Screed - wikipedia Screed This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( February 2011 ) Screed has three meanings in building construction : 1 ) a flat board ( screed board, floating screed ) or a purpose - made aluminium tool used to smooth and true materials like concrete, stucco and plaster after it has been placed on a surface or to assist in flattening ; 2 ) 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 ) ; 3 ) 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 ( traditionally sand and cement ), poured in site on top of the structural concrete or insulation, on top of which other finishing materials can be applied, or it can be left bare to achieve a raw effect. Contents 1 Screed boards 2 Screed rails 3 Liquid and flow screeds 4 Screed coats 5 See also 6 References 7 Sources Screed boards US Navy Seabees use a screed ( board ) to screed ( verb ) wet concrete. The form - work acts as screed rails. The screed on this paver spreads and smooths the asphalt. In the US, screeding is the process a person called a concrete finisher performs by cutting off excess wet concrete to bring the top surface of a slab to the proper grade and smoothness. A power concrete screed has a gasoline motor attached which helps smooth and vibrate concrete as it is flattened. After the concrete is flattened it is smoothed with a concrete float or power trowel. A concrete floor is sometimes called a solid ground floor. A plasterer also may use a screed to level a wall or ceiling surface in plasterwork. This sense of screed has been extended to asphalt paving where a free floating screed is part of a machine which spreads the pavement. Screed rails The wood pieces labeled `` beveled nailing strips '' act as screed rails in this installation of a screed coating on Hy - Rib brand wire lath A weep screed or sill screed is a screed rail which has drainage holes to allow moisture which penetrated an exterior plaster or stucco coating to drain through the screed. Liquid and flow screeds Flowing screeds are made from inert fillers such as sand, with a binder system based on calcium sulphate. Consequently they can look very similar to a sand / cement screed Flow screeds are often preferred to traditional cement based screeds as they are faster to install and provide a similar finish. Flow screed is most often used in combination with underfloor heating installation as the reduced thickness provides for more effective and efficient heat transfer. One of the main advantages of liquid flow screed is that, it offers few additional benefits compared to sand and cement. It is anything but difficult to pour, with fluid properties that consider an expedient application and quicker drying time. There are n't any bigger advantages of this product than when combined with underfloor heatingsystem, a lesser thickness of liquid flooring screed, when compared with conventional screeds, minimises heat storage leading to a floor that reacts quickly to user requirement hence raising the efficacy of your underfloor heating method. Screed coats All - in - one screed ( material ) pumping truck A development in the UK is the delivery, mixing, and pumping of screed from a single vehicle. Where previously screed jobs required a separate pump to administer the screed, these new machines can now administer the screed directly from the mixing pan to the floor at a range of up to 60 meters. For example, the material called granolithic. See also Screed wire, an alternate name for a ground wire in electrical work Screedboard, a proprietary gypsum board References Jump up ^ `` Construction Dictionary ''. Website Upgrades Inc. 2000. Retrieved 2007 - 05 - 21. Jump up ^ `` screed, n. 3 '' and screed, v. 4. '' Oxford English Dictionary 2nd. ed. 2009. CD - rom. Jump up ^ wisegeek.com accessed March 22, 2015 Jump up ^ `` Tiling onto anhydrite screeds. ''. Net Weber. Retrieved 20 April 2017. Jump up ^ Hillier, Neil. `` Flow Screed ''. Flow Screeding Services. Retrieved 20 April 2017. Sources Constructing Architecture -- Materials, Processes, Structures : A Handbook ; Andrea Deplazes ( ed. ) ; Birkhauser, 2005 Look up screed in Wiktionary, the free dictionary. Concrete History Roman concrete Roman engineering Ancient Roman architecture Composition Cement Portland cement Water Water -- cement ratio Aggregate Reinforcement Fly ash Ground granulated blast furnace slag Silica fume Metakaolin Production Plant Concrete mixer Volumetric mixer Reversing drum mixer Slump test Flow table test Curing Concrete cover Cover meter Rebar Science Properties Degradation Environmental impact Recycling Segregation in concrete Types Energetically modified cement Fiber reinforcement Rosendale cement ( natural cement ) Perviousity Precasting Pre-stressing Ready - mix Reinforcement Roller - compacting Self - consolidating Mass Polymer Filigree Voided biaxial slab Lunarcrete Reinforced column Foam Construction Formwork Climbing formwork Slip forming Screed Power screed Finisher Power trowel Pump Float Sealer Organizations American Concrete Institute Institution of Structural Engineers Indian Concrete Institute Nanocem Portland Cement Association Book : Concrete Category : Concrete Retrieved from `` https://en.wikipedia.org/w/index.php?title=Screed&oldid=801917242 '' Categories : Concrete Floors Pavements Construction Hidden categories : Articles needing additional references from February 2011 All articles needing additional references Talk Contents About Wikipedia Deutsch Esperanto Français Nederlands Polski Русский Edit links This page was last edited on 22 September 2017, at 19 : 18. 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Question: what is the top layer of concrete called
Answer: Screed