On a flat roof, everything that matters disappears under the protection and the finish: the slope screed, the membrane, its upstands. The defect, for its part, waits for the first real rain to show itself — once everything is already covered. Here is why this package is the number-one failure point of houses, the sequence of operations that protects you, and the proof to demand through the PontBat app before anything gets hidden.
General information article: designing and building a roof is a job for qualified professionals.
A successful flat roof cannot be seen: it can only be proven. What protects you from the first winter is not the final finish, it is the rigour of the sequence — and the record showing that every invisible layer was actually built, then put to the test, before being covered.
The direction of the slopes, the position and number of the outlets, the height of the upstands against parapets and at thresholds: all of it is decided on the drawings, not on the slab. A forgotten outlet or a threshold set too low is paid for over years. The PontBat reflex: a roof plan approved and archived in the project file before the first pour.
The slope screed is the layer that leads water to the outlets. Badly oriented or uneven, it turns the roof into a basin: water stands, searches, and always ends up finding a way through. The PontBat reflex: the slope screed is checked and photographed before the waterproofing goes down — a puddle left after the rain is a warning, not a detail.
On a flat roof, water almost never comes in through the middle: it comes in at the edges — upstands against the parapets, door thresholds, the surrounds of outlets and penetrations. These singular points make or break the waterproofing, and once the protection is laid, the membrane can no longer be inspected. The PontBat reflex: every upstand, every singular point photographed through the app before covering, filed in the milestone's record.
The outlets are plugged, the roof is flooded, left to stand, then the ceilings and walls below are inspected. As long as nothing is covered, a repair stays simple; after the finish, it means demolition. The PontBat reflex: a water-test report filed in the milestone's record — without it, the roof milestone is not approved.
Then comes what shields the membrane from the sun and from foot traffic, and finally what shows. At acceptance, a roof is not judged by its finish: it is judged by its file — photos of the upstands, the water-test report, the independent inspection. The PontBat reflex: an acceptance that rests on the milestone's evidence, not on a visit in fine weather.
When you build from afar, the roof is the most treacherous package on site: any fault becomes invisible by the next day. Four mistakes come up again and again — and all of them surface in the first winter.
The site saying to remember — “ma tghattich qbal ma tjarreb”: cover nothing before you have put it to the test. In other words: do not waterproof your doubts. As long as a question stays open — a slope, an upstand, a test — nothing gets covered. On PontBat, this is not a proverb: the milestone is what enforces the rule.
Building from afar does not let you climb up and check for yourself. On PontBat, an independent expert — never paid by the company he inspects — examines the roofing package, and the milestone stays frozen until the inspection is compliant. The first winter has nothing left to teach you.
Four requirements to set from the quote onwards: they cost nothing to ask for — and a whole roof to forget.
Every upstand, every outlet surround, every threshold photographed through the app while it is still visible: timestamped images, filed in the milestone's record. Once the protection has hidden everything, the proof will remain.
A real flooding test, documented, with its written result. If the test left no trace, consider that it never happened — and let nothing be covered.
The roofing package has its own milestone: the matching payment is only released once the evidence is in the file and the inspection compliant. Covering too early stops being tempting when nothing is paid before the proof.
An expert who is not paid by the inspected company examines the slope screed, the upstands and the water test. From afar, he is your eyes on the roof — and his verdict conditions the milestone.
A dedicated milestone, photos of the upstands before covering, a water-test report, an independent expert: with full project management, all of it is handled for you — even thousands of kilometres from the site.