Figuring out the necessity of plastering for the doors and windows is not easy unless the damages are quite important. You should spot them and do all the calculations accordingly. You will use them the moment you will choose the plastering materials. Spruce lath is used (in plastering) in dimensions of 1/4 x 11/2 inches and 4 foot in length. If you would like to cover 100 square yards then you need nearly 1500 laths.
Usually plaster is done in three coats: scratch, brown and white coats. There are several types of plastering methods varying on the use of lime or gypsum. Gypsum will harden more quickly than the lime but you have to follow the instructions suggested by the manufacturers. Nowadays, plaster boards and metal laths are used instead of wood lath. Although they are expensive, they do reduce the risks of fire. However, you can use any methods but keep in mind that plaster need to be done on baseboards as the open spaces can easily catch fire.
Many people plaster a concrete wall to change its appearance and to make it more resistant to moisture. Plastering a concrete wall is a lengthy process. First, you need to build the wall, then to allow it to cure and to dry. You should keep in mind that a concrete wall should be well built because a badly-prepared surface will crack and the plaster will come out of the wall. Walls with old paint, or dirt, or even mold formations will also cause problems.
You can follow the following techniques to plaster a concrete wall:
• First build a strong concrete wall. If you have painted it and the paint is cracking and peeling, then you need to remove the whole paint from the wall or simply to sandblast it.
• If you are not sandblasting the wall, set up a metal lath over the painted concrete. In order to attach the metal lath to the wall, you can use concrete screws and washers of 7/8 inch, separated 12 inches apart.
• Caulk the breaks. Treat any mold formations and remove the stains left them. Clean the cement joints by using a wire brush. You can use the bonding to remove any paint securely bonded to the wall. Then apply a slurry coat to the wall and to get the flat finish: use a consistently liquid slurry.
• After that, mix the plaster as instructed by the manufacturer. Apply it. You can then smooth the plaster to get a flat wall.
If you would like to finish the work more quickly, you can use gypsum board commonly available in the market. It requires no plastering and it is ready for paper or paint. Paper is recommended as the paint is not useful to hide the joints. The gypsum board is 3/8 inch thick. Whereas the others laths and plasters are 7/8 inch in thickness. Also one main advantage of using the gypsum board is there will be no wastage while applying it.
Gypsum boards cost much higher than other laths or plasters but this is the most preferable way of plastering. Although it is expensive, it greatly reduces the labour cost.