The different types of concrete that house and flats can be built with .
The Main Types
Up to the 1950’s, Flats were built out of a number of no traditional construction materials as per the ones below.
Orlits
These are properties that are built with a concrete frame and concrete floors , the floors were usually finished with Timber , the walls were concrete blocks tied together with steel ties , the first Orlits were built with a flat roof but were then later built with traditional pitched roofs for better water drainage .
Wilson Blocks
They are pre-made concrete blocks, they are often given a finished face or can be rendered once in place , the big problem with them is the steel ties are prone to rusting .
No Fines
This was a very popular concrete for flats that were built in the 50’s through to the 70’s, the building was constructed by a poured concrete that contained a no fine aggregate concrete. This construction proved a better insulation than than most other concrete, giving the same insulation as a cavity brick wall without the insulation inside the cavity. The reinforcement was usually above windows or doors or at the level near the eaves. This was for openings wider than 1500mm or 5 feet and the concrete would have precast lintels built into the structure near the opening or at the eave level as needed. The main issue was if the position of a window or door needed to be moved the lintel as they were cast into the structure were too hard to move.
Crosswall construction
These were used in the 1950’s for a lot of four storey tenements flats. These had concrete walls running front to back and the second floor was also made from concrete, the front and back walls were generally made of brick. There was an issue with Damp proof courses above openings and the concrete floors especially in higher floors.
Glasgow foam slag
This is a construction that is made from pre-casted concrete panels made using a foamed slag, these were usually formed of site and carried to the construction on suitable lorries . As per No Fines concrete the building would be then rendered externally .When this type of concrete was used in four storey tenements, the second floor was usually concrete with the first and top floors in timber.
Boot Pier and Panel system
These were usually semi detached but four-in-a-block flats were also built in the interwar years in Dundee and Glasgow.
Atholl Steel
This was used in some four-in-a-block flats built after 1945. These had a steel frame and bitumen-painted steel sheet external walls. Condensation could occur within the wall and then rust the external steel panels.