Primer is a rather specific material. And not all customers understand what it is and what it is used for. This issue is very multifaceted and we can talk about it for a very long time. In this article, we will try to focus on the most important aspects of the issue of using primer during repairs of apartments and houses in Portugal.
So. It is necessary to distinguish between three main types of primers used during repairs:
- primer-paint
- deep penetration primer
- primer "concrete-contact"
Types of primer:
Primer-paint is applied to the already putty and sanded surface to ensure a more uniform application of paint to the surface. The fact is that if you apply paint to the putty without a primer, it will not hold securely and will not be applied very evenly. In some places, certain darkening is possible. This primer is also used when repainting walls and ceilings in an apartment or house from one color to another. If you do not plan to change the color, then it is enough to simply sand off small bumps, blackening, dust, etc. with a grinder and if the walls were previously painted with good paint, then you can repaint without priming. But often in Portugal we come across apartments painted with not the best paint, which is also applied unevenly. Sometimes it is better to re-putty such walls before repainting.
In Portugal, we can often see that before wallpapering, builders also use this primer-paint. But for the highest quality gluing, we recommend using another primer - deep penetration primer.
Deep penetration primer is perhaps the most common primer used during finishing works. The main function of this primer is to ensure adhesion between materials. In simple terms, it is needed to ensure that one layer of plaster or putty does not fall off from another layer that is underneath. And this is very important. So, you have probably seen how the putty and paint under old windows swells up from the inside of the room. This happens because moisture constantly gets in and these places swell. After repairs from replacing windows, these places need to be re-puttied. But if you just take and scrape off the old putty, and then just apply a new one, then after it dries, it can fall off the old one. The thing is that the old one must first be primed. The primer penetrates into the old putty and kind of holds it together. It becomes hard and does not "dust off". The new material will adhere to such a surface better.
We recommend using deep penetration primer during the renovation of apartments and houses in Portugal for priming walls before plastering or puttying, for priming the floor before pouring a screed or self-leveling compound, for fixing the old putty that has already been applied, for other places to which some material needs to be added locally.
Unfortunately, in Portugal we very often encounter renovations in which such a primer is not used, which leads to constant problems with the materials peeling off from each other.Primer of the "concrete-contact" type. Such a primer is needed in order to prepare a smooth and hard surface with very high resistance (non-absorption of water) for the application of another material on it. As a rule, it is used over a smooth level or over glazed tiles so that the new material has a large contact area with the previous material and so that this surface is rougher. Then the adhesion is most durable.
