The short answer
It can be, with some planning. Downpipes feeding a water butt are disconnected or diverted before work starts, so that moss, grit and any treatment product stay out of the stored water. A pond near the house is covered or kept clear of run-off. Tell us where your butts and ponds sit before the visit, and the ground gets planned around them.
Rain from the roof ends up somewhere. Where a butt or a pond collects it, a clean needs a plan for keeping the wrong water out.
Where roof water goes
A downpipe carries water from the gutter to a drain, a soakaway or, in many gardens, a water butt. The butt is a tank that stores rainwater for the garden. During a roof clean, everything that comes off the roof can follow the same route, and that is why the downpipes matter before any brush touches a tile.
What could end up in the butt?
Three things: moss and grit, rinse water, and traces of treatment product. Moss and grit are harmless to plants but foul the butt, clog the tap and settle as sludge. Treatment product is the more important of the three. Treatment products are made to kill moss and algae, so they have no place in water you plan to pour onto a vegetable bed.
Article 17(5) of the retained Biocidal Products Regulation holds every use to the authorisation behind the product. Reading that label tells us what may be applied and where run-off is allowed to go. We walk the downpipes with you at the start and mark which ones feed a butt, a pond or a soakaway.
Disconnecting downpipes and diverting run-off
The simplest fix is to take the butt out of the circuit for a while. Water-butt diverters, the plastic collars that sit in a downpipe and send flow to the tank, can be closed so rain goes down the drain instead. If the butt is plumbed in without a diverter, the pipe is lifted away or capped at the top.
Can the butt be protected without removing it?
Yes, in most set-ups. Closing the diverter or disconnecting the short pipe into the tank is enough, and a lid or a sheet over the butt keeps falling debris out. For a freestanding butt under the eaves, we move it away from the wall or cover it fully. A butt that is already full is better emptied beforehand, as there is nowhere for any extra water to go.
Gutters are cleared once the moss is off the roof, and the downpipes run through to confirm they are open. Only then is the butt reconnected, and we tell you when it is safe to do so, which is normally after rain has flushed the system through.
The separate answer on moss in gutters covers the part of the job that sits just above the butt.
Ponds, fish and other water
A pond is more sensitive than a butt, because living things sit in it all day. The aim is to keep the run-off out entirely.
What do we do near a garden pond?
If the pond sits beneath or beside the roofline, it is covered with a sheet held clear of the surface, or the work on that side is done by hand with the debris bagged. Where the roof drains by a pipe into a pond, the pipe is disconnected and led away for the day. Tell us if you keep fish or have a wildlife pond, so that the plan can fit what lives there.
The rules on products back this up. HSE's position is that professional-only treatments are not for householders, and the label of any product sets out where it must stay out of. A pond is on that list for many of them.
Streams, ditches and field drains need the same thought. Somerset has plenty of rhynes and ditches near houses, so tell us if one runs beside your property.
Putting the garden back to normal
When the roof is finished, the garden should work as it did before, with no sign of what has been done.
When can I use the water butt again?
Once the roof has been rinsed by a decent fall of rain and the gutters and downpipes are clear, the diverter can be reopened. We say when that is, and we do not advise drawing water for edible plants until the first flush has gone through. If the butt is a source of drinking water for animals, wait longer and check the label of whatever was used.
It is worth looking at the tap, the lid and the inlet after reconnection. A bit of grit in the bottom is normal and can be flushed out. If water looks cloudy or smells odd after a week, empty it and let the next rain refill it.
For wider questions about the work, the roof cleaning and moss removal page lists everything we cover, and our answer on garden damage from roof cleaning looks at the beds and lawns.
Send us a photo of your downpipes and any butts or ponds. The survey that follows gives you one written total, with the water protection already planned in.
Butt and pond questions
Do I need to empty my water butt before a clean?
It helps. A full butt has no room for extra water, and a half-empty one is easier to cover or move. Disconnect or close the diverter first, whether it is full or not. We check the downpipes with you before starting and mark which pipes feed a butt.
Is butt water safe for the garden after a roof clean?
Give it time. Once the diverter is reopened, let the first heavy rain flush the gutters and downpipes before you draw water for edible plants. If a product was used, its label sets any waiting period, and we pass that on to you when we hand over.
The full picture: Roof cleaning and moss removal in Taunton ยท More short answers