Underfloor heating pipe, laid out on your plan.
A browser tool for water-based underfloor heating. Draw the rooms, lay the loops, read the length of every circuit, print the sheets.
One room, from bare floor to a checked layout.
Mark it up
Walls, a door, the room. The grid on the floor is the mat the pipe will follow: you choose the cell and the offset from the walls.
Lay it
One click on the room. It is too big for one loop, so it gets two of similar length, each with its leads to the manifold. Pitch 20 cm.
Change it, and see what breaks
Tighten circuit 2 to 10 cm and it runs to 108.3 m. The check marks it on the plan the moment it happens, long before the pipe is bought.
The layout is a first draft, and yours to edit. Pick the corner a loop enters from, squeeze or move it, keep pipe out from under the kitchen units, draw a route point by point. A circuit you changed by hand is marked as manual, and the tool does not lay over it.
What goes to site is on paper.
A PDF with every circuit on its own sheet, drawn over the grid so the crew can see which line the pipe follows. One more sheet for the manifold and the leads. And a materials list.
| Circuit | Room | Pitch | Length |
|---|---|---|---|
| 1 | Living room | 15 cm | 62.4 m |
| 2 | Living room | 15 cm | 63.1 m |
| 3 | Kitchen | 15 cm | 68.2 m |
| 4 | Bathroom | 15 cm | 41.8 m |
| 5 | Bedroom | 15 cm | 65.9 m |
| Pipe in total | 301.4 m | ||
It runs in the browser.
No account and nothing to install. It opens from a link.
Projects are kept in your browser. The plan is not uploaded anywhere.
Once opened, it works without a connection.
A project saves to a file you can send or open on another computer.
It is a layout tool, and that is all.
No heat loss calculation. How much heat a room needs comes from elsewhere, and it decides the pitch.
No flow rates, pressure drop or W/m². It gives the lengths those calculations start from.
No sizing of the boiler, heat pump or pump. Everything before the manifold is outside it.
Water-based floors only. It does not lay electric mats or cables.
Before you lay pipe
How far apart should the pipes be?
Spacing runs from 100 to 300 mm centres. In a reasonably insulated home 150–200 mm is usual; 100–150 mm in a bathroom or along a heavily glazed wall. Closer spacing gives more output at a lower water temperature, so heat pump systems tend to be tighter. The planner lays at 10, 15 or 20 cm.
How much pipe will I need?
As a rough check, floor area divided by spacing: about 5 m per m² at 200 mm, 6.7 m at 150 mm, 10 m at 100 mm, plus the runs back to the manifold. The planner measures each circuit along the pipe, so you get the figure, not the estimate.
How long can one circuit be?
Trade figures put 16 mm pipe at roughly 80–100 m and 20 mm at about 120 m. Your pipe manufacturer’s figure comes first. You set the limit in the project, and every circuit over it is flagged.
Spiral or serpentine?
A counter-flow spiral puts supply next to return, so the floor is even from wall to wall. A serpentine is simpler to lay and suits narrow rooms, but the floor cools along the loop. The planner draws both, and a double serpentine.
Figures on this page are common trade values, given for orientation. Check your design against the pipe manufacturer’s data and the rules where you build.