Last reviewed: Oct 2018

For more information visit: www.thefloodhub.co.uk

@TheFloodHub

Property FloodResilience (PFR)

Booklet

This resource has been produced by Newground who work in partnership with the

Environment Agency

Last reviewed: September 2021

Flood barrier / Lakeside Flood Solutions

INTRODUCTION

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Property Flood Resilience (PFR) is the term used to describe the ways in which aproperty can be protected from flood damage. The two main strategies used are

‘resistance’ and ‘resilience’.

Flood Resistance

Flood Resilience

A flood 'resistance' approach aims to prevent water entry or reduce the amount offloodwater that enters a property and it requires the purchase and installation of homeflood defence products. These products can be permanent or temporary. Permanentproducts are fitted, left in place, and remain 'always ready' to work 24/7, with no actionneeded to activate them in the event of a flood. Temporary measures are usually storedaway and then put in place when flooding is expected.

Government guidelines suggest 600mm (2ft) as a safe height to resist water entry, butmany buildings in flood risk areas are protected to around 900mm (3ft). Beyond this height,it is advised that floodwater should be allowed to overtop barriers and enter a property toprevent structural damage.

A successful resistance strategy ensures that every water entry point on the property isprotected. If a single point is missed or a flood defence product fails, the property will beginto take on floodwater which compromises all other protection measures and results in afailed package of works.

A flood ‘resilience’ approach aims to reduce the damage caused by floodwater when itenters a property, resulting in quick and easy cleaning, drying, recovery and reoccupationof the property. This could potentially eliminate the need for an insurance claim. Resilientmeasures usually involve changes to the fabric of the building so no action is needed toactivate them in the event of a flood. Undertaking a resilience approach directly after yourhome has flooded presents an opportunity to reinstate the property with water resilientmaterials and design.

Things to Consider

Understand your Flood RiskFlooding can occur from rivers, ordinary watercourses, surface water, groundwater, sewers, andreservoirs. Understanding your flood risk and where floodwater may affect your property from isimportant for identifying the most appropriate strategy for protecting your home.

Professional AdviceWhilst not mandatory, a property flood resilience survey by an experienced professional would beadvised if you are unsure about how to proceed in protecting your property. There will be acharge for a thorough survey and report, which help you make informed choices when choosingresilience strategies.

Property TypeIf your property is a listed building, or is located within a conservation area, certain products suchas PVC flood doors, or exterior works such as re-pointing or rendering may have additionalrequirements or not be permitted.

Kitemarked ProductsThe BSI (British Standards Institute) Kitemark for Flood Protectionproducts is BS 851188, meaning the products have been independentlytested under specific flood conditions. Any flood protection productsused by you or a contractor should be Kitemarked where possible.

MaintenanceMany PFR products require maintenance and cleaning to ensure they continue to work. You cancheck with the manufacturers product information as some installers may offer maintenanceservices. Annual servicing may be required in order to maintain the warranty and guarantee ofcertain products.

It is recommended that you make a regular maintenance schedule which includes testingproducts, such as with ‘wet runs’ for pumps.

Mark of trust / BSI group

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Flood doors are available in a wide range of sizes,designs, colours and finishes, including uPVC,composite, hardwood as well as steel and securitydoors for commercial premises. Appearance wise,flood doors can look the same as standard,ordinary non-flood doors. When closed and thelocking system engaged, a watertight seal iscreated between the door and its frame.

Flood windows work in much the same way andcan be used to replace basement windows orwhere floodwaters can reach significant depthsand the height of ground floor windows fall withinthe property’s safe standard of protection.

Flood doors & windows

Offer round the clock protection.Can restrict entry and exit in the event of aflood.Good option for elderly or disabled residentsor those who may be away from the propertyfor extended periods of time.Requires annual servicing and maintenance tomaintain the doors warranty and ensure itworks as intended during a flood.

Considerations:

Est. Costs: Starting at around £1,800 (Incl. VAT)for a single uPVC Flood Door includinginstallation. French doors, composite, hardwood,and bespoke designs will cost more.

Flood barriers can be fitted to external doorwayentrances and windows, garages, gardengateways and driveway entrances. Most work byhaving panels slotted into channels which remainpermanently installed on the doorway. Thechannels can be installed on the face of theentrance or within the doorway reveals.

Barriers come in a range of materials includingaluminium and uPVC. When not in use, colour-matched channel covers can be used to hide thechannels and protect rubber seals.

Some barriers are designed to be installed withinthe doorway reveal on inwards opening doors andwithout the need for channels, and they expand tocreate a seal with the floor and masonry.

Flood barriers

Maintenance required of rubber seals whichmay perish over time and need replacing.Barriers boards need to be stored correctly toavoid damage to rubber seals.Property owners need to be physically able tocarry out installation when a flood is expected.Barriers can close off access to and from theproperty on doors that open outwards.

Considerations:

Est. Costs: £500 - £800 for a single doorwayaluminium barrier, wider barriers at an increasedcost.

Flood barrier / Lakeside Flood Solutions

Affordable solution for air bricks or small holes.Relatively easy to install but must be installedcorrectly.Must be installed when flooding is expectedand removed once floodwater has receded.Adhesive patches designed for single use only.

A lower cost option to automatic air bricks are airbrick covers which can be placed on top of existingtraditional air bricks when flooding is expected.Most work by pre-installing a frame around the airbrick which the cover is clipped onto.

Self-adhesive patches can also be applied. Kits areavailable which include air brick patches andpatches that are designed to help seal aroundpipes or other small apertures in an emergency.

Considerations:

Est. Costs: £30 for a single cover and £20 for apack of 2 adhesive patches.

Offer round the clock protection.Require maintenance and cleaning.

Automatic (self-closing) air bricks are designed toreplace traditional air bricks, allowing air flow undernormal conditions and self-closing when they comein to contact with floodwater. The cartridgescontain floating balls which rise with floodwater tocreate a watertight seal, preventing water fromentering the wall cavity and flooding the property.Two units can be stacked to replace a double airbrick. They are available in different colours tomatch brick work and masonry.

Considerations:

Est. Costs: £60 (Incl. VAT) for a single unit, andaround £90 including installation.

Automatic air bricks Air brick covers

Prevents build-up of moisture within the cavity.Requires maintenance and cleaning.

Est. Costs: £4-10 per valve.

One-way weep valvesWeep holes provide an outlet for moisture thatcondenses within the cavity to drain away, but theyalso allow floodwater inside. One-way weep holevalves work in a similar way to NRVs and aredesigned to allow condensation to escape, andclose off under flood conditions to preventfloodwater from entering the cavity.

Cheap and easy to install.Considerations:

Air brick exploded view / StormMeister Air brick cover / The Flood Company

Weep hole vents / M3 Global Floodtec

A close inspection of all external wall / floorjoins and masonry is required.Listed buildings may require sampling/testing ofexisting mortar to create a match for re-pointing.On some older properties, a lime mortarspecialist may be required.

Gaps, cracks or holes in brick or stonework can berepaired with a water-resistant mortar. Similarly,any gaps in the wall-floor join of external walls canallow water into the foundations or sub-floor areasof the property.

Considerations:

Est. Costs: Will vary.

Easy to apply with a brush, roller or sprayapplicator.Dry to a natural finish.Odourless.Allows masonry and mortar joints to breathewhilst resisting water.

Different types of brick / stonework and mortar hasvarying degrees of porosity which, when in contactwith floodwater, can absorb water into cracks andfissures. The application of suitable waterproofingwall sealant, such as a silicone or siloxane waterbased sealant, can drastically reduce water ingressand even prevent it altogether.

Considerations:

Est. Costs: Will vary depending on the size ofproperty.

Wall re-pointing, sealants & rendering

Re-pointing External wall sealants

Water-resistant wall renders can help to slowdown water penetration or prevent ingressaltogether. Rendering from ground level upwardsmay not be enough in some cases, and theexcavation of soil and earth to render sections ofwall below ground may be needed. Renderingabove any damp proof course may lead to dampproblems within the home.

Wall rendering

Not suitable for all properties and planningpermission may be required.Seeking professional advice is recommended.Can be very effective.

Considerations:

Est. Costs: Will vary.

Repointing / The Spruce

Silicone sealants will perish over time andneed renewing.A thorough inspection around the property isrequired to ensure all entry points areidentified.

Holes can be found within masonry forwastewater outlet pipes, utility pipes and cables,aerial and satellite cables, telephone cables etc.Re-pointing mortar and silicone sealants can beused to close off these entry points to preventfloodwater entry. Adhesive patches can also bepurchased to wrap around pipework in anemergency situation.

Considerations:

Est. Costs: £15 - £40

Provides 24/7 round the clock protection.A made-to-measure solution may be required.Regular inspection and replacement of sealantaround the frame and door seals is required.

Standard meter boxes are not watertight, withgaps in the frame and holes for supply pipes andcables to enter the property. External gas, electricand water meters that come into contact withfloodwater will need water entry points sealed.

In most cases, the meters themselves belong tothe utility service provider, but the housings inwhich they are located belong to the propertyowner. Flood-proof meter box covers areavailable, or you can contact your service providerto discuss replacing the housing.

Considerations:

Est. Costs: £450 +VAT including installation.

Appliances must not be used when cover is in place.Not suitable for all appliances.Maintenance of seals is required.

Vent covers protect air vents and vents for some appliances such as tumble dryers. They comprise of asurrounding frame which remains permanently in place, and the cover is clipped in place when floodwateris expected to create a watertight seal. Specialist advice and guidance must be sought when looking toprotect a vent or flue for a gas or fuel burning appliance.

Considerations:

Est. Costs: £60 – £80

Gaps around pipework & cableentry points

Utility meter housings/covers

Vent covers

Vent covers / Floodguards

Permanently protect against the backflow offoul water, foul smells and rodents 24/7.Large NRVs can require some externalexcavation for installation.Flap gates installed within the chamber can bea quick and more affordable solution.With NRVs installed, toilets should not beflushed, and other appliances should not beused during a flood.Require periodic maintenance, cleaning, andreplacement of rubber seals etc.

In bungalows or properties with ground floor toilets,foul sewer water can back up (surcharge) from themain sewer system via the soil pipe and emergeout of the toilet, flooding the home internally. Watercan also back up through other bathroom andkitchen appliances to cause internal flooding.

Waste pipes can be protected from backflow withnon-return valves (NRVs) which can be installed in-line to the pipe itself where access is available.Where access is not available, they can beinstalled in-line between the toilet and theinspection chamber outside, though this requiresexcavation works.

Alternatively, one-way ‘push-fit’ flap gates can beinstalled within the inspection chamber itself toprevent foul water backflow into the bathroom.

Considerations:

Est. Costs: Small wastewater NRVs from £15 plusinstallation, flap gates from £25, and in-line NRVsfrom £200 plus installation.

Requires manual installation when flooding isexpected.Quick and easy solution with minimalinstallation.Pan seals are not designed to work with squaretoilet bowls.Regular testing and inspection for puncturemarks is recommended.

To protect properties against the backflow ofsewage and floodwater through the toilet wherenon-return valves cannot be easily installed,inflatable toilet pan seals and bungs offer analternative solution. Both products can be inflatedwith a standard bicycle tyre type pump.

Pan seals are designed to work with oval shapedbowls and are placed into the bowl and inflated tocreate a watertight seal beneath the rim of thebowl. Bungs are designed to be pushed down inthe U-bend of the toilet and inflated when in place.

Considerations:

Est. Costs: £40 - £50

Non-return valves (NRVs) Inflatable toilet pan seals / bungs

Non-return valve / drain depot

Toilet pan seal / JT Atkinson

Moving utility meters and re-wiring the wholeground floor can be complex and expensive.

Water, electricity, and gas meters and electricalsockets that sit within the level of floodwater onground floors are subject to damage whenflooding occurs. The meters, wiring and socketscan be raised or moved to a higher location abovethe anticipated level of floodwater to prevent futuredamage to electrical services. Electrics can alsobe wired from the ceiling downwards instead ofcoming up from under the floor.

Utility meters often remain the property of theservice provider, so it is recommended that youcontact them first to discuss moving the meter andensure a competent and qualified tradespersonundertakes the work.

Boiler units and ancillary devices should beinstalled above the predicted flood level andpreferably on the first floor of a building. Electricalequipment such as TVs or PCs should be installedabove the flood level by wall mounting or placingon raised cabinets.

Considerations:

Est. Costs: Dependant on the works needed.

Replacing hinges is a cheaper option toreplacing the doors themselves.Moving doors would need to be done beforefloodwater enters.

Replacing doors with hardwood or other water-resistant alternatives and replacing skirtingboards with a uPVC alternative reduces flooddamage as these materials will avoid absorbingwater or being warped. Following flooding theycan easily be cleaned and won't need to bereplaced.

Quick release hinges can be fitted to internaldoors allowing them to be lifted off their hingesand easily moved to a higher location whenflooding occurs.

Considerations:

Est. Costs: Quick release hinges £10-20.Hardwood doors £50-100. uPVC skirting boards£10-20 per board.

Raised utility meters and electrics Internal doors & skirting boards

Quick release door hinge / tttnet

Using water-resistant paints an easier option totiling.Extra consideration for the building fabric ofolder properties.

Waterproof wall boards such as dragon board,aqua board and magnesium oxide board are moreresilient to water than traditional gypsum-basedplaster boards. If using traditional gypsum plasterboards, installing them horizontally can reduce theamount of remedial work needed after flooding.Materials such as lime plaster or cement renderwith waterproof additive reduces the likelihood thatwalls will be damaged by floodwater.

Walls can be painted with water-resistant paints ortiled. Ceramic tiles and water-resistant grout shouldbe laid over sand or cement render, not gypsum-based plaster. Closed cell insulation is moreresistant to water than traditional insulationmaterials.

Considerations:

Est. Costs: Waterproof boards £5-10 per squaremetre. Water-resistant paints £20-30.

Water resilient internal walls & floors

Walls

Easily removable carpets and rugs can beused to keep comfort.Replacing flooring can be expensive.

Solid concrete, concrete-based stone, and ceramictiled flooring are resilient to floodwater and easy toclean. Wood effect tiles are also available. All tilesshould be laid on cement-based adhesive usingwater-resistant grout.

Replacing floorboards and joists with water-resistant, treated timber will reduce waterabsorption and allow the floor to dry out quicker,reducing rot and distortion. Installing a chemicaldamp-proof course below suspended timber floorminimises sub-floor condensation, preventingrotten joists and floorboards.

Considerations:

Est. Costs: Dependant on material used and sizeof flooring.

Floors

Helps for a quick recovery following flooding.Can look the same as "normal" kitchen units.May be expensive to replace all kitchen units.

Water resistant materials such as stainless steel,bio composite, hardwood, or waterproofconstruction board can be sued for kitchen units.These can easily be cleaned down followingflooding to avoid replacement.

Appliances such as fridges and washing machinescan be raised on plinths and electrics raised abovethe likely flood level. Baskets can be used to storekitchen utensils so they can be moved or takenupstairs when flooding is expected.

Considerations:

Est. Costs: Dependant on size of kitchen andmaterials desired.

Professional advice and installation arerequired.Tanking systems can fail if not installedcorrectly.Cavity systems are designed to be completelywaterproof, often guaranteed for 20+ years.Cavity systems are expensive and can besusceptible to damage from future alterations tothe room.

For basements experiencing damp and smallpuddles of water, applying a cementitious wettanking slurry to the floor and walls can help to sealsmall gaps and cracks and create a waterprooflayer.

Basements prone to significant flooding fromgroundwater that need to be made completelywaterproof can be protected by a cavity drainmembrane system. This is complex and involvesthe installation of a sump chamber with pumpsystem to the floor, drainage channels, and a cavitydrain membrane for the walls and floor.

Once in place, wall and floor insulation can beinstalled, followed by a range of finished wallsurface options.

Considerations:

Est. Costs: Expensive and dependant on size ofbasement.

Water resilient kitchens Basement tanking

Cavity drain membrane system / Preservation Treatments

Specialist advice and professional installation isrecommended.Servicing and maintenance required.Electricity supply can be cut off during a floodso a battery backup unit or a backup generatormay be needed for electric pumps.Great for dealing with groundwater flooding.

Sump & pump systems remove water that hasaccumulated in a collection sump. They are usuallyinstalled in basements and sub-floor voids and self-activate when water enters the sump pit. The wateris then pumped through a discharge pipe to theoutside of the building, with a non-return valve onthe discharge pipe to prevent backflow.

Pump systems reduce the amount floodwaterwithin properties and the length of time it remainsthere, reducing damage and helping to speed upthe cleaning and drying process. The size of thesystem will need to be large enough to cope withthe anticipated load and it is recommended that asuitable system is installed by a competentprofessional. The pump should be hard-wired on itsown circuit to prevent loss of power from a circuittripping out during a flood.

Considerations:

Est. Costs: £1,000 - £3,000

Sump & pump systems Puddle sucker pumps

Good to have as a failsafe or back up in theevent of water entry.Can be used as part of a package of floodresistance or resilience measures to helpremove minor water seepage and leaks.Need to be manually installed and operated.Only powered when in contact with floodwater.These units are designed to be run dry.

Submersible / puddle sucker pumps are stand-alone pump units which can be deployed to helpremove minor water ingress. Discharge hosesneed to be connected and placed through awindow, letter box, over a flood barrier etc.

Considerations:

Est. Costs: £150 - £300

Puddle sucker pump / National tool hire shops

Further Considerations

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It is worth noting that this list of property flood resilience options provides examples of the types ofproducts that can be used, and there may be different options available for your home or businessthat are not listed here. As a last resort if flooding happens unexpectedly and you are unprepared,the use of sandbags or alternative sandbags may provide some level of protection.

Flood alarmsFor properties close to rivers or watercourses, private flood level alarm systems can provide anaudible alarm warning when water levels are raised or flooding is likely to occur, which providestime to install temporary PFR measures.

Sustainable Drainage Systems (SuDS)These improve the drainage of rainfall and surface water that accumulates around buildings toreduce possible flooding. There are various SuDS options you can install on your property,including water butts and retention ponds. Find a link to our SuDS booklet below.

Relocation of important or valuable itemsSome things cannot be replaced as part of an insurance claim, so it is important that important orvaluable items such as photo albums, documents, certificates and antiques, are stored onshelving, within water-proof containers, or moved upstairs where possible.

Property Flood Resilience Toolkithttps://thefloodhub.co.uk/property-flood-resilience-toolkit/

An Introduction to Sustainable Drainage Systems (SuDS) booklethttps://thefloodhub.co.uk/wp-content/uploads/2018/09/An-Introduction-Sustainable-Drainage-Systems-SuDS-booklet.pdf

Know Your Flood Risk: Homeowners Guide to Flood Resiliencehttps://thefloodhub.co.uk/wp-content/uploads/2021/01/KnowYourFloodRisk-Homeowners-Guide-to-PFR.pdf

Explore our Knowledge Hub for many more flood related resources:www.thefloodhub.co.uk/knowledge-hub

Useful Links

3 For more information visit: www.thefloodhub.co.uk

@TheFloodHub

This resource has been produced by Newground who work in partnership with the

Environment Agency

Last reviewed: September 2021