Drainage and septic tanks
A cracked septic baffle was seen by torch rather than by camera. Why is that look not a drainage survey?
A torch look is not a drainage survey because it only shows the baffle the light reached. The cracked septic baffle was seen from the chamber, not by a camera through the pipes. That records a crack in a part of the tank. It does not film the inlet, the outlet or the ground beyond. A septic tank is not a treatment plant, and it is not a cesspool, which only holds sewage until it is emptied. The survey has not jetted the system and has not sampled a discharge. The crack is a visual note. The drainage survey remains undone.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Baffles inside a septic tank separate the chamber so solids settle. A crack can mean the baffle no longer does that, or it can be a mark the torch exaggerated. Either way, the pipe run that feeds the tank and the route that leaves it were not travelled. A drainage survey is that travel, usually with a camera, written up as its own report. Borrowing the word because a light was shone into one tank overstates a limited look. The survey should keep the distinction, and so should you.
Ask a drainage firm for a camera survey if the pipes and the rest of the tank need to be known, and show them the torch note so they know a cracked baffle was seen. Tell the solicitor the home survey did not film the drains. Do not tell a lender a drainage survey has been done. Emptying and repairing a tank are later works. The crack is enough to justify the question. It is not enough to answer it.
What should you ask your surveyor?
- Was the baffle seen by torch rather than by a camera in the pipes?
- Does that look film the inlet and the outlet?
- Is a septic tank the same unit as a cesspool?
What are the typical next steps?
- Treat the torch note as not a drainage survey.
- Instruct a drainage firm if the runs must be filmed.
- Do not tell a lender the drains have been surveyed by camera.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a cracked baffle mean the tank must be replaced?
Not on the strength of this look. The survey saw a crack by torch. It has not specified a repair and has not emptied the tank. A drainage firm may say the baffle can be repaired, or that the tank is finished. That is their conclusion, after a proper look. The home survey has not reached it.
Was the discharge from the tank sampled?
No. Nothing in a torch look samples the liquid leaving the tank. Quality, consent and the state of any outfall stay outside this note. A septic tank and a treatment plant are tested differently, and neither test happened. Ask the solicitor for any permit or emptying record. The crack is not a sample result.