Adding a tank, air-conditioning unit or other roof equipment changes more than the equipment layout. The owner needs an agreed plan for support, services, access and the existing waterproofing. Arrange that coordination before anyone delivers a base or starts drilling. A small intervention can involve several contractors with different responsibilities, so the useful starting point is a marked roof plan showing the proposed work and the people who must approve its interfaces.
Have the proposed location reviewed
Give the responsible engineer the proposed equipment information and intended location, including any future expansion already planned. Ask for confirmation of the required structural assessment and supporting details. Do not treat an unused corner or an existing plinth as evidence that a new tank or unit can be placed there. Keep the equipment supplier's information with the engineer's response. The owner coordinates the decision; load assessment, anchoring design and alterations to the structure belong to qualified professionals working with the actual building information.
Identify the roof system before designing the interface
Locate the waterproofing handover file and identify the installed products, layer arrangement and warranty contact. If records are missing, arrange a professional assessment rather than guessing from colour or appearance. Manufacturer roofing information distinguishes different systems; it does not make their detailing interchangeable. Ask the waterproofing specialist to review the proposed support and service interfaces. A detail that works for another roof should not be copied without confirming its suitability for the system and conditions present at this property.
Coordinate every penetration and support
Ask for a drawing or marked photograph identifying proposed bases, fixings, pipes and cable routes. The relevant professionals should explain which parts interact with the waterproofing and how those interfaces will be completed. Assign responsibility for the supporting work, installation and final waterproofing treatment. Avoid letting each trade finish its own small portion without a shared detail. If the equipment arrangement changes on delivery, return the changed interface for review before work proceeds; an approved position does not automatically approve a different one.
Plan the delivery and maintenance route
Agree how equipment and materials will reach the working area and how the roof will be protected during handling. Ask who checks the route before work and after removal of temporary protection. Include space for the future technician to reach service points without improvising access across the roof. Discuss drainage access and the ability to inspect nearby waterproofing. A hypothetical tank placement may fit its footprint while obstructing a service route, so review everyday maintenance as well as the initial installation drawing.
Keep the equipment programme tied to the roof programme
Schedule waterproofing attendance at the stages when its interfaces can still be inspected and completed. Clarify whether the roof installer must return after mechanical or plumbing work, and include that visit in the price. Record who authorizes concealment or loading of a completed detail according to the project requirements. The owner should not have to mediate a finished roof installation followed by an unplanned equipment visit. A coordinated sequence makes the responsibility for temporary protection and unfinished interfaces visible throughout the work.
Close the work with a focused inspection
Request a documented inspection of the affected route and installation area, not just a photograph of the operating equipment. Keep any professionally specified checks and closure records for disturbed details. Update the roof plan, maintenance instructions and warranty correspondence. Confirm the service contact for both the equipment and waterproofing. If a later leak is reported, the updated file should show what changed, when and where, allowing the investigation to begin with evidence rather than assumptions about which contractor caused it.
Your practical checklist
- Review location and support with the responsible engineer.
- Identify the existing waterproofing system and warranty terms.
- Approve interfaces, handling routes and attendance sequence.
- Inspect affected areas and update roof records.
Frequently asked questions
Can I put a new tank on an old concrete base?
Have the engineer assess the proposed tank, base and building information. The presence of an existing base does not establish that it is suitable for the new installation.
Can the equipment installer simply seal around its fixings?
Ask the waterproofing specialist to review the actual interface and assign the work clearly. A generic sealing promise does not demonstrate compatibility with the existing roof assembly.
Should the roof installer attend after equipment work?
Agree attendance with the responsible professionals before starting. The required stages depend on the interfaces; any return visit and post-work checks should be included in the coordinated scope.
Sources and further reading
Sources support the specific facts identified below. Planning examples and checklists are editorial guidance; photographs are illustrative.
- Sika GCC: roofing systems — Reference for professional review.