This type of construction system consists of an internal and external sleeve of Styrofoam or Neopor linked together by ties to form a building block.
Special trestles assist to give the walls a precise lining and provide a working platform off which to pour the concrete.
A superior quality system known as styrostones, ICF or PIF will provide a wall shutter capable of safely accepting a concrete pour of up to 3m high in one continuous pour. This determines that most projects can be built one storey at a time = less pump visits . Where time is critical, the project can be fast tracked to a weather tight stage in a minimum period. This enables all the follow on trades to mobilise earlier thus saving money in all areas.
The density of the Styrofoam/Neopor should be at least 25g/l or 25kg/m³ to be robust enough to withstand the pressure of a concrete pour and sufficient compaction.
Boards formed from Neopor have a superior thermal insulation value than that of a Styrofoam board of equal dimensions. Styrofoam however is inexpensive and might be sufficient for certain climate conditions.
The core for the concrete is usually 150mm and suitable for 95% of all European buildings. Dwellings of up to 6 storeys high and earthquake proof up to Richter scale 7 can be constructed using a 150mm core. For other cases a 200mm core for concrete can be provided.
There are 4 basic concepts for the ties:
ties of styrofoam/Neopor (monolithic styrostone)
pre-fixed plastic ties
pre-fixed metal ties
separate delivery of ties to be assembled on the construction site