The short answer
It depends on the product and on how it is used, and the label is the authority. Roof treatments are biocides, designed to kill living growth, so pets and children should be kept away during application and until the label says the surfaces are safe. Runoff onto lawns, beds and ponds is the main route to a pet. If an animal is exposed, contact a vet.
What the label governs
A roof treatment is a biocide, in other words a chemical meant to kill living organisms. Each approved biocide is authorised for particular uses, and the Biocidal Products Regulation holds users to the conditions of that authorisation. The label carries those conditions.
So the first answer to the pet question is on the product itself. A label states how to dilute and apply the product, what protective gear is needed, how long to keep people and animals away, whether rain within a set time matters and how to deal with spills and washings. It may also give first aid guidance. That label is the authority, and it can differ greatly from one product to another.
Some strong products are for professional users only. HSE guidance bars householders from using those, partly because the controls they call for are beyond a householder.
A responsible roofer reads the label for the exact product, uses it as directed and gives you the advice that goes with it. If a firm cannot name the product or tell you what the label says about pets, that is a poor sign.
No general verdict on animals is possible, because it depends on the product. What can be said is that it is a regulated chemical and should be handled as one.
Keeping pets and children away
The practical steps are simple, and most come from common sense plus the label.
- Keep pets indoors, or well away from the garden, while the treatment is applied.
- Keep them away until the label says the treated surfaces and ground are safe, or dry.
- Do not let animals drink from puddles, buckets, water butts or ponds near the work.
- Move bowls, toys, bedding and outdoor furniture away from the area below the roof.
- Keep children out of the working area, and away from ladders, hoses and containers.
Cats and dogs that roam need particular thought. Tell neighbours who may have outdoor pets, and close side gates where a pet might wander into the area.
Small animals, birds and fish are vulnerable to runoff. If you keep rabbits, chickens or a pond, tell the roofer before the job, so protection can be planned.
Water butts are worth mentioning. If gutters feed a butt, the treatment may reach it, and the water should not be used on plants or given to animals until the label and the roofer say it is safe. A roofer can disconnect the downpipe from the butt during the work.
After the job, ask what the label says about re-entry, and keep to it.
Runoff is the main risk to pets
For most households, the roof is out of a pet's reach and the real route is the water that comes off it. Rain carries the product from the slope to the gutter and down to wherever the downpipe drains, usually a path, a bed, a lawn, a soakaway or a drain.
A pet can lick wet paving, drink from a puddle or walk through it and lick its paws. Treated runoff on a lawn can be eaten with the grass. Ponds collect what drains into them.
That is why runoff is planned for. A roofer can cover plants and borders, put down sheeting, divert downpipes into a container or a drain as the label allows, and choose a time when no heavy rain is forecast. After the work, hosing paths with clean water may be advised where the label says so.
Our page on roof cleaning runoff goes through ponds, plants and drains in more detail. Our page on using moss killer on a roof deals with the do-it-yourself side.
If you notice a pet drooling, vomiting, lethargic or acting oddly after a roof treatment, do not wait. Call a vet at once, and have the product name and label to hand.
What we do about it
Before a treatment, we ask what pets, children and water features you have, and we plan around them. You see the product and its label, and hear in plain words what it requires: how long to keep animals away, what the runoff will do and how it will be handled.
Approved products are used to their labels, applied from safe access at low pressure. Marley advises against jet washing, and an unplanned jet would throw spray further too; the aim is to avoid it.
If the roof needs no chemical, you are told. Sound tiles with a light stain may only need a gentle clean, and moss that has not taken hold may only need clearing by hand. A treatment is used when it is the right tool, and not as a habit.
A single written total follows the survey, covering the cleaning and any protection the job calls for. The roof biocide treatment page explains how a treatment works, and the roof cleaning and moss removal hub covers the full service for homes near Farnborough and Fleet.
