Plaster and drywall are two common materials used in construction for creating interior walls and ceilings. However, there is a distinct difference between plaster and drywall in terms of their composition, installation method, and characteristics.
What is the difference between plaster and drywall? Plaster is a wet mixture traditionally made of lime, sand, and water, whereas drywalls are panels made of gypsum sandwiched between thick paper sheets.
Key Areas Covered
1. What is Plaster
– Definition, Features
2. What is Drywall
– Definition, Features
3. Similarities Between Plaster and Drywall
– Outline of Common Features
4. Difference Between Plaster and Drywall
– Comparison of Key Differences
5. FAQ: Plaster and Drywall
– Frequently Asked Questions
Key Terms
Plaster, Drywall, Construction
What is Plaster
Traditional plaster, used for centuries in ceilings, relies on the transformation of calcium sulfate, a common mineral. One key ingredient is gypsum, often found in the form of gypsum plaster (calcium sulfate dihydrate, CaSO₄•2H₂O). A hydration reaction happens when gypsum is mixed with water.
Water molecules are incorporated into the crystal structure, causing the plaster to set and harden. This hardening process is exothermic, releasing heat.
Modern mixtures of plaster often contain lime, which has the chemical formula CaO. When lime is mixed with water it produces calcium hydroxide. This reacts with the gypsum, further strengthening the set plaster. To provide strength and bulk, sand is added to the mixture. It acts as an inert filter making the plaster not too brittle.
Once applied in a wet paste over a lath base (often wood or metal mesh), the plaster hardens into a smooth, fire-resistant surface. This property is used in the making of ceilings, which causes aesthetic beauty and gives protection from flames.
What is Drywall
Drywall’s main component is gypsum (calcium sulfate dihydrate, CaSO₄•2H₂O). This material is fire-resistant. Gypsum loses its water molecules at high temperatures, forming a fire-resistant layer of calcium sulfate. This dehydration process also absorbs heat, slowing the spread of flames. It also has sound insulation. The dense, porous structure of gypsum helps dampen sound waves, contributing to a quieter living space.
This mixture also contains paper and additives apart from gypsum. Thick paper facings on either side of the gypsum core provide strength and stability to the panel. These papers also provide bonding surfaces for joint compounds and paint.
Common additives used in drywall are glass or cellulose fibers, starch or glue, and mold inhibitors. Fibers improve strength, starch or glue enhances the bonding while mold inhibitors prevent mold growth in moisture areas.
There are different types of drywall: standard drywall which is for typical interior walls and ceilings, moisture-resistant drywall for kitchens and bathrooms and fire-resistant drywalls.
Similarities Between Plaster and Drywall
- Plaster and drywall use gypsum as their main component.
- Both plaster and drywall provide a smooth, finished surface for interior walls and ceilings.
Difference Between Plaster and Drywall
Definition
- Plaster is a multi-layered composite material traditionally made with lime, sand, and water, while drywall is a building material made of a gypsum plaster core sandwiched between two sheets of thick paper.
Installing
- Drywall is quicker and easier to install than plaster.
Strength
- Plaster is generally stronger and more durable than drywall.
Soundproofing
- Plaster generally has better soundproofing due to its solid mass.
Conclusion
Plaster and drywall are two prevalent materials for constructing interior walls and ceilings, each with distinct characteristics and benefits. Plaster, a traditional material made from a wet mixture of lime, sand, and water, has been used for centuries due to its durability and fire resistance. Drywall, on the other hand, consists of gypsum panels sandwiched between paper sheets, offering a quicker and easier installation process.
FAQ: Plaster and Drywall
1. What are the disadvantages of drywall?
Drywall panels are heavy, so they need special tools to lift and install. They can get damaged by water, which can lead to mold and other problems. In addition, drywall can easily get dented or damaged by bumps, meaning it often needs repairs.
2. Is drywall harmful to humans?
When compounds such as talc, calcite, mica, gypsum, silica, and even high-risk items such as mercury in drywalls are inhaled as particulate matter, humans can get upper respiratory conditions like lung cancer and asthma.
3. Why do people use plaster walls?
People use plaster walls because their thickness provides better energy efficiency, which offers superior thermal breaks compared to drywall. This helps maintain indoor temperatures more effectively and reduces heating and cooling costs.
4. What is brittle out of drywall and plaster?
Plaster is harder and more brittle than drywall. This is because drywall is made of gypsum plaster sandwiched between layers of paper, which can crack or break more easily upon impact or stress. Plaster, on the other hand, is a thicker and denser material applied in layers
5. Why do people plaster over drywall?
People plaster over drywall to create a smoother, more durable, and aesthetically pleasing finish. Plaster provides a high-quality, seamless look that can cover imperfections and joints in the drywall. Additionally, plaster can add an extra layer of soundproofing and insulation
Reference:
1. “Drywall.” Wikipedia. Wikipedia Foundation.
2. “Plaster.” Encyclopedia Britannica.
Image Courtesy:
1. “Crop man plastering wall at home” (CC0) via Pexels
2. “A contractor prepares a peice of drywall…” (Public Domain) via Picryl
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