How to Repair Plaster Problems

Plaster needs repairs from time to time. With the normal contractions and expansions of the house, hairline cracks can often form in the plaster work. Sometimes you get damage by bumping furniture into walls, scratching up against it by accident or by not catching that eagerly thrown football that should never have been played with inside the house. Hey, it happens, but someone’s gotta fix it. When you know the basics of how to repair plaster, you can keep on top of those little blemishes on your walls and maintain your home’s good condition.

Tiny holes

To repair plaster holes, those tiny, pesky pock marks, you’ll need a putty knife and a quantity of spackling compound. You can buy it in cans that are just the right size for small touching up jobs, which means no waste, less expense and you don’t have to wonder next time, where you put it!

Follow the instructions on the can, but basically, all you need to do is apply the compound with the putty knife as though you were filling gaps in frosting on a cake, only far less tasty! Allow to dry and keep an eye on it for shrinkage. If a slight indentation remains, you may need to apply another coat. Take some fine sandpaper and give the spot a light sand then finish with the appropriate primer and a lick of paint.

Missing plaster

Firstly, fill any holes with spackling compound using a spackle knife but don’t fill to flush with the wall. Leave about 1/8 of an inch. Next, using the edge of the knife, scratch the damp compound with crisscrosses. Once dry, add a leveling coat so that the wall is now flush again.

If you need to repair plaster in bigger patches, you’ll probably have to use an appropriately sized section of drywall. Cut it out to size then screw in place. You’ll still follow the two-stage compound application as described above, but this time, extend the spackle approximately two inches outside of the drywall area so that it covers the surrounding wall as well.

Use paper drywall reinforcement tape to set into the compound and with a trowel or spackle knife, smooth over the area. You must allow each coat of compound to dry before applying the next and feather each one over a larger area than the one before. Finally, when the compound is completely dry, use a pad or pole sander with very fine sandpaper to create a smooth finish.

Loose plaster

For whatever reason, you may have sections of loose plaster to repair. First step is to remove any chunks with your hands then go ahead and patch up the holes, using the technique described for missing plaster.

Hairline cracks

Repairing hairline cracks in plaster requires a little drywall reinforcement tape. First apply a thin coat of spackle along the crack then embed the tape into the compound before it dries. Smooth over with the knife then follow the ‘missing plaster’ instructions to complete.

Other important hints

    • Knowing how to repair plaster includes knowing how to do it safely and cautiously. It’s advisable to wear protection over your eyes and mouth, the latter so that you don’t ingest fine plaster dust.
    • Use the appropriate reinforcement tape to repair plaster walls as it will ensure long lasting results.
    • When preparing spackle compound, mix only what you need because it dries very hard, very quickly. Always keep your tools clean of the compound because once it dries, it’s very hard to clean off.
    • Don't use a household vacuum for plaster dust, which is so fine that it gets past filters and into the motor.