If you notice a brown stain on your plaster walls, bubbles or flakes, it is likely that your plaster walls or ceilings have been damaged by water. Water damage usually causes streaks and stains on walls and ceilings that vary in color from dark yellow to brown. To repair water-damaged plaster walls, you must first assess the damage, repair the source of the damage, remove the old plaster, and apply a joint compound to repair the cracks. Using a cold chisel and ball hammer, remove the damaged plaster from the wall.
To fill in the missing plaster and level the wall, use several thin layers of joint compound. Start by mixing a small amount of compound and use a flexible joint knife to apply a first coat. Spread an approximately ¼ inch layer of mud over the area and then immediately re-coat it to remove excess with parallel movements from one side of the repair to the other. Pre-mixed putty compounds, which come in small tubs, work well for smaller holes or cracks.
Use a spatula to apply the material to all damaged areas. Wipe off excess with a damp cloth or sponge and allow to dry. If the product shrinks as it dries, apply another layer. For larger holes or cracks, it may be necessary to first apply a layer of fiberglass mesh tape to provide support.
Apply the patch to the tape. Before you start fixing the plaster, you must first determine what caused the water damage. Continuously letting the plaster get wet will allow water to seep into the inside of the wall, damaging the wood and other structures behind it. However, some stabilizations of plaster walls damaged by water can cause damage after several months or years after stabilizing them. Using a bucket of clean water and a sponge, wash the surrounding area as a final cleaning exercise, and then let the water-damaged plaster wall dry completely. Latex is fine for a topcoat over the primer, but it can bubble if applied directly to the previous water damage.
If the damage to your wall is excessive, call someone who knows how to repair plaster walls damaged by water. It is advisable to stabilize plaster walls immediately because water damage can make them fragile and damage them even more. Knowing how to repair water-damaged wall plaster will allow you to make home repairs at a lower price. The repair process on this page can be used to repair water damage to the surface layers of plasterboard walls and ceilings. Before starting repairs on walls or ceilings that have been damaged by water, locate and stop the source of the leak or you will repair the same damage very soon. It would be best if you looked for signs of water damage, such as peeling paint, water stains ranging from yellow to brown, fallen and peeling plaster and, in the worst case, mold.