Drainage
The fixtures and everything that takes their water away: waste and soil pipes, vents, chambers, buried drains and rainwater. 38 fittings, every drain laid at its fall, and each chamber as deep as the drains running into it.
Every property, and what it does
Select a drain or a fitting and these are its rows. A band shows when it applies, so a drain has its fall and a chamber its cover level and invert.
The catalogue
The fixtures and fittings, by the system they are on.
| Field | What it does | Values |
|---|---|---|
| Waste | The waste fittings, each with its plan symbol and its usual mounting height. | Wash hand basin, Bath, Shower, Kitchen sink, Utility sink, Washing machine connection, Dishwasher connection, Bidet, Urinal, Trap, Floor trap, Floor waste, Waste disposal unit, Grease interceptor |
| Soil | The soil fittings, each with its plan symbol and its usual mounting height. | WC, Septic tank, Cleanout |
| Vent | The vent fittings, each with its plan symbol and its usual mounting height. | Vent terminal, Vent stack, Air admittance valve |
| Drainage (below ground) | The drainage (below ground) fittings, each with its plan symbol and its usual mounting height. | Inspection chamber, Manhole, Inspection pit, Sump, Formed duct, Rodding eye, Sump pump, Submersible pump |
| Surface water | The surface water fittings, each with its plan symbol and its usual mounting height. | Gully, Soakaway, Drainage trench, Petrol interceptor, Cyclonic separator, Oil interceptor, Gully sump |
| Rainwater | The rainwater fittings, each with its plan symbol and its usual mounting height. | Downpipe, Roof drain, Rainwater hopper |
Element
What the selected run or fitting is, and which trade it belongs to.
| Field | What it does | Values |
|---|---|---|
| What it is | The catalogue name of the fitting, or the kind of run. | Read from the element |
| Kind | The catalogue entry it was drawn from. Change it to swap the fitting, keeping where it sits. | The 38 fittings of the trade |
| System | What it carries. It decides which trade owns it, its colour and its schedule. | Waste, Soil, Vent, Drainage (below ground), Surface water, Rainwater |
| Trade | The trade that owns it, read from the system. To move it, change the system. | Read from the system |
| Supply | Whether a fitting that needs a supply is connected to one by a run. | Connected, Not connected, Not required |
Design
Sanitary fixtures, traps and chambers are drawn from their own design, so the symbol and the body follow it.
| Field | What it does | Values |
|---|---|---|
| Preset | A named design for the fitting. Change anything in it and it reads as modified. | The fitting's named designs |
| Design controls | The parts of the fitting itself, drawn from its own generator, so its symbol and its 3D body follow. | By fitting |
| What that makes it | What the design comes to, read only, so the schedule cannot disagree with the fitting. | Contents, Internal, Depth, Excavation, Clear cover, Capacity, Minimum at this depth |
Fall
A drain falls from its start, and its levels follow from that.
| Field | What it does | Values |
|---|---|---|
| Gradient | The drain's fall, as 1 in n. Blank for a run that does not drain. | 1:n |
| Set to fall | Lays a drain drawn level at its usual fall from its start. | One click |
| Branch fixes | Where a branch would arrive below its main, re-lays the main deeper or splits it with a drop, one edit each. | One click |
Chamber
An inspection chamber or manhole, set from the ground and the drains running in.
| Field | What it does | Values |
|---|---|---|
| Cover level | Where the ground is, in metres. The only one of the three you set. | Metres |
| Invert | The bottom of the chamber, from the gradient of what drains into it. | Read only |
| Depth | Cover level less invert. Move a chamber further away and it goes deeper, because the fall is held. | Read only |
| Minimum size | The smallest chamber allowed at this depth (Approved Document H1 Table 10). | Read only |
Rainwater
A gutter is graded by the roof that falls on it.
| Field | What it does | Values |
|---|---|---|
| Falls on it | The roof area that drains to this gutter (BS EN 12056-3). | From the roof's pitched area |
| Takes | What this size of gutter carries, half round and level to an outlet at one end. | Read only |
| Downpipe | The downpipe this size of gutter discharges through. | Read only |
Size
The size of a run, and how the plan draws it.
| Field | What it does | Values |
|---|---|---|
| Nominal | The diameter of a round run, or the larger side of a duct. | Pipe sizes in mm, from the trade's usual size |
| Shape | Round, or rectangular with a width and a height. | Round, Rectangular |
| Drawn as | Runs 75 mm and over are drawn to their width with two lines; smaller ones as a single line. | Single line, Double line to width |
Where it runs, where it sits
A run has two ends and a level at each; a fitting has a height and a facing.
| Field | What it does | Values |
|---|---|---|
| Start, End | The fitting each end is bound to. A bound end goes wherever the fitting goes. | Read from the plan |
| Level at start, Level at end | How high each end is above the storey's floor. | Millimetres |
| Invert at start, Invert at end | The level of the inside bottom of the pipe at each end, for runs that fall. | Derived from the run it leaves and its gradient |
| Length in plan | The run's length on the plan. | Read from the plan |
| Drop | How far the run falls from start to end. | Derived from the two levels |
| Height | How high a fitting stands above the storey's floor. Negative is below ground. | Millimetres; each fitting starts at its usual height |
| Facing | Which way a fitting faces, anticlockwise from east. 90 faces up the page. | Degrees |
| Flip to the other side | Moves a wall fitting onto the other face of its wall, pointing into the other room. | One click |
Belongs to
What the schedule files it under, and whether a person has checked it.
| Field | What it does | Values |
|---|---|---|
| Circuit | The circuit or zone the schedule files it under. Where a fitting is wired, the wiring decides. | Any name |
| Proposed | Marks what a generator wrote and nobody has checked yet. Confirm clears it. | Confirm |
How the Drainage tools work
Open Drainage
In the editor, open CAD tools and choose Drainage. The group has three tools: Catalogue (DRAINAGE), Drain (DRAIN) and Place (PLACEDRAIN).
Place the fittings
Pick a fitting from the catalogue by its system and click where it goes. It stands at its usual height, which its panel can change.
Draw the drains
With Drain (DRAIN), click each point and press Enter. A run that starts or ends on a fitting snaps to its connection point and is joined to it.
Or generate them
Settings, Structure, Drainage runs the soil, waste and rainwater from the fixtures in named rooms out to the boundary that faces the street, marked as proposed.
Drainage questions, answered.
What can I place?
WCs, basins, baths, showers, sinks and appliance connections, traps and floor wastes, vent stacks and air admittance valves, inspection chambers and manholes, rodding eyes, gullies, soakaways, interceptors, downpipes and roof drains.
How are the levels worked out?
Each drain falls at its gradient from its start, so its inverts follow. A chamber's cover is the ground, its invert comes from the drains running in, and its depth is the difference.
Can it draw the drains for me?
Yes. The drainage generator runs soil, waste and rainwater from the fixtures in named bathrooms, kitchens and utilities to the street. It is a first layout to check and change.
Are the services in 3D too?
Yes. Runs are built as real cables, pipes and ducts at their levels, fittings stand at their heights, and a run that crosses a wall or a floor cuts its own hole through it.
Read on
- Plumbing and Heating: Water, heating and gas pipes.
- Site Boundary: The plot the drains run out to.
- Drainage docs: Falls, chambers, the generator and the checks.