Roof leak tracing in Christchurch: finding water before you re-sheet

Water runs down underlay, along purlins, and across ceiling battens until it finds a hole in the gib. The brown patch you see is often the exit point, not the entry point.

Patching the sheet directly above the stain feels logical and sometimes works by luck. More often the real fault sits at a valley, a chimney step, or a screw line on a different elevation that only leaks when the wind blows from the northwest.

We start with your story. Does it leak in steady rain, only in wind, or when the valley overflows? Each pattern narrows the search.

On the roof we follow lap direction, check upslope flashings, test fixings, and inspect valleys and penetrations. Inside the ceiling space we look for water tracks on timber, rust on screws from below, and daylight through torn underlay.

Failed pipe flashings on older vents crack in UV and let slow drips through. Chimney aprons lift in nor'westers. Skylight head flashings dam debris on north-facing slopes.

Nail-fixed iron with popped heads lets water in through the fixing hole in the sheet. That is the entry point we trace on re-screw call-outs.

Not every damp ceiling is a hole in the roof. Poor ventilation, uninsulated ceilings, and cold nights can produce moisture that looks like a leak but dries when weather warms.

We distinguish the two before quoting re-sheeting. Tracing saves you from replacing sound steel when the fix is ventilation, underlay, or a single flashing detail.

Once the source is confirmed, we repair with formed metal and correct fixings, not a tube of sealant from ground level. If the steel around the fault is perforated or the roof is end of life, tracing still tells us which slopes actually need replacement.

Bring photos of stains after rain and note wind direction if that matters. That context speeds the search and gets you a permanent fix faster.