Small cracks often appear in plaster walls and ceilings, usually these are nothing to worry about but it is always worth knowing the signs which may indicate something serious and when professional advice should be sort. For cracks in walls the cracks are generally: • Small (up to 2mm) cracks taking random directions, these are probably just 'drying out' cracks and do not usually indicate any problems with the basic structure. • Cracks which go in definite horizontal or vertical straight lines, or which go in a stepped pattern could indicate something more serious and a professional assessment should be obtained. • Any long cracks wider than about 3 mm, or where something thin can be pushed deep into the crack may again suggest professional assessment is obtained. In some older properties, the joints of plasterboard used for ceilings was sometimes not 'taped' before they were skimmed with plaster and this can lead to cracks where adjacent sheets meet. These cracks can often look quite bad as they can cover quite large areas. These cracks are not usually structural and can be hard to cover.

Most small cracks will easily be covered by normal wallpaper but when walls or ceilings are to be painted with ordinary paint, the cracks will need to be filled before painting and this article deals with filling small cracks for this purpose. Repairing cracks Small cracks in plaster should first be widened so that filler can be pushed right in and has something to key on to. The corner of a scraper or filling knife is ideal for removing any loose plaster and for opening up and deepening the crack.

Try to undercut the crack with the corner of the scraper to give a better key for the filler. Using a dry paint brush brush along the line of the crack to remove any loose dust and dirt. Mix a quantity of filler as per the manufacturer's instructions and before applying it, dampen (but don't soak) the inside of the crack using a small paint brush dipped in clean water.

Use a filling knife to apply the filler along the line of the crack and press the filler into it - leave the filler proud of the surrounding surface. Dip a clean filling knife in clean water and run it along the line of the crack to level the filler to the surface around it. Fillers for this type of work usually shrink as they harden, and so after the filler has hardened, the filler within the crack may need to be built up using a number of applications.

Apr 10, 2012. Spackling's best use is to fill holes made by pictures, curtain holders, etc. To fix cracks in plaster, use Plaster of Paris or Durabond, not spackling compound. Cracks are caused by moving or shifting, so one needs to make sure the existing plaster and corresponding substrate (in this case the lath) are solid. Plaster walls can crack from time to time. We'll show you how to plaster over a crack properly. You will learn how to prepare a crack before you plaster, and the best way to reinforce new plaster with jointing tape. Continue to step-by-step instructions.

Between each application of filler, the surrounding surface should be lightly sanded and moistened before applying the next application. Repairing chipped plaster corners The modern technique for plastering external corners usually incorporates a metal corner strip which generally protects then from damage. Toshiba Tecra A3 Audio Drivers Download. However, in older properties external plastered corners were often just render and plaster and the corners can be chipped away by knocks and scrapes. Repairing such damage can be easily be carried out using a suitable plaster filler. Start by brushing the area of damage to clean off any loose dust and dirt.

Use a moistened paint brush or water spray to dampen the area of damage (but don't soak the plaster). Using a wide bladed filler knife, apply some filler to the damaged area, work the filler into the damage and make sure that there are no voids in the filler being applied. Run the filler knife up and down the surrounding plaster on both sides of the corner to get the filler level with the sides. When the filler begins to harden, use a wet finger to form the corner of the repaired area to the profile above and below - external corners are rarely sharp edged, often they are slightly rounded.

The filler used in the repair may shrink as it hardens, so the surface of the repair may need to be built up using several applications of filler. Between each application, lightly sand the area of the repair and the surrounding surface and moisten the surface before applying some more filler.

2 Blow out the plaster dust. Using a medium-bristle brush, scrub the area with a solution of water and tri-sodium phosphate (TSP) or a non-phosphate detergent. 3 Cut short pieces of self-adhesive fiberglass mesh joint tape and cover the groove with them. 4 Dip a sponge in clean water and dampen the area.

5 Mix setting-type joint compound and apply it over the tape and groove using a 3-inch-wide putty knife. Smooth it out evenly and allow it to dry. 6 Apply another coat of joint compound with a drywall knife or wide-blade putty knife. Apply it smoothly and “feather” the edges so that they taper into the undamaged area. Allow the compound to dry and then sand lightly to blend the patch into the wall at the edges. 7 Prime with a high-quality latex primer and then paint. ©HomeTips Using a nail, score the plaster and then apply spackling compound to it.

Repairing Large Cracks in Plaster Larger cracks can be fixed in a similar way: 1 Widen the crack with the can opener and dampen the edges of the crack with a sponge. 2 Fill the crack half full with patching plaster. When it has dried a little, score the plaster with a nail, as shown at right. This will give the next layer of plaster something to hold onto. 3 Dampen the patch again and apply another layer of patching plaster to about 1/4 inch of the surface. Ambe Codec Softwares. Let the patch dry and apply a coat of finishing plaster. Repairing Holes in Plaster It’s relatively easy to repair small holes in plaster if the lath backing that grips the plaster is intact.

If the lath backing is fine, you can mix joint compound with plaster of Paris for the patch. First brush away loose plaster and dust. Working from the edges inward, push the plaster mixture into and through the lath for a good bond. Apply an initial “scratch” coat. Let this dry, then apply a finish coat. If there isn’t proper backing behind the hole, install backing first.

Begin by enlarging the hole just enough to expose firm lath around the perimeter. Using tin snips, cut a piece of wire mesh that’s large enough to bunch-up and fill the opening when you push it into the hole.

If necessary, wind wire ties wound around one or two dowels or sticks to hold it in place until the plaster mixture hardens. Apply the plaster mixture in layers, allowing each to set before applying the next. When the patch is complete, and dry, just snip off the exposed wire. Getting the surface coat smooth can be tricky, especially if the hole is large and you have limited plastering skills. In this case, use only joint compound for the final coat.

When the patch is dry, use fine sandpaper to sand the surface smooth. Then prime and paint it to match the wall. How to Fix Sagging Plaster Flaking and cracking plaster are relatively minor repair items, but when the plaster starts to sag, or “belly out,” from a wall or ceiling, it indicates deeper problems. Plaster is heavy, and it needs a solid, well-anchored base to support its weight. This base is usually strips of wood or metal wire mesh (both referred to as lath) that are nailed to the wall and ceiling framing.

When the plaster is applied, it squeezes through the lath, creating “keys” that harden to form a strong integral bond with the wall. Over the years, plaster can dry out and lose its holding strength, or weaken from vibration, and the keys begin to break away. The lath can also pull away from the framing. Gravity and the weight of the plaster exert themselves, and the first sign is often sagging, followed eventually by the collapse of the plaster surface. At this point, you may want to call in a professional. Repairing a large wall area is difficult enough, but if the ceiling is beginning to sag, working over your head with heavy, hard-to-handle materials is not an easy job. If you still want to attempt your own repairs, here’s how: 1 First, protect the flooring under your work area, because once you begin the entire affected area could give way.

To prevent plaster dust from spreading into the rest of the house, hang damp sheets or tape plastic sheeting over the doorways and put an exhaust fan in a window. If you’re worried that much of the ceiling could come down at once, build T-shaped supports from 2 by 4s and use them to hold a piece of plywood flat against the ceiling while you work. 2 Use a hammer and cold chisel or wrecking bar to chip out a small area at the edge of the bulge (wear safety glasses). Once you can see behind the surface, you should be able to tell if the plaster has pulled away from the lath or the lath itself has come loose from the framing.

If the lath has pulled away and the plaster is still well-adhered to it, you may be able to refasten the lath to the framing without removing the plaster. 3 Use long drywall screws that will penetrate at least half their length into the wood framing.

Start near the edge of the bulge and press the ceiling upward as you drive the screws (you may have to shift your plywood support, and the tees holding it, as you work). Because the plaster and lath form an integral sheet, like a piece of drywall, it may go back up without a problem. However, if the lath has warped, or if the old nails in the framing prevent the lath from returning to its original position, this may prove impossible. You might have to first remove much or all of the plaster just to get the lath back up. Note: Please see the reader comment at the bottom of this page for a method of reattaching sagging ceilings using drilled holes along the crack line on both sides. 4 If the lath is still anchored to the ceiling joists and the plaster has pulled away, your only option is to remove the old plaster. It’s a dirty job, but if there’s nothing holding the plaster to the framing, it will come down quickly.