that should be on a roller is important if you want an outcome that is desirable.
Too much paint on your roller
When painting your focus should be on the sucking sound as you push or pull the roller, if you can hear it at the beginning then it means you have too much paint.
too much paint may easily cause bumps on the wall which can peel easily at the slightest provocation.
there are dried-up drips on the wall which happens typically when the paint is too thick and commonly occurs at the top and bottom of the wall.
Also, the uneven distribution of paint may be a result of too much paint on the roller. this is because it might be difficult to balance when painting. it can easily cause crack
The lines around outlets are messy
It is important to remove the switch and outlet covers before you begin painting this will allow you to use the roller to get closer to the outlet and prevent you from cutting in with a brush.
The type of roller or brush that you are using
Using the correct tool while painting does not only make your work easier but also ensures that you get the best result which involves paint sticking on the plaster.
For you to achieve painting in such a way that the layer is laid on the surface gently and evenly. it is better to choose a paintbrush with split ends whose fiber is elastic and can not break when pressed.
It is also better to perform painting work with brushes that have a length of bristles at least one and half times as long as the width. and also remember to clean the brush before using them.
Knowing that a roller is often used to work with stencils is important information that should never be ignored.
To sum up
The wall being tired of painting and just wanting to be left alone is also a reason.
Sometimes it is because the wall is tired to be painted, this may be because the wall
is too old and has not been maintained for a long period of time. it may also be because it has a lot of cracks and holes that need to be repaired hence making the paint not stick.
It being tired means it is not in the right condition to be painted and needs some repairing before you paint it.