Do sandbags stop flooding?

Are sandbags effective flood barriers? 

Sand bags may seem an inexpensive flood barrier to keep floodwater out of homes and businesses but sandbags are environmentally unfriendly and dealing with them is a laborious, back-breaking task that requires a lot of time and effort. They also cost a fortune to store or transport anywhere and they are virtually impossible to deploy quickly.

Pound for pound (or dollar for dollar) FloodSax alternative sandbags can be a more cost effective way of providing flood protection both outside and inside buildings. They are space-saving to store and quick and easy to deploy as highly effective flood barriers. 

So here it is in a nutshell, the great sandbags v FloodSax debate.



Must be replaced regularly costing thousands of pounds for big companies and local authorities that need sandbags on pallets ready all year round for any emergency.

Can deteriorate if stored for a long time, especially in cold, damp warehouses.

Exceptionally unwieldy to lift and handle with all kinds of health, safety and manual handling technique problems for staff who have to use them for flood mitigation at businesses.

Messy with the sand easily washed out and adding to all the damage if they burst. Sand also gets washed down drains, clogging them up and causing more flooding problems.

Difficult and expensive to transport anywhere due to their weight. One box of 20 FloodSax is equal to 20 sandbags on a pallet.

Need a lot of people to move any number of sandbags anywhere and then build them into flood barriers.



Easy to store and vacuumed-packed to save even more room.

Multi-purpose and flexible with dozens of uses so can be deployed both inside and outdoors, unlike sandbags. In their dry state, FloodSax can be slipped into hard-to-reach places such as beneath pipes and boilers to soak up leaks, drips and spills. Traditional sandbags are, well, just sandbags for outdoor use only.

Always there for peace of mind. No panic to buy sandbags if a flood is forecast and when that happens you'll find that sandbags are often difficult and expensive to buy prefilled and will take hours to fill your own.

Can be expanded in water right next to where you need them and stay taut until the flood subsides so are ideal as strong and robust flood barriers.

Lightweight before they are used with the standard bag weighing just 0.2kg (7 ounces) so can be used by people who would not be able to lift sandbags

Hundreds can be quickly transported in a van, saving on fuel, wages and manpower. Around 35 boxes with 20 FloodSax in each can fit in a van. That’s 700 Floodsax in all and the same amount of traditional sandbags would weigh 14 tonnes and need lorries to transport them.

Can be stored in small depots around the area, not one huge central store so can be taken even more quickly to the scene.

One can be expanded and put down the toilet to block it from filthy water being forced up by the floodwater backing up through the drains and sewer.

FloodSax don't need sand - one of the earth’s natural resources - and so saves the environment.


Frequently asked questions about sandbags

How else are FloodSax known? Although FloodSax is the trade name people refer to them as floodbags, floodsacks or waterbags. 

Where would you store sandbags? They will take up a lot of space and would need heavy duty racking to hold them so ideally they need warehouses.

Are sandbags biodegradable? The answer is a resounding no. They take up one of the earth’s valuable resources – sand – but there is no easy way to get rid of sandbags once they’ve been used.

Can sandbags be reused after they have been deployed as flood barriers? Again, it’s a clear no as just about all floodwater is contaminated so once they’ve been used for flood mitigation you need to get rid of them to avoid potential health problems from all the bugs and nasties that are stuck in them from the floodwater.

And the biggest question of all. Do sandbags work to prevent flooding?

In the UK the Environment Agency - experts on floods and pollution - say sandbags have many pitfalls when it comes to flood defence and people should look to other products specifically designed to be fit for purpose when flooding strikes. One of these are FloodSax alternative sandbags.

The Environment Agency states: “Sandbags are relatively ineffective when compared to purpose-built flood protection products. We strongly encourage people to use these products.”

The Environment Agency report adds that sandbags:

* Do seep water even when well-stacked and trodden into place.

* It takes two people to fill them and around one hour to get just 12 sandbags ready.

* They can be difficult to handle and laying them can be very time-consuming.

* The outer material used to make sand bags will usually perish if left in place for a long time.

On top of this it’s hard to even get hold of sandbags as local authorities have no responsibility to provide them to homes and businesses when flooding is imminent.

The Environment Agency warns: “Don’t assume the authorities will provide you with sandbags in a flood emergency. It is the responsibility of property owners to take appropriate action to protect their property from flooding.”

In the USA, one local authority, Lewis County in Washington, admits sandbags won’t keep water out by themselves, saying: “Sandbags alone should not be relied on to keep water outside a building. Use baffle boards (plywood sheeting) or sheets of plastic tarp with sandbags.”

Lewis County also warns:

* Sandbags will not seal out water.

* Sandbags deteriorate when exposed for several months to continued wetting and drying. If bags are placed too early, they may not be effective when needed.

* Sandbags are not always an effective measure in the event of flooding because water will eventually seep through the bags and finer materials like clay may leak out through the seams.

In Australia, the Queensland Government’s Disaster Management advice states: “Sandbags will not stop the water completely. Do not over fill as they will be too heavy to carry.”

And they add: “Sandbags should not be reused if they have been in contact with floodwater.”

Traditional sandbags are made from coarse canvas known as Burlap woven from jute, hemp, or a similar fibre which means they can be prone to rotting.