Victorian properties are generally built with timber sub floors to ground and upper levels with the exception of the rear addition which is sometimes built with concrete oversight.
Timber sub floors often suffer from a camber, creak or are slanted. This can be a cause for concern for occupiers and purchases as they often relate this to more serious movement issues.
While movement to sub floors can be a symptom of wider subsidence or foundation movement, commonly it is due to issues localised to the floor itself.
Ground floors were often built on sleeper walls which are brick built walls at basement level which bear the load of the floor joists. Quite often these walls were built in a crude way and often they are only remaining vertical under their own weight.
Therefore, any assessment of movement within the ground floor structures should start with an assessment of the sleeper walls. Often assessment within the basement will reveal sleeper walls which are not structurally sound, joists which are not bearing on sleeper walls or rotting joists which may be built into external or party walls. Insect attack can also be evident. However, insect attack, only in the rarest of cases, would lead to structural instability.
By modern standards, the Victorians built with thinner profile joists than would be recommended today and built into external walls which can lead to rot of joist ends where the wall itself is wet. This is opposed to modern methods of construction which would generally hang joists off specialist hangers so that they are not in direct contact with wet masonry.
Floor structures built by the Victorians were not intended to take the dead loads imposed by modern living and this can lead to stresses on floor joists and consequent overloading issues.
Furthermore, the need to notch joists in order to run say central heating pipework or electrical wires can also weaken the joists.
In summary, visible movement to timber floors can of course be a symptom of serious structural issues, however in most cases it is often little more than a nuisance than symptomatic of anything materially structural.
Our building surveyors a are adept at inspecting and identifying issues during building surveys, schedule of works or defect reports.