Drain air tests, water tests and CCTV: which evidence is needed?

A camera provides visual findings. DASA describes using footage to assess the inside of a drain and identify visible concerns. That is different from carrying out an air or water test with an agreed method and recording its result.

England's Approved Document H discusses water-tightness testing separately from inspection. Do not present a camera recording, an absence of visible defects or a note that water flows as if it were a completed water-tightness test. Equally, ask what a test result says about the particular section tested, rather than treating it as a report on the entire property.

Sources: DASA; Approved Document H.

Approved Document H's testing guidance refers to gravity drains and private sewers after laying, including relevant surrounding and backfilling work. It should not be turned into a claim that every existing home needs an air test before sale. Ask your designer and building-control contact what evidence is needed for the actual work.

Send the written requirement to the contractor before accepting a quote. Ask who will perform the work, whether anyone needs to witness it, which sections are included and what record the recipient will accept. If the request simply says 'drain test', resolve that ambiguity before the appointment.

For Scotland, Wales or Northern Ireland, obtain the relevant local requirements. The England document is not a UK-wide instruction, and this page is not a testing method or design specification.

Sources: Approved Document H.

Ask for the start and end points of each test section and how they relate to the drawing. Clarify whether the job includes inspection, testing or both. If preparation, access work or a repeat visit is needed, ask for it to be identified separately rather than leaving it hidden behind a package name.

A useful booking note records the purpose, recipient, drawing reference, included sections, requested method and expected deliverable. Add an explicit question about what happens if the proposed test cannot be completed. Do not choose equipment, pressure or acceptance limits from an online checklist; those decisions belong with the competent tester and the applicable requirements.

Sources: Approved Document H; HSE.

Before the visit, ask the recipient what the test record must contain. Our suggested review list is the property and drawing reference, date, section identifiers, method used, recorded result, limitations and the person or business responsible. These are organisational prompts, not an alternative technical standard.

Keep the camera report and testing record as separate documents if both are supplied. Check that they describe the same intended sections. If identifiers differ, ask the contractor to reconcile them while the work is still fresh rather than leaving a future buyer or building-control reviewer to guess.

• Can each result be traced to a labelled section?
• Is the method named rather than described only as a drain check?
• Are any omitted sections or inconclusive results explicit?
• Has the required recipient received the record?

Sources: Approved Document H; DASA.

Ask the tester to explain what the result establishes, what it does not establish and which investigation is proposed next. Request a separate reason and quotation for remedial work. A test result should not become an unexplained instruction to replace every drain at the property.

Leave drain access, isolation and test equipment to competent professionals. Never enter a chamber or attempt a pressurised test yourself. HSE warns that confined spaces can present serious hazards. A successful contractor test also does not, by itself, replace any separate consent or acceptance needed from the relevant authority.

Sources: Approved Document H; HSE.

• Who has requested the evidence, and for what decision?
• Do they require CCTV, an air or water test, or more than one service?
• Which drawing and pipe sections define the scope?
• Who confirms the applicable method and acceptance requirements?
• What written result must be provided, and to whom?
• What happens if testing cannot be completed?
• Are investigation, remedial work and any retest priced separately?

Find and check a drainage contractor when you are ready to ask for quotes.