Floors - Topic Home

 

Introduction

By the end of the 19th century most new houses in towns and cities were built with timber ground floors. Imported softwood (deal) accounted for most of the timber; only a very small percentage was home-grown. The floors were constructed from a series of timber joists supporting square edged floorboards. The design and construction of timber floors has changed over the last 100 years although these changes have been in the detail,  not the principle. Modern timber floors are still constructed from softwood joists but nowadays there are stricter rules (in the form of Building Regulations) to prevent risks of damp and rot. In fact, timber floors are fairly rare in modern construction because most ground floors are made from concrete.
Concrete floors were not uncommon in the late Victorian period although they were often confined to certain rooms. Large suburban houses, for example, might have kitchen and hall floors formed in concrete, possibly with a tiled finish. Not until the 1950s was it common to find the entire floor cast in concrete. These floors were often finished with wood blocks or a sand/cement screed covered with asbestos tiles - the fitted carpets we take for granted today were rare until the 1960s. A concrete floor is basically an insitu slab of concrete poured over a levelled and compacted base. The floor is supported by the ground beneath it, not by the house walls. Nowadays a damp proof membrane (DPM) should be included somewhere in the construction to prevent capillary action (rising damp).  
There are a variety of conditions which are not suitable for insitu ground floors. These include wet sites (ie, high water tables), ground containing aggressive chemicals, sloping sites, and sites with poor ground. In these situations it is often more practical and economic to use raised, or suspended concrete floors. These do not 'sit' on the ground but are supported by the house walls. Nowadays most suspended floors are made from pre-cast inverted 'T' beams with a block infill.
Upper floors have been formed from timber for centuries. An upper floor structure in a Georgian town house would look pretty much the same as a floor in a modern suburban estate. Again the differences are in the detail, for example the nature of support and fixings. Floor boards have largely been replaced by chipboard and strand board, traditional carpentry joints by galvanised straps etc. However, in new blocks of flats timber upper floors are rare. They cannot provide the requisite levels of sound insulation and fire protection. In flats, therefore, concrete floors are the norm.
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