How to Protect Underfloor Heating Pipes During a Concrete Pour

✔ Step-by-Step: How to Protect Underfloor Heating Pipes During the Concrete Pour

1. 1

   Fully Pressure-Test All Pipe Loops Before Pouring

   Always fill and pressurise the underfloor heating system prior to any concrete work. This makes the pipes more rigid, helps spot leaks before it’s too late, and makes any accidental damage immediately noticeable. Most systems are tested to 3–5 bar and left under pressure for at least 24 hours before and during the pour. Never pour over unpressurised pipes — the risk of hidden leaks or flat spots increases significantly.

2. 2

   Check All Fixings and Re-Secure Loose Pipework

   Before the pour begins, walk the site and inspect every loop. Look for loose ties, floating sections, or tensioned bends that could spring up. Re-secure any movement-prone areas using additional clips or ties. Pay particular attention to pipe returns, manifolds, and areas near expansion joints. Reinforcement mesh systems may shift as well — make sure any supporting bars or chairs are still in place and stable.

3. 3

   Use Barriers and Access Planks to Avoid Foot Traffic on Pipes

   Foot traffic from the concrete crew can damage exposed pipes. Before the pour starts, lay protective planks or wide scaffold boards across the floor to create walking routes. These should span multiple pipe loops and rest on firm support — not directly on pipes. Mark sensitive areas such as manifolds, bends, or clip junctions to avoid accidental damage. Don’t allow wheeled barrows or machinery to roll over the pipe zone unless a protection layer is specified.

4. 4

   Pour in Layers and Use Controlled Placement Methods

   Begin pouring with an initial layer of concrete (around 30–50 mm) to anchor the pipework. Use a pump or chute to place the mix gently over the surface rather than dumping large volumes directly onto exposed pipes. Once this bedding layer sets slightly, continue with the main pour. Use hand tools or laser-guided screeds to keep the level consistent and avoid dragging across the pipes. This helps prevent pipe floatation and ensures accurate slab coverage.

5. 5

   Avoid Vibrating Directly Over the Pipe Runs

   While concrete vibration is essential for compaction, avoid using needle vibrators directly on top of pipe loops. Excessive vibration can dislodge pipe fixings, cause movement, or create pipe contact with mesh or rebar. Use perimeter vibration where possible, or vibrate beside (not on top of) the zones. On deeper pours or reinforced slabs, consider using surface vibrators or laser screed systems with built-in compaction to reduce risk to the pipe network.

6. 6

   Mark Manifold and Pipe Entry Points Clearly

   Where pipes enter walls or manifolds, mark and protect those entry zones with foam sleeves, conduit, or insulation wrap. These entry points are prone to being stepped on or knocked during finishing. Use high-vis tape or signage around manifolds to warn workers. You can also box off manifold locations temporarily to prevent accidental knocks while working concrete nearby.

7. 7

   Re-Check Pipe Position Before Final Finishing

   Just before the final trowel or float pass, re-check that no pipes have lifted or shifted. Use a laser level or depth stick to confirm slab depth across multiple zones. If any pipe sections appear closer to the surface than intended, gently push them down with a screed bar before the mix sets. Ensuring all pipes are fully submerged to the correct depth is essential for both durability and heating performance.