 Myself Supriya Pasnoor, working as an assistant professor in civil department from Walton Institute of Technology, Solapur. Today's class, we are going to discuss plastering. These are the learning outcomes. At the end of this session, students will be able to impart the knowledge of different types of the plastering and their comparison. Plastering is the process of covering the rough and uneven surfaces in the construction of the houses with a plastic material or to form an even surface or a regular surface. Plastic material, it is called as the plastic or the mortar. The materials which are used for the plastering are called as the ordinary cement plaster. So the materials which are used for the plastering are called as the ordinary cement, the admixtures, lime or the clay, the aggregates and the water. So let us see what is the objective of the plastering. The main objective of the plastering is to obtain a smooth surface, a regular and an even surface. It also preserves and protects the surface from catching of the dust. It gives a good look for the aesthetic purpose it is used. Also it is used to cover the porous materials of the masonry work to conceal the defective workmanship. So let us see what is the requirement of the good plastering. So it should be hard and durable, it should be cheap and at the same time economical. It should prevent the penetration by the moisture. It should give a good insulation against the sound and also high resistance to the fire. So the method of the plastering is carried out generally in the following types. Let us see how the method of plastering is done. The plastering should be applied in one or two coats. That is a single coat will be a thickness of 12 mm. So whenever we go for a cheaper type of the constriction or the inferior type of the constriction, the plastering may be done in one coat. And if you go for the ordinary type of the constriction, in that case the plastering can be done in the two coats. And for the superior type of the constriction, you can go for the plastering of three coats. It depends upon the type of the building and the type of the constriction depends. Now next we have the, after the, before applying the final coat of the cement, we can, we should go, we should see that the previous coat which is applied should almost be dry. And in plastering, actually plastering, in the plastering you can see that the plaster, it is put on the wall by throwing it with full force or it may be used by pressing it on the surface of the wall. So let us see, depending on that you have the various types of the plastering. First we have the lime plaster, second is the cement plaster, third is the mud plaster, and fourth is the waterproof plaster or the stucco plaster. So the lime plaster, this is called as the lime plaster because lime is used as a binding material in this type. And also lime plaster is somewhat, it is similar to the lime mortar, only the difference will be in the use rather than the composition. And lime plaster it is actually composed of the ordinary lime, the sand and the water. It is, next is the cement plaster. Here you can see that the cement plaster, it is, cement is used as a binding material in this type of the cement plaster. So it is called as the cement plaster. So here you can see that the cement plaster it is applied in a single coat and the thickness of this coat it should not exceed 12 mm, 15 mm and 20 mm. If the plaster, if the thickness of the plaster it exceeds 15 mm. In that case you go for a cement plaster thickness of 6 mm and even the cement mortar proportion should be of 1 is to 3 or 1 is to 4 depending upon the plastering, depending upon the surface where the plastering has to be done. Next we have the mud plaster. Here you can see that the mud plaster it is somewhat similar to that, similar to the lime plaster and the cement plaster. Here the plaster it is applied in the two coats. So the thickness of the one coat is 18 mm and the thickness of the second coat it is 6 mm. Next we have the stucco plaster. Stucco plaster it is a type of a decorative plaster which can be used for the exterior of the buildings and it is applied in the three coats for a fine finishing. The single coat it is the first coat or a single coat. First coat it is called as the scratching plaster. The second plaster it is called as the finer plaster or the brown plaster. Then the third coat it is called as the first coat, second coat and the third coat you have. The thickness of the plastering and the total overall thickness will be of 25 mm including this all type of the plasters. Let us see the comparison between the cement plaster and the lime plaster. So here you can see that the lime or the gypsum it is called. There are some of the parameters which we can differentiate between the cement plaster and the gypsum plaster. So the materials which are used for the cement plaster are the cement and the sand. And sometimes it is also bought ready made or mixed on the site itself. And here the material used is gypsum powder manufacturing next parameter. It can be manufactured on the site itself or sometimes in the factories whereas the gypsum powder has to be manufactured in the factory application area where it is applied. The cement plaster can be applied in the internal and the external walls whereas the gypsum powder has to be applied in the internal walls that is the ceilings and all. And here you can see that it can be applied in the kitchens and the balconies etc everywhere internal and the external and this cannot be applied in the wet areas. The standard package size for the cement plaster is 40 kg per bag whereas for the gypsum it is 25 kg per bag. And the compressive strength it is the most important factor to select the type of plaster to be used. First for the cement plaster we have the compressive strength as 3.5 to 7.5 MPa whereas for the gypsum it is 5 to 7 MPa and next parameter we have the minimum coat thickness. So for the cement plaster it is minimum it should be 10 mm whereas for the gypsum it should be 6 mm that is it should not be less than 6 mm. If the thickness is less than 6 mm it may peel off from the wall and also the curing time you can see that the curing for the cement plaster it should be 7 days in water that is the wet curing is required for this whereas for the gypsum you require air curing which will be of 24 hours. Next comparison between the cement plaster and the stucco plaster. So the parameters are the materials here you can see for the cement plaster it is cement and sand whereas for the stucco plaster it is Portland cement, lime and the sand. The application areas for the cement is internal and the external walls whereas the stucco plaster you have the application area is the external walls and the standard package size is for the cement plaster is 40 kg per bag and here you have for the stucco it is 25 kg per bag and the versatility it is more versatile and whereas the stucco plaster it is used for the dry walls. So here are some of the mcq's select the correct answer from the options given below the question is before plastering the surface has to be first you have option as rough second is smooth third is cemented fourth is watered the right answer is rough. Here comes the second question in plastering the first coat is called dash and its signal should be dash mm. So the first option is under coat 6 to 9, floating coat 6 to 9, floating coat 10 to 15 and the under coat 10 to 15 which is the right answer for that. The right answer is under coat 10 to 15 mm. These are the references. Thank you.