Plaster vs. Screed — What's the Difference?

Fireproofing or soundproofing walls.

For underfloor heating or insulation.

For patching walls and ceilings.

Laid on a damp-proof membrane.

Used in mold making and sculptures.

A liquid formula that spreads easily.

Aesthetic coatings for interiors.

Directly applied to a concrete base.

Smooth finish over plasterboard or undercoats.

Added fibers improve strength.

Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications.

Screed has three meanings in building construction: a flat board (screed board, floating screed) or a purpose-made aluminium tool used to smooth and to "true" materials like concrete, stucco and plaster after they have been placed on a surface or to assist in flattening; a strip of plaster or wood applied to a surface to act as a guide for a screed tool (screed rail, screed strip, screed batten); the material itself which has been flattened with a screed (screed coat). In the UK, screed has also come to describe a thin, top layer of material (sand and cement, magnesite or calcium sulphate), poured in situ on top of the structural concrete or insulation, on top of which other finishing materials can be applied, or the structural material can be left bare to achieve a raw effect.

A mixture of lime or gypsum, sand, and water, sometimes with fiber added, that hardens to a smooth solid and is used for coating walls and ceilings.

A long monotonous speech or piece of writing.

Plaster of Paris.

A strip of wood, plaster, or metal placed on a wall or pavement as a guide for the even application of plaster or concrete.

A pastelike mixture applied to a part of the body for healing or cosmetic purposes.

A layer or strip of material used to level off a horizontal surface such as a floor.

Chiefly British An adhesive bandage.

A smooth final surface of a substance, such as concrete, applied to a floor.

To cover, coat, or repair with plaster.

A piece or narrow strip cut or torn off from a larger whole; a shred.

To cover or hide with or as if with a coat of plaster

A piece of land, especially one that is narrow.

To apply a plaster to

A rent, a tear.

To cover conspicuously, as with things pasted on; overspread

A piece of writing (such as an article, letter, or list) or a speech, especially if long.

To affix conspicuously, usually with a paste

(by extension) A speech or piece of writing which contains angry and extended criticism.

To make smooth by applying a sticky substance

Chiefly in the plural form screeds: a large quantity.

To make adhere to another surface

Senses relating to building construction and masonry.

To inflict heavy damage or injury on.

A tool, usually a long strip of wood or other material, placed on a floor to be covered with concrete, a wall to be plastered, etc., as a guide for producing a smooth, flat surface.

To defeat decisively.

A tool such as a long strip of wood or other material which is drawn over a wet layer of concrete, plaster, etc., to make it smooth and flat; also, a machine that achieves this effect; a screeder.

To apply plaster.

A smooth, flat layer of concrete, plaster, or similar material, especially if acting as a base for paving stones, tiles, wooden planks, etc.

(uncountable) A paste applied to the skin for healing or cosmetic purposes.

A (discordant) sound or tune played on bagpipes, a fiddle, or a pipe.

A small adhesive bandage to cover a minor wound; a sticking plaster.

The sound of something scratching or tearing.

(uncountable) A mixture of lime or gypsum, sand, and water, sometimes with the addition of fibres, that hardens to a smooth solid and is used for coating walls and ceilings; render, stucco.

To rend, to shred, to tear.

(countable) A cast made of plaster of Paris and gauze; a plaster cast.

To read or repeat from memory fluently or glibly; to reel off.

(uncountable) plaster of Paris.

To use a screed to produce a smooth, flat surface of concrete, plaster, or similar material; also (generally) to put down a layer of concrete, plaster, etc.

(transitive) To cover or coat something with plaster; to render.

To become rent or torn.

(transitive) To apply a plaster to.

To play bagpipes, a fiddle, or a pipe.

(transitive) To smear with some viscous or liquid substance.

(intransitive) To make a discordant or harsh scratching or tearing sound.

(transitive) To hide or cover up, as if with plaster; to cover thickly.

To play (a sound or tune) on bagpipes, a fiddle, or a pipe.

To bombard heavily or overwhelmingly; to overwhelm with (weapons) fire.

Strewn with scree.

To smooth over.

A strip of plaster of the thickness proposed for the coat, applied to the wall at intervals of four or five feet, as a guide.

An external application of a consistency harder than ointment, prepared for use by spreading it on linen, leather, silk, or other material. It is adhesive at the ordinary temperature of the body, and is used, according to its composition, to produce a medicinal effect, to bind parts together, etc.; as, a porous plaster; sticking plaster.

A fragment; a portion; a shred.

A composition of lime, water, and sand, with or without hair as a bond, for coating walls, ceilings, and partitions of houses. See Mortar.

A breach or rent; a breaking forth into a loud, shrill sound; as, martial screeds.

Calcined gypsum, or plaster of Paris, especially when ground, as used for making ornaments, figures, moldings, etc.; or calcined gypsum used as a fertilizer.

An harangue; a long tirade on any subject.

To cover with a plaster, as a wound or sore.

A long monotonous harangue

To overlay or cover with plaster, as the ceilings and walls of a house.

A long piece of writing

Fig.: To smooth over; to cover or conceal the defects of; to hide, as with a covering of plaster.

An accurately levelled strip of material placed on a wall or floor as guide for the even application of plaster or concrete

A mixture of lime or gypsum with sand and water; hardens into a smooth solid; used to cover walls and ceilings

Any of several gypsum cements; a white powder (a form of calcium sulphate) that forms a paste when mixed with water and hardens into a solid; used in making molds and sculptures and casts for broken limbs

A medical dressing consisting of a soft heated mass of meal or clay that is spread on a cloth and applied to the skin to treat inflamed areas or improve circulation etc.

A hardened surface of plaster (as on a wall or ceiling);

Adhesive tape used in dressing wounds

Cover conspicuously, as by pasting something on;

Affix conspicuously;

Apply a plaster cast to;

Apply a heavy coat to

Coat with plaster;

Dress by covering with a therapeutic substance

Plaster is used for coating walls and ceilings, while screed is used to level and prepare floor bases.

While typically a base layer, some screeds, especially decorative or polished screed, can serve as the final floor surface.

Drying times vary depending on the type of screed, thickness, and environmental conditions, often ranging from a few days to several weeks.

Fibers increase the tensile strength of the screed, helping to prevent cracks and enhance durability.

Typically, plaster is not suitable for floors due to its composition and durability requirements; screed is designed for floor use.

Its fluid nature allows it to spread out evenly over the floor surface, reducing labor and ensuring a level finish.

Screed is often necessary to ensure a level and solid base for various floor coverings, though some installations may not require it.

Gypsum plaster provides a smooth finish, dries quickly, and has good fire resistance, making it popular for interior applications.

Costs vary based on material types, application complexity, and project scale, with some plasters and screeds being more expensive due to specialized properties.

Certain plasters can improve thermal and sound insulation as part of their composition and application thickness.

Plastered surfaces may require occasional repairs and repainting, while screeded floors, especially if used as the final surface, need sealing and may wear over time, requiring resurfacing.

Plaster application focuses on achieving a desired aesthetic finish on walls and ceilings, while screed application aims to create a level and solid floor base.

Both materials have variations with eco-friendly properties, such as reduced energy consumption in production and recyclable components.

Generally, plaster is used indoors due to its composition, while certain types of screed can be used outdoors, depending on durability and weather resistance.

Systems require screeds that can encapsulate the heating elements securely and conduct heat effectively without cracking.