The easiest way to tell if a wall is load bearing is to check if it’s an exterior wall or if it runs perpendicular to the joists above and below it (or parallel to beams). Exterior walls are almost always load-bearing, and walls that run under beams or parallel to them are also usually load-bearing. There are exceptions to these rules, and walls that don’t fit into these categories can still be load-bearing. If you’re unsure, hire a structural engineer to look at your home to assess whether or not the wall is structural.

If your home’s foundation shifts slightly over time, any seams in the drywall represent the weakest point in the wall, leading to cracks. If your home has significant changes in temperature and humidity, this can cause the drywall to swell and contract slightly, causing a crack at the weak point of the seam. If your drywall installer did a poor job securing the panels to the wall studs, this could cause a weak layout and cracks in the seams.

You can take a few steps to save money on drywall installation, even when hiring a professional to do the bulk of the work for you. These ideas include the following:

• Buy the drywall and other materials yourself to avoid product markup and delivery fees

• Ask about discounts if you use the same company to tape, spackle, and paint

• Hire drywall professionals in the winter when demand is the lowest

• DIY as many parts of the project as possible, like replacing insulation and painting

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.