A Christchurch property owner contacted ACS Air Control Systems because a tenant had a new heat pump installed and it started leaking through the roof. This case study shows the problem, what we did to repair it properly, and the result. If you have concerns about heat pumps, Christchurch heat pumps, heat pump repair, or heat pump installation for a commercial building, contact ACS via our contact form.
The Problem
We received a call from a property owner advising that one of their tenants had arranged a heat pump installation for a café tenancy. Soon after the install, water began leaking through the roof.
On inspection, we found a poorly executed installation that had compromised the roof waterproofing. This type of workmanship is often the result of installers who undercut on price, then cut corners on materials and detailing. It becomes a false economy because the cost of rectifying a poor heat pump installation frequently exceeds the cost of doing it correctly in the first place.
The main cause of the leak was that the pipework was not properly sleeved. When pipes are not sleeved through the roof penetration, water can track down the outside of the pipework and enter the roof cavity.
We also found several other issues with the original installation:
- The original installer placed decktite straight onto the butynol with no proper sleeving for the pipes to pass through.
- They cut flexible ducting in half and wrapped it around the piping as a substitute for correct penetration detailing.
- They fixed timber straight to the butynol using nails, without appropriate sealing methods, creating multiple potential leak points.
- The outdoor unit was sitting on that timber, increasing the likelihood of movement and ongoing water ingress risk.
In a commercial café environment, this kind of failure can quickly lead to damaged ceilings, insulation, and internal finishes, along with disruption to trading.
What Was Done
ACS carried out remedial work focused on restoring roof integrity and ensuring the heat pump installation was properly weatherproofed.
Our repair process included:
- Removed the outdoor unit and accessed the affected area
We removed the unit to allow full access to the roof penetration and surrounding membrane so the defects could be repaired properly, not patched around. - Removed part of the old butynol
We removed the damaged and poorly detailed section of butynol that had been compromised by the original workmanship. - Replaced waterproofing and rebuilt the mounting area correctly
We replaced the old butynol with new. Treated timber was installed, then butynol was applied over it. This provides a more robust base and helps preserve protection of the roof. If any water were ever to get past the top layer, the underlying butynol still provides protection for the roof structure. - Sleeved and secured the pipework correctly
We sleeved the piping with unpunched nova flow and secured everything properly. Correct sleeving prevents water from tracking down the pipes into the roof cavity and is a core requirement in a watertight heat pump installation. - Reinstalled the unit and confirmed operation
After the roof and penetrations were corrected, we reinstated the outdoor unit and ensured the system was operating as required for the café tenancy.
The Result
The leak was stopped, the roof penetration was made watertight, and the heat pump operationally now met the commercial café’s needs. The property owner also gained assurance that the installation had been rectified in a way that protects the building, rather than relying on temporary or cosmetic fixes.
If you are dealing with a leaking roof penetration, questionable workmanship, or you want a professional assessment before problems occur, contact ACS via our contact form for expert heat pump repair and heat pump installation in Christchurch.
Job was on a Commercial building - (café)
We received a call from a property owner, that one of tenants got a heat pump installed and now it’s leaking through the roof. We found a rather interesting installation, which is to be expected from cowboys, that’s ruining the industry, by undercutting the price, but then delivers this kind of workmanship.
The pipes were not sleeved which causes water will run down the pipes and into the roof.
Taking the cheapest quote means something gives – and that is often workmanship – and becomes a false economy as rectifying poor installation often costs considerably more than ding it correctly in the first place
Initial installation.
The original installer decktite straight onto the butynol, without any proper sleeving for the pipes to go through. They just cut some flexible ducting in half and wrapped it around the piping. Fixed the timber straight to the butynol too, with nails, without proper sealant and had the unit sitting on that.
Our repairs
Removed the unit and part of the old butynol. Replaced the old butynol with new, had treated timber installed and then butynol over it. This way, should there be any water leaking through, it still has the original butynol to protect the roof. Sleeved the piping with unpunched nova flow and secured everything properly.
Outcome – the leaking was stopped and the unit running as needed.
