The short answer
Purpose-made flood products work better than sandbags, but none makes a home flood-proof. The Environment Agency says sandbags are relatively ineffective compared with purpose-designed products: they take time to fill, are heavy, and seep water even when stacked well. It encourages flood boards, non-return valves for drains and air brick covers instead. Water can also get in through air bricks, drains and cable entries, so a door barrier on its own isn't enough. Check your flood risk first, ask your council about its sandbag policy before a flood, and ask your insurer about Flood Re's Build Back Better scheme if you've already flooded.
The short answer
Purpose-made flood products help. Sandbags help less. Nothing makes a home flood-proof.
The Environment Agency's sandbag leaflet says sandbags are relatively ineffective when compared to purpose-designed flood protection products, and it strongly encourages flood boards, non-return valves and air brick covers instead. Fareham Borough Council, which points residents to tested products, adds that such products alone will not make a home flood proof.
First, check whether you're at risk. In England, GOV.UK's long-term flood risk service shows risk from rivers, the sea, surface water, reservoirs and groundwater for an area (not a single house). Our flood risk guide covers Wales, Scotland and Northern Ireland too.
Sandbags vs barriers vs other products
| Option | What it does | Good points | Problems | Source |
|---|---|---|---|---|
| Sandbags | Block doorways, weigh down drain covers | Cheap; filter some mud | Slow (about an hour to fill 12), heavy, seep water, soak up sewage, rot if left | Environment Agency |
| Door flood barriers / flood boards | Fit across a doorway | Faster than sandbags; recommended over them | Only cover the door | Environment Agency; GOV.UK |
| Flood doors | Replace a normal door | Always in place | Cost; fitted by a builder | GOV.UK |
| Air brick covers or self-closing air bricks | Stop water coming through vents in walls | Deal with a common way in | Covers must be fitted in time | GOV.UK; Be Ready |
| Non-return valves | Stop floodwater coming up through drains and toilets | Water often enters this way | Fitted by a plumber | GOV.UK; Environment Agency |
We don't give product prices: costs vary a lot by home and we didn't find an official price guide.
Water gets in more ways than the front door
The Environment Agency says to consider all entry points, not just doorways: air bricks, where pipes and cables come in, and other gaps. It suggests silicone sealant where sandbags won't work. GOV.UK suggests non-return valves to stop water coming in through the drains.
That's why a single door barrier often disappoints. A professional survey looks at every way in.
If you do use sandbags
The Environment Agency's own advice:
- Don't assume the council will give you any. Ask about its policy before a flood. There may be a charge, and stocks run short.
- You need at least 6 sandbags to keep out 20 cm of water at a standard door, each with about 15 kg of sand. A wall 60 cm high and 1 metre long takes about 80.
- Fill them no more than half full. It's a two-person job.
- Lay them like bricks, each layer overlapping the one below by half, and stamp them down. Plastic sheeting behind them helps.
- In an emergency, pillow cases or bin bags filled with garden soil can stand in.
- Sandbags are no use once water is already inside. Then concentrate on keeping yourself safe and moving precious things upstairs.
- After a flood, sandbags hold contaminants such as sewage. Ask your council's environmental health team how to get rid of them.
Note: this leaflet is from March 2009, but it's still on GOV.UK and it's the Environment Agency's most specific advice on sandbags that we found.
Buying products: what to check
- Look for tested products. Fareham Borough Council says approved flood products are Kitemarked, after testing involving the Environment Agency and HR Wallingford. Ask the seller which standard a product was tested to.
- Use the code of practice. CIRIA's Code of practice for property flood resilience (2021) sets out six standards for what property flood resilience work should achieve. Ask any surveyor or installer whether they work to it.
- Get advice. Be Ready points to Flood Mary, a free advice site with guides and a product directory.
- Check permission. GOV.UK and Be Ready say you may need permission for work that affects the flow of a river or diverts floodwater.
Help with the cost
- Flood Re's Build Back Better. If your home floods and your insurer offers it, Build Back Better can pay up to £10,000 for flood resilience measures, such as flood doors and non-return valves, as part of repairs. It's offered through participating insurers, so ask yours, ideally before you buy a policy.
- Government grants after named floods. Past property flood resilience grants have paid up to £5,000 per property, through councils, for specific flood events (for example the November 2019 floods and Storms Ciara and Dennis in 2020). These rounds open and close with particular floods. If you've flooded, ask your council whether one is open.
- No insurance? Be Ready says contact your council about hardship grants or charities.
Our post flood ready: before, during and after explains Flood Re and insurance.
Products are one part of a flood plan
Barriers buy time. The rest of the plan matters as much:
- Sign up for flood warnings and know what each level means: see flood warnings explained.
- Pack a grab bag with documents in a waterproof wallet, medicines, a torch and a power bank: see how to make a go bag.
- Know when to leave. Never walk or drive through floodwater. See stay put or leave?
What to buy
About these links: plain links to ordinary retailer pages. We may earn from some links in future; we don't now. We haven’t tested these and we don’t rank them: they are examples that were in stock when we checked. Prices change. Check what you already own first. Full kit list
Torch or head torch, plus spare batteries
Look for: Runs on the same AA or AAA batteries as your other kit, so one spare pack covers everything. A head torch leaves both hands free.
- Alpkit Ionic 350 Lumen Head Torch · Alpkit · £15.99 (price on 1 November 2026) Shop
- Lifesystems Intensity 155 LED Head Torch · Lifesystems (UK brand store) · £19.99 (price on 1 November 2026) Shop
- Alpkit Kula 550 Lumen Head Torch · Alpkit · £19.99 (price on 1 November 2026) Shop
- Lifesystems Intensity 480 LED Hand Torch · Lifesystems (UK brand store) · £29.99 (price on 1 November 2026) Shop
- Dynamo Powered Wind-Up Pocket LED Torch · EVAQ8 · £3.60 (price on 1 November 2026) Shop
Power bank
Look for: From a seller you know. Check the capacity (mAh) against your phone, and that you have the right cable for each phone. Keep it charged.
Waterproof document wallet or resealable bags
Look for: Big enough for copies of passports, insurance details and medicine lists.
- Waterproof Document Pouch - Translucent PVC · EVAQ8 · £5.11 (price on 1 November 2026) Shop
What we couldn't check
- We couldn't open the BSI standard for flood products, so we don't name a standard number. Ask the seller which test a product passed.
- We found no official price list for flood products or surveys, so this page gives no costs.
- Grant rules change with each flood event. The £5,000 figure is from past rounds; check with your council.
- Flood Mary is an independent advice site run by a flood resilience campaigner, not a government body. Be Ready links to it.
Frequently asked questions
Do flood barriers work?
Purpose-made flood barriers, flood doors, air brick covers and non-return valves can reduce how much water gets into a home, and the Environment Agency recommends them over sandbags. But they don't make a home flood-proof: water can come through walls, floors and drains. Use them as part of a plan that includes warnings, moving valuables and a grab bag.
Do sandbags work?
A little, for a short time. The Environment Agency says they can keep water out for short periods, especially with plastic sheeting, but are relatively ineffective compared with purpose-made products. They take about an hour to fill 12, need two people, seep water and soak up sewage from floodwater.
How many sandbags do I need for a door?
The Environment Agency says at least 6 sandbags to keep out 20 cm of water at a standard door, each with about 15 kg of sand. Fill them only half full and lay them like bricks, overlapping by half.
Will the council give me sandbags?
Don't count on it. The Environment Agency says don't assume the authorities will provide sandbags, and that protecting your property is the owner's responsibility. Some councils keep a small stock. Ask your council about its policy before a flood, as there may be a charge or limits.
Is there a grant for flood barriers?
Sometimes, after a specific flood. Past government property flood resilience grants paid up to £5,000 per property through councils, for named flood events. If you've flooded and are insured, ask your insurer about Flood Re's Build Back Better scheme, which can pay up to £10,000 for resilience measures during repairs.
Sources
We opened each page on the date shown. Official advice changes: if a source says something different now, follow the source.
- Environment Agency: Sandbags and how to use them properly for flood protection (leaflet, March 2009, PDF) (read 2 November 2026)
- GOV.UK: Prepare for flooding, protect your property (read 2 November 2026)
- GOV.UK Be Ready: flooding (read 2 November 2026)
- GOV.UK: Check the long term flood risk for an area in England (read 2 November 2026)
- Fareham Borough Council: Sandbags (read 2 November 2026)
- CIRIA: Code of practice for property flood resilience (C790F, January 2021) (read 2 November 2026)
- Flood Re: Build Back Better (read 2 November 2026)
- Defra (GOV.UK): Government extends £5,000 grant scheme for flood-hit homes (21 September 2020) (read 2 November 2026)
- Flood Mary (property flood resilience advice, recommended by Be Ready) (read 2 November 2026)
Related guides
- Check your flood risk, and the other risks where you live
- Storm and flood preparation in the UK
- Flood alerts and flood warnings: what each level means and what to do
- What to do after a flood: a calm, step-by-step guide
Free tools
We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.
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