Pre-Purchase Drain Survey: A Buyer's Checklist

Which properties are worth surveying

Anything with original clay drainage, which broadly means pre nineteen seventies. Anything with mature trees within about ten metres of the run, because roots find any defect that exists. Anything that has been extended, since new connections into old pipework are a frequent source of trouble. Anything with a driveway or hard standing over the drainage, because that is where excavation is expensive.

Also worth it for rural properties on a septic tank or treatment plant, where the drainage is not simply a pipe to the street and where a failed system is both costly and a regulatory matter.

Timing it around Scottish missives

The window is between having your offer accepted and concluding missives. Once missives are concluded you have bought the drainage as it stands. Because that window can be short, tell the surveying firm the deadline when you book, and confirm they will turn the report around inside it.

We prioritise pre purchase work for exactly this reason and will normally attend within a couple of days and report within one to two working days after that.

What to ask for when you book

• Full CCTV inspection of the main foul run and, where present, the surface water run.
• Video footage supplied to you, not just a summary sheet.
• Still images with distances and depths for every defect.
• Costed repair options for anything found.
• A plain English summary your solicitor can read without a drainage background.
• Confirmation of where private drainage ends and the public sewer begins.

Getting access on someone else's property

You will need the seller's permission, arranged through the selling agent, and it is very rarely refused. Occupants are usually asked to avoid using water for the hour or so the inspection takes, which is worth mentioning in advance so the visit is not cut short.

If access is refused outright, that in itself is information. It is unusual, and it would make us want to look harder at the drainage before committing.

Using the findings

Most surveys find something and very few find something that should stop a purchase. What the report gives you is a number. A costed repair schedule allows your solicitor to seek a price reduction, a retention until the work is done, or a commitment from the seller to carry it out before entry.

Even where the findings are minor, you gain a dated record of the condition of the drainage on the day you bought, which is genuinely useful if a dispute or an insurance claim arises later.

What a survey cannot tell you

It cannot predict when a marginal defect will fail, and it will not cover pipework it cannot physically reach, such as a run with no accessible chamber and no rodding eye. Where the camera cannot travel the full length, the report should say so plainly and explain why, since a heavy root mass or a collapse is often the reason it stopped.

It also covers drainage, not plumbing inside the property. A leaking waste under a bath is a different inspection.

What it costs relative to what it protects

A pre purchase CCTV survey on a standard house is a fixed price and a small fraction of a single excavation repair, which is the comparison worth making. It is also considerably less than the price reduction buyers routinely negotiate when a genuine defect is found and documented.

We quote before attending, attend quickly because purchase deadlines do not move, and provide the footage, the still images, the depths and a costed schedule. If the drainage turns out to be sound, you have paid a modest amount for a dated record and the ability to stop worrying about it.

It is also worth asking the selling agent whether the seller holds any previous survey or repair paperwork. A dated report from three years ago and a fresh inspection together tell you whether a defect is stable or getting worse, which is a far more useful picture than either on its own.

If the property is on a septic tank or a treatment plant, ask for the tank and the drainage field to be included. Those are the findings that cost the most to put right and the ones a standard house purchase check will never surface.

Questions we get asked