Do I need a drain test or a drain survey before I buy a house?

We are contacted by many prospective house purchasers every week. They have normally just received a homebuyers report from their surveyor.

The report will advise that the purchaser get the property’s drains inspected to check for any defects, that may lead to subsidence.

The report will inevitably suggest they find a suitable drainage company to arrange to have a drain survey and a drain test carried out at the property.

But which one do you need or do you need a drain test and a drain survey?

Do you need a drain survey of a drain test before you buy a house?
Do you need a drain survey of a drain test before you buy a house?

What will a pre-purchase drain survey give you?

A pre-purchase cctv drain survey will check the condition of all the underground drainage system at the property you are hoping to buy.

A comprehensive drain survey report will provide information regarding the layout, pipe size, material, flow direction and any defects found.

You will receive screenshots and footage of any defects seen by the cctv camera, with a quotes for any remedial works that are required.

What is a drain test?

In layman’s terms, a drain test is carried out by isolating each drain run with bungs. Air (or in some cases water) is then pumped into the line.

The engineer will the monitor the drop in pressure over a 5 minute period. A large drop in pressure over this time will indicate defects in the line.

This would indicate a failure. The only information that a drain test will give is a “pass” or a “fail”. There is no other information available from your drain test.

Why do people have drain tests?

The only reason that people ever have a drain test done for a property is that Building Control tell them they have to have a test done on new drainage.

What happens if a drain test fails?

The next step would be use a cctv camera to check the line for any defects in the line. Once any defects are found and repaired, the test can be redone.

Do I need a drain test done before I buy a house?

The simple answer is NO. If you are purchasing a property, you need to know that there are no leaks in the underground drainage that could be affecting the structural integrity of the house by causing subsidence.

If there are any you defects, you need to know how much it will cost to carry out the repairs. For this you will need a cctv drain survey NOT a drain test.