Is a Drain Survey Possible Without a Manhole?
Manholes are an integral part of a drainage system that give clear access points to the underground piping, allowing CCTV surveys to be carried out above ground so that the condition of the pipes can be inspected without the need for intrusive excavation work, but what happens if you don’t have a manhole?
We’ve put together this helpful guide to give you all the information you need.
Firstly, are you sure you don’t have a manhole?
Prior to 1966, when Building Regulations were put into force nationwide, it was not uncommon in the Victorian era for manholes and drainage access to be obscurely placed, with each borough or builder having a different preference for placement, while in the 1960s, a confusing shared system for housing estates saw many separate storm and foul systems for the estate placed surrounding a corner property – although in some cases not actually serving that property itself – so it is very likely that you do have an access point, it’s just hard to find!
It is also a possibility that, in the name of aesthetics, your manhole has been covered up or buried, especially if the manhole was somewhere in the property’s garden.
It is very unlikely that there is no manhole or access point to your drain, it’s just a matter of finding it.
How to find buried or hidden manholes
However, it’s all well and good to say that you must have an access point, the tricky part comes in locating it! Try these methods to find your manhole cover before you give it up as a lost cause:
- Ask your local water provider – Contacting your local water board may help, as it is possible that they will be in possession of maps of the drainage system in the local area, helping you to gain some insight into some possible locations for your access point.
- Check your neighbour’s property – If your neighbour’s property is the same construction as yours, it is possible that the two buildings were built in mirror of each other and that your chamber will be in the same location as theirs. If this is the case, your neighbour’s, and therefore your, chamber will likely be on the front boundary line of the property, although yours may be hidden or buried.
- Use a metal detector – If your manhole is buried, it is normally quite shallow (just inches below the surface), so you could buy or loan a metal detector to locate your manhole. This is an effective way of checking your garden or tarmac for signs of entry. However, if your manhole cover is stone and not metal, this will not be much help at all.
- Try a road pin – To check soft ground, such as your property’s garden, for a manhole, you could try a road pin. This is simply a long metal point that you can use to poke deep into the ground and see if you meet any resistance. This will work for both metal and stone manholes, but unless you have an idea where the manhole cover could be, this could be a long task.
If you really can’t find your manhole
If none of our tips have helped you locate your manhole cover, a professional drainage team may be able to locate it for you. Failing that, a drain survey is indeed possible without a manhole.
A hole can be bored through a section of pipe and a survey conducted this way. Although this is a more intrusive method of performing a survey, and will require some excavation work, the CCTV survey will allow the full drain layout to be mapped, and can help locate that missing manhole for easier access next time. And don’t worry about the hole in your pipe, either – that can be patched up or relined to ensure that your sewers continue to function as they should after the survey has been carried out.
Express Drainage Surveys offer residential drain inspections and commercial CCTV surveys at affordable prices. Our expert engineers offer flexible time slots to visit your property around your schedule with our 24 hour services, and a full report and accompanying DVD will be provided so you can evaluate the condition of your drain yourself.
To make things even easier for you, when a survey conducted by us shows a defect, we can deal with your insurance provider on your behalf, taking care of all aspects of your problem for you. Contact us today to find out more – we’ll be happy to help with any query you may have.