Popular wall textures include orange peel, knockdown, spray sand, and smooth finishes. Orange peel and knockdown are particularly common choices for drywall as they are simple and cost-effective. Orange peel texture has a lightly bumpy surface resembling the skin of an orange, while knockdown (sometimes called knockout) looks like a stucco finish with flattened high spots. In contrast, popcorn texture has fallen out of fashion, partly due to its past association with asbestos and a shift toward more restrained interior design styles.

All plaster walls will crack over time due to normal house settling and expansion and contraction from temperature and moisture changes. Small, thin hairline cracks are generally not serious and are mostly a cosmetic issue. However, larger or more significant cracks can indicate structural problems.

Here's how to tell the difference:

• Cosmetic Cracks: Cracks that are 0.5 cm (0.2 inches) or thinner are typically cosmetic.

• Structural Cracks: Cracks wider than 0.5 cm, excessive or deep cracks, multiple cracks in the same area, or cracks that span around corners can signify a structural or foundation issue. Cracks along the joints where walls meet the ceiling also warrant attention.

For cracks wider than 0.5 cm, structural repair is needed. If a crack is 2.5 cm (1 inch) or wider, or if you notice any signs of a structural problem, it is best to contact a plaster repair professional to assess the damage.

Plastering lasts for around 15 to 20 years without needing repairs or maintenance in most cases, and with proper upkeep, plastering can last a lifetime—sometimes more than 100 years. Plaster repair costs between $1 and $3 per square foot, and you may need these services once every 15 to 20 years or so unless you have a harsh climate where humidity changes are a constant issue. You can also opt to skim-coat plaster for between $0.90 and $1.30 per square foot, which may serve you better in the long run.

A 50-pound mirror can be hung on drywall, but only if it has the support of strong hardware. Ideally, you can find the studs behind the drywall and attach the mirror to them; this will give your mirror better stability. Otherwise, confirm that you are using anchors appropriate to the weight of the mirrors. Another technique is to use French cleats—two pieces of wood that fit together, with one piece attached to the wall and the other to the mirror. This allows the weight to be distributed over a wider area.