Arne Glass, Specification Manager at Brymec, explores the issues surrounding ‘equal or approved’ products on projects, and what impact they can have on installer.
According to the Association of British Insurers, escape of water claims cost the UK construction sector roughly £2.5 million every day. That figure should stop any installer in their tracks. When a system fails after handover, the question becomes a very simple one: if it leaks, who pays?
The honest answer, more often than installers realise, is them. Much of that liability has nothing to do with the work installers actually carried out. It is inherited from procurement decisions taken long before anyone arrived on site.
The substitution problem
The “equal or approved” clause has become the single biggest source of compatibility risk on UK sites. It gives main contractors flexibility, helps with value engineering and keeps procurement moving. Across the industry, the vast majority of technical submissions still involve last-minute exchanges. Most are driven by price rather than performance; they look like sensible savings on the procurement spreadsheet. The problem starts when the components arrive on site and have to perform together as a system.
Too often, the result is a mixed-manufacture, sometimes mixed-material system, that nobody really owns. A fitting from one brand sits next to a valve from another, joined to tubing from a third. Each component might be compliant in isolation. Put them together and you have interfaces no one has tested and a warranty trail that quietly falls apart.
When the small print kicks in
Manufacturer warranties are not the safety net most installers assume. They are commercial documents with strict conditions, and those conditions exist so that claims can be challenged.
Take press-fit systems. To honour the warranty of up to 30 years on Brymec‘s Stainless Steel Press-fit System, we require the installer to hold a current certificate of training issued by us, to use approved press tools maintained and operated to the manufacturer’s requirements, to install on Brymec 316l stainless steel tube in a suitable environment for the correct application, and to retain all commissioning paperwork. Other manufacturers run comparable terms. They have to.
Now picture the substitution. The specified system gets swapped for an alternative on cost grounds, or for a product that brings lower quality, weaker technical support or accreditations. The installer trained on system A is asked to press system B, with a tool that may or may not meet the replacement manufacturer’s approved requirements. The job goes in. Twelve months later, a joint starts dripping above a server room.
The replacement manufacturer reviews the paperwork. They see no training certificate for their system and the tooling is unverified. Claim denied.
And here is the part the trade rarely talks about openly. Even where a warranty does pay out, it pays out on the product. As is the industry norm, manufacturer terms typically exclude liability for indirect or consequential loss. A £10 valve fails and the £50,000 of damage to the flat below sits with someone else. That someone is usually the installer, the main contractor or their insurer.
The liability rarely reflects who actually decided to substitute. The cost saving sat in one party’s budget, the approval moved through another’s submission process and the risk landed with the last party in the chain. It is the predictable outcome of a process in which no one is asked to think about the system at the point it is being designed.
Mixed materials, mixed messages
The mixed-material problem deepens once you look at the materials themselves. Plastic-to-metal connections are a good example. Plastics expand significantly more than metals under temperature change and that differential movement creates stress at joints, loosens seals over time and slowly works the connection apart. Failures here rarely come down to one bad component. They come from the joins, the thermal movement is seldom calculated across three different manufacturers’ kit and the gaps where one supplier’s responsibility ends and the next one’s has not started. None of these issues show up at commissioning. They surface two winters later, when the building is occupied and the cost of access and damage remediation has multiplied.
M&E consultants are feeling this pressure too. They are being asked to demonstrate genuine design assurance, not generic clauses. But by the time a job reaches the installer, the original specification has often been quietly rewritten through a chain of substitutions that nobody documented properly.
Push for one system, one warranty
There is a straightforward way to de-risk all this. It involves whole-system thinking at specification and extra vigilance at submission stage. Ask which party owns the interface between fitting and tube, or between different material types, such as Cast Iron drainage connecting to HDPE drainage. That connection can be perfectly compliant when it stays with a consistent manufacturer and the correct components are specified for the interface detail. The moment it crosses manufacturers, ownership of the join becomes a live question. Do the components share a tested compatibility envelope, or are they being assembled on hope? And if a substitution gets proposed later, who is qualified to confirm that it preserves the integrity of the assembly?
Single-source supply removes these ambiguities. Brymec’s hybrid model means we own the journey from factory to site, delivering connected systems through our own fleet and guaranteeing standing behind the whole package rather than a single product line. One point of contact, one technical team, one coordinated warranty position. When something needs investigating, there is nobody else in the room to point at.
That model also protects the installer’s training and tooling investment. Certificates stay valid against the system they were issued for. Approved tools match the fittings on the van. Commissioning paperwork lines up with what the manufacturer expects to see if a claim is made.
A practical ask
None of this requires installers to become experts in contract law. It calls for three habits that de-risk the point of submission. First, read the warranty conditions for every product on the schedule, not just the headline length. Second, flag any “equal or approved” swap that crosses a system boundary and ask the question on paper. Third, where single-source is not available, pinpoint the joint or interface at which the system warranty stops and get that risk allocated to a named party before sign-off.
The escape-of-water problem will not fix itself. But the installer who asks the candid questions at submission is the one least likely to be writing the cheque a year after handover.
