Dry riser testing: what BS 9990 actually requires

What a dry riser is for

A dry riser is not a firefighting system in the way a sprinkler is. If you want the parts and how each one fails, that is what a dry riser is and how it works; this page is about what testing it requires. It is a pipe that lets the fire service get water up a building quickly, without running hose up the stairs. The brigade connects a pump to the inlet at ground level and takes water off a landing valve on the floor they need.

That means the whole thing sits unused, empty, for years at a time. It also means the day it is needed, nobody has time to discover that an inlet cap is missing, a landing valve is seized, or a cabinet has been painted shut.

The two intervals

BS 9990 sets two separate routines, and the common mistake is treating the annual test as though it replaces the six-monthly one.

Every six months: visual inspection. Inlets, landing valves, cabinets, caps, chains, signage and the access route. This is the check that catches the everyday damage: a missing cap, a blocked inlet, a cabinet key that no longer exists, a landing valve buried behind stored goods.

Every twelve months: full pressure test. The riser is charged with water to 12 bar and held for 15 minutes. That is the test that proves the pipework, the joints and the valves will actually hold pressure under working conditions.

Why the certificate matters as much as the visit

The visit proves the system works on the day. The certificate is the only part of it your fire risk assessor, your insurer or an enforcing officer will ever see.

Where firefighting equipment fails and maintenance cannot be evidenced, the responsible person carries that personally. A test that happened but was never documented is, from an enforcement point of view, very close to a test that did not happen.

What tends to fail

In practice the pipework itself is rarely the problem. What fails is everything around it:

• Inlet boxes that have been damaged, obstructed by parking, or had the cap stolen
• Landing valves that have not been operated in years and no longer turn cleanly
• Outlet caps and washers missing, which is what turns a 12 bar test into a wet floor
• Access, where a landing valve has quietly become the back wall of a storage cupboard

None of those need a specialist to spot. They need somebody to look, on a schedule, and write down what they saw.

What actually happens on the day

Worth knowing, because it tells you what to arrange and how long to give it.

The engineer isolates and checks the system is safe to work on, then connects a test pump to the breeching inlet and begins filling. Air has to come out as water goes in, which is what the automatic air valve at the top is for, and it is the first thing that shows up as faulty because a stuck air valve makes the fill take much longer than it should.

Once the riser is full it is brought up to 12 bar and held for 15 minutes. The engineer walks the riser during the hold, floor by floor, looking at every joint and every landing valve for weeping. A drop in the gauge is a fail; so is a visible leak even if the gauge holds.

Then each landing valve is opened and closed under pressure, which is the part a visual inspection cannot do. A valve that turns freely when the pipe is empty can still be unusable at working pressure.

Finally the system is drained down, the outlets are checked for debris, caps and washers are refitted, and the riser is left dry and back in service. On a tall riser the drain takes longer than the test.

What to arrange: access to every landing, somebody who can open locked cabinets, and a route for the drain water. In an occupied building the drain is usually the thing that decides whether the work happens in hours or out of them.

What a compliant certificate has to show

If your certificate does not carry these, you cannot evidence the test:

• The standard it was carried out to, named as BS 9990
• The date, and the address and identifier of the riser tested
• The test pressure and duration actually achieved, not “satisfactory”
• The number of landing valves tested and their locations
• Any defects found, with each one identified rather than summarised
• The engineer’s name and the company issuing it

The one most often missing is the pressure and duration. A certificate that says the riser “passed” without saying what it was tested at is not evidence of anything, and an inspecting officer who has seen a few of them will say so.

If it fails

A failed test is a normal maintenance event, not a crisis, and it should be reported that way: the fault identified, its location, and what putting it right involves. What must not happen is the system being left in an unknown state.

Where a riser cannot be brought back into service the same day, the building’s responsible person needs telling in writing, because the fire strategy assumed a working fire main and now does not. That is a decision about occupancy and about telling the fire and rescue service, and it belongs to the building rather than to the contractor.

A defect list with dates against it is stronger evidence than a clean sheet. A twenty-year-old riser that has never had a fault recorded is not a well-maintained riser, it is one nobody has looked at properly.

If you want the six-monthly and annual visits run properly against the standard, that is dry riser testing.

Where this sits in the wider routine

Dry risers are one of four recurring intervals a building with water-based fire protection owes. If your building has a charged main rather than an empty one, the regime is different and the comparison is in wet riser or dry riser.

Dry risers are one of four recurring intervals a building with water-based fire protection owes. The others are the weekly and quarterly sprinkler routines under BS EN 12845, and the annual full service that covers the pump as well as the system.