WPS floor slabs (Wroclaw floor slab). Large-surface unsupported ceiling
The WPS ceiling from BUDMATER Sp. z o.o. is distinguished in the market by its light assembly technique, which does not use formwork and punches. The advantage of this technology is that there is no need for supports, so the WPS ceiling does not burden the ceilings of the lower floors. This feature predisposes the use of ceilings, for example, during the renovation of townhouses. Another indisputable advantage is the large span of the WPS ceiling, limited only by the length of the I-beam steel beam used.
What is a WPS floor slab?
TheWrocław Floor Plate ( WPS for short) is a prefabricated reinforced concrete structural element designed for the construction of floors in renovated and modernized buildings as a load-bearing element laid between steel floor beams. The WPS slab floor is a technology consisting of load-bearing ribs - steel I-beams, which are filled with prefabricated reinforced concrete slabs, just called WPS slabs.
History of the WPS ceiling
The WPS ceiling was designed based on the guidelines of the Municipal Design Office in Wroclaw, 2 Olawska St., in May 1980.From the place where this type of ceiling was designed we owe its name - WPS, or Wroclaw Floor Slab. The author of the idea was Jerzy Gajczewski, M.Sc. and the author of the design was Zygmunt Domaszewski, M.Sc.
Prefabricated WPS 100 slab
© BUDMATER
Wrocław floor slab - advantages
The use of WPS slabs(budmater.pl/plyty-wps) completely eliminates formwork and scaffolding necessary for monolithic ceilings. In addition, the use of WPS slabs greatly reduces the duration of the work and does not require highly skilled workers. Steel beams can be introduced into all rooms without the use of a crane. In addition, the beams can be divided into shorter sections in exceptional situations and assembled on site. The shape and dimensions of the slabs have been adapted for manual transport and installation by two workers.
The main features of the WPS ceiling
- elimination of formwork
- no need for a crane
- no assembly supports
- no need to employ highly skilled workers for installation
- large spans up to 12 m
- elimination of burdening the ceilings of lower floors
- all lengths of WPS boards are available in large quantities (manufacturer BUDMATER.pl)
- possibility to transport panels over long distances
- possibility of ceiling assembly on construction sites with logistic difficulties
- the ease and speed of making the ceiling project.
Prefabricated reinforced concrete slabs of WPS ceiling
© BUDMATER
WPS ceiling - construction and principle of operation
Steel beams are set in sockets in the wall. For the support of the steel beams, concrete pads are made in the sockets. After the beams are installed, the sockets should be concreted.
WPS slabs are designed for uniformly distributed loads. Do not load the slabs with heavy partition walls and other concentrated loads. For partition walls located parallel to the position of the floor beams, additional steel beams should be made, and for walls located perpendicular to the position of the beams, reinforced concrete ribs should be made on the WPS slabs. At the level of the upper flange of the steel beams, a layer of concrete ~5 cm should be made to protect the steel beams from sagging. In addition, the steel beams should be concreted. Steel beams are not recommended to be protected with corrosion protection for better adhesion of concrete. The lower flanges of the beams should be meshed and plastered with the rest of the ceiling surface.
In places where the modular WPS slab does not fit between the beams, reinforced concrete screeds should be made. The spouts, due to their short span of up to 0.9 m, can be reinforced with ø8 bars every 10 cm at the bottom with the reinforcement on the supports turned upward.
Technical data of WPS boards
- width: 400 mm
- length: 800-1500 mm in 100 mm module increments
- height: 80 mm
- reinforced elements: 40 cm
- concrete class B-25
- weight of the element is about 100 kg/m².
Sketch of concreted floor beam
© BUDMATER
Supporting structure of WPS ceiling - beams made of steel profiles
For the construction of WPS slab ceilings, regardless of the requirements of load-bearing capacity and use limit states, use beams with such a foot width as to ensure the support of the slabs for at least 3 cm. Hot-rolled steel profiles made of ST3S structural steel are used for the floor support structure. Steel beams should be cleaned before building in.
Fire protection boards - protection of WPS alloy steel support beams.
To ensure adequate fire resistance of the ceiling, we must take care first of all to protect the steel beams. To protect the beams, we can use:
- fire protection boards, e.g. Promatect from Promat or equivalent, according to the system selected by the Contractor for obtaining fire resistance class of the ceiling REI 60 or REI120
- protection of steel ceiling joists by spraying or painting with a set of intumescent fire protection paints after approval of the presented solution by the Engineer
- fire-resistantgypsum boards GKF 1.25 cm thick.
Diagram of the arrangement of beams in the corridor between the elevator shaft walls
© BUDMATER
WPS ceiling installation in practice
The assembly of the WPS ceiling can be carried out only on the basis of the structure assembly project provided by the work contractor. Assembly workers must be trained, familiarized with the organization of the assembly and the equipment used. The passage of people on the level directly below the assembled ceiling is not allowed. The weight of WPS boards varies between 40 and 70 kg, so the installation of a WPS board ceiling can be manual - without the use of any heavy equipment. For WPS ceiling installation, AI-AII class steel beams are used with such a foot width as to provide adequate support for the slabs (at least 3 cm).
Laying WPS slabs
It is very important to lay the floor slabs tightly next to each other, as the joints are filled with concrete. In turn, the place where the slab and beam meet is filled with a thin cement mortar.
WPS ceiling insulation
Various materials are used to insulate the WPS ceiling (recommended by BUDMATER are, for example, expanded clay, polystyrene, mineral wool, polyurethane), which are laid directly on the slabs, then a final layer of concrete is laid over the whole.
Finishing the WPS ceiling
Finishing the ceiling from below is at the discretion of the investor, however, the most common practice is to plaster the ceiling with at least a two-centimeter layer of cement-lime mortar.
For more information, visit the BUDMATER Sp. z o.o. company's page on the A&B portal.
