There are no shortage of contractors with drain camera inspection units but this kind of specialist investigation differs from your standard drain camera survey, i would estimate that 60% of the sites we visit have been surveyed at least once before and the home owner has usually been told that there are no defects sufficient enough for rats to leave the system only for us to discover an obvious defect within an hour of arriving on site
Unfortunately most of these defective surveys comprise of pushing a camera up and downstream of a manhole or chamber when in fact you need to survey every inch of the drainage system including branches
Whenever anybody mentions that they have seen a rat it is usually followed by "as big as a" Cat, Dog, Pot Bellied Pig etc when in reality there is not a lot to a rat in the way of large bones apart from of course the sabre toothed variety, they can therefore squeeze through the smallest of gaps and you are basically looking for a hole the size of a 50 pence piece. It is therefore vital that every branch line and connection is surveyed up to gully pots and rest bends adjacent to you house foundations not to mention any drainage that actually runs beneath your property.
Even if your property has several inspection chambers (and many have no access points at all) it is unlikely that all drainage connections are accessible so it often takes some effort and skill to complete a detailed and worth while survey.
Next page - typical points of access for rats |