Damp is a perennial downside for properties, particularly these cited in wetter areas. With the potential to trigger structural injury to your own home and trigger well being issues if the damp results in mould, damp proofing your own home is crucial to stop long term injury to your property and its residents.
Whereas newer properties are constructed utilizing tried and examined damp proofing methods that stop moisture ingress, older properties are notably susceptible to damp and might have extra advanced remedial measures to repair any issues.
However in relation to damp proofing prices, costs can fluctuate vastly. Right here we check out various choices and the way a lot every may cost a little.
Components affecting damp proofing prices
There are a variety of things that can affect your damp proofing prices:
- The extent of the damp downside
- What’s inflicting damp in your house
- Age of the property being renovated or prolonged
- Dimension of the realm that wants damp proofing
- Will you require a specialist contractor?
- What a part of your property is affected
Whereas there are per metre pricing fashions, these also can fluctuate relying in your area. Thomas Goodwin, property and development knowledgeable at MyJobQuote says the common price to damp proof your own home normally falls round £300-£2500.
“Nonetheless, relying on location and the complexity of the job,” says Thomas, “these primarily based in London also can count on to pay on common £30 – £70 extra per day for labour, than these owners in different components of the UK.”
That can assist you finances on your extension or renovation, we have put collectively a information to the most typical damp-proofing options and the potential prices.
Thomas Goodman has labored as a property and development knowledgeable for MyJobQuote for six years and has labored within the development trade for over twenty years. Thomas continues to work on constructing tasks, whereas additionally offering knowledgeable development and property recommendation to trade professionals and DIY fanatics.
Damp proofing prices – new and current buildings
Damp proof course
Each new construct or extension requires a Damp Proof Course (DPC). That is normally constructed from strips of plastic and acts as a barrier inserted into the material of the constructing to stop water ingress from the bottom upwards.
Put in on all new buildings, together with extensions, it’s usually laid at decrease ranges. Nonetheless, vertical DPCs are additionally used at roof stage if chimney stacks or parapet partitions kind a part of the general home or extension design.
The prices for putting in this in a brand new constructing or extension can be included in your general structural prices. In case you’re utilizing a amount surveyor to assist put together a invoice of portions, they are going to possible listing it as a priceable merchandise.
Price: Checkatrade says to permit £500 – £1500 for an commonplace DPC.
Damp proof membrane
You ought to be putting in each a humid proof membrane (DPM) and a humid proof course (DPC) when constructing from scratch. A DPM comes within the type of massive sheets of polythene or an identical materials and acts as a defend in opposition to moisture.
Because it’s wider than the plastic used in a DPC, it is primarily used on the underside or within flooring. For an efficient watertight seal there must be a lap of a minimum of 150mm between the DPC and DPM.
It will also be used outdoors to stop moisture seeping into concrete slabs.
Price: Permit upwards of £100 for a roll of DPM.
Black jacking
Generally known as liquid DPM, black jacking includes the appliance of a black bituminous paint to exterior partitions. It will also be utilized to inside partitions however solely beneath plasterboard, plasterwork or concrete.
It is usually used to repair minor damp issues on current partitions when renovating properties.
Price: Roofing Superstore have a 5 litre can of Everbuild Black Jack 901 Black Bitumen Paint for £22 incl. VAT
French drains
A type of land drainage, French drains are used to stop water logging and a build-up of extra of floor water. They include a trench dug at a gradient into the bottom, which is then lined with membrane, stuffed with mixture and in most cases a perforated drainage pipe.
They’re efficient in redirecting water away from a constructing’s basis. They’re additionally typically known as trench drains or land drains and will be constructed as a part of a brand new construction or to treatment an current downside.
Price: For a median french drain price, permit £45 – £90 per metre for labour and supplies.
Damp proofing prices – Renovations
In case you’re renovating a property with damp points and you’ve got recognized what causes damp, you’ll have found a failed DPC.
Douglas Kent, technical director on the Society for the Safety of Historic Buildings (SPAB) says that whereas reducing in a brand new DPC might remedy rising damp, it isn’t a technique beneficial for older buildings.
“Drawbacks embody doable main structural issues and potential injury to historic finishes internally. A brand new bodily DPC can also be unsuitable for randomly coursed partitions, properties with entry difficulties and may typically trigger deterioration of masonry beneath the damp proof course the place moisture is concentrated.”
As a substitute, Douglas advises there are a variety of different choices, though it is essential to analysis which one is correct on your property.
Douglas Kent is a chartered constructing surveyor specialising in constructing conservation and is technical and analysis director on the Society for the Safety of Historic (SPAB), the place he has labored since 2000. Douglas publishes and lectures recurrently on constructing conservation and has contributed to numerous radio and tv programmes. He has additionally renovated a listed property.
Chemical DPC
This includes impregnanting partitions with a chemical resolution by means of holes on the backside to create a water-resistant barrier. Though this methodology is broadly used immediately, it’s not all the time acceptable for outdated buildings.
You additionally must be conscious that drilling holes is inadvisable in flint and granite and it’s laborious to kind a correct barrier in rubble partitions with voids. As well as, holes can look unpleasant and typically trigger deterioration of the masonry beneath the damp proof course.
Price: The sort of DPC usually prices £195/m (together with replastering).
Ceramic tubes
With this methodology, holes are drilled to obtain porous siphons roughly 50mm in diameter that take up damp and evaporate it from every tube.
Whereas a preferred methodology, issues might happen in follow. Drawbacks embody salt accumulation within the tubes that will improve moisture and air-flow is usually insufficient. As well as, the tubes are generally set in laborious cement mortar which is unpleasant.
Price: Anticipate to pay round £125/m.
Electro-osmosis
This technique makes use of electrodes bedding within the wall with the intention of utilizing {the electrical} potential to scale back capillary rise.
“Whereas low-cost, there’s a dearth of proof that electro-osmosis is ineffective,” says Douglas Kent. “The system is never used immediately because of the adjustment of present wanted to match variations in damp alongside a wall, normally proving impractical.”
Magnetic subject
An Austrian product presently beneath trial within the UK claims to inhibit the passage of water up a wall by inducing a neighborhood magnetic subject. That is achieved non-invasively with a unit plugged into mains, usually within the loft.
Price: The estimated price is round £3,000/unit (one unit covers an average-sized home).
For extra info on how this damp proofing methodology works, watch this video from Core Conservation.
Tanking – primarily utilized in basements or cellars
Tanking slurry
“If you’re seeking to damp-proof masonry, brick, or concrete partitions, an excellent methodology is to use a tanking slurry on inside partitions,” says Thomas Goodwin.
“It is a waterproof coating that’s made up of cement and acts as a barrier between any damp particles and the construction of your own home. Tanking slurry is mostly utilized in basements, though it additionally works properly on higher flooring.”
For extra info, learn our article on tanking and making a cellar dry.
Price: For knowledgeable contractor count on to pay round £30-£60/m2
Tanking membrane
In keeping with the specialists at Permaguard, “tanking membranes are sheets of specifically designed plastic materials that act as a water-resistant barrier to guard partitions and flooring from water ingress.
“Produced from prime quality HDPE, they’re designed to face up to years of temperature fluctuation and publicity to water with out changing into worn or degraded. Tanking membranes are simple to put in onto damp partitions, making a small cavity to permit the wall to dry out.”
Price: A PermaSEAL 8 Clear 40m² Waterproof Membrane Equipment prices £206.40 incl VAT from Permaguard.
Waterproof plaster
In case you’ve fastened your damp downside and have inside partitions in want of replastering, as one other precautionary measure, it’s possible you’ll want to use a water-resistant plaster combine.
Price: Thomas Goodwin says the common price for this sort of work is round £200-£400 per room, relying on the dimensions of the room and your location within the UK.
Damp proofing air flow choices
Poor air flow will be one of many main causes of condensation and mold within the dwelling which left unresolved can result in extra severe points with damp.
Bettering the air flow inside your own home is subsequently important in the event you’ve recognized an issue and want an answer. Choices can embody including wall vents or utilizing the finest dehumidifiers for eradicating extra moisture from the air.
Different choices embody optimistic enter air flow methods or mechanical air flow with warmth restoration (MVHR) methods, each of which might enhance points with air high quality and damp.
Price: Will be as little as £20 for a Perma-Vent Condensation Management Vent from Permaguard as much as £259.99 for a Meaco 20L Low Power Dehumidifier.
A optimistic enter air flow might set you again round £1000, whereas a MVHR system for a 4 mattress home might set you again £3 – £4000 excluding set up. It is usually tough to retrofit an MVHR system making it much less of an choice for renovation or extension tasks.
Damp proofing paints and lotions
As soon as your damp concern has been recognized and handled, there are a variety of paints and lotions in the marketplace which you need to use to use an extra layer of safety.
Both geared toward stopping water ingress by means of exterior partitions, or combating the results of mould and condensation on inside partitions, it is essential to keep in mind that they are going to solely be efficient if in case you have fastened the foundation explanation for the issue.
Inside partitions
Specialists at Ronseal say anti-condensation paint is a superb selection for stopping condensation points on inside partitions as, “it incorporates components that create a layer of insulation to scale back the formation of water droplets on partitions.
The sort of paint is finest utilized in areas susceptible to excessive humidity, comparable to bogs, kitchens, or basements.”
For areas within the dwelling the place mould has been current, after you have recognized the trigger and handled the issue, in addition to guaranteeing you have adopted the precise strategies for eradicating mould from partitions, there are additionally anti-mould paints to assist stop the expansion of any remaining mould spores.
Price: Ronseal Anti-Condensation Paint presently retails at £36.19 on Amazon and Ronseal Anti-Mould Paint from Amazon is £18.27 for 750ml.
Exterior partitions
In case you’ve checked out how you can cease mould on outdoors partitions, you will know that what masquerades as mould is commonly algae.
Nonetheless, in the event you’ve been repointing brickwork, or repaired cracks or holes in your partitions that had been permitting water and damp into your own home, you may additionally be eager to use an additional protecting layer to them as a precautionary measure.
Obtainable as each liquids, paints and lotions, it is essential to make sure any product you apply is breathable in order that you do not develop a problem with much more mositure changing into trapped inside your partitions.
Price: Anticipate to pay £35 upwards for cream, £25 for a water sealant liquid and £20 for paint.
FAQS
What further prices do I want to contemplate?
Past the first damp proofing course of, there are subsequent prices that renovators ought to anticipate.
These embody duties like replastering partitions which have been broken by dampness, repainting, redecorating, and addressing the aftermath of the damp-proofing course of.
These duties not solely restore the property’s aesthetics but additionally make sure the damp proofing’s efficacy in the long term.
Additionally think about components comparable to scaffolding if you’re endeavor repairs to a chimney stack.
How a lot does a humid survey price?
If you’re unable to seek out the sources of your damp and wish to name in an knowledgeable. Checkatrade says prices will vary from round £200 for a 2 mattress flat, as much as £600 for a 4 mattress indifferent property.
Shopping for a home the place the survey has indicated damp?
Douglas Kent shares a last word of warning earlier than you begin worrying your damp proofing prices are about to escalate.
“Surveyors have a authorized responsibility to observe a path of suspicion. Regrettably, many nonetheless merely word the incidence of excessive meter readings and cross on all accountability for additional investigation to remedial therapy contractors.
“These contractors have a vested business curiosity, encouraging over-specification. Ought to a mortgage firm insist on work you imagine is misguided, problem this and think about acquiring a written report from an impartial surveyor or architect.
“Efficient remedial measures depend upon correct prognosis,” says Douglas, “however making use of staged treatments will also be a part of understanding the reason for a humid downside. Earlier than deciding on extra in depth work, the primary treatment might contain nothing greater than fundamental upkeep comparable to clearing a blocked rainwater gulley.
“Cures will both remedy dampness by addressing the trigger (for instance, enhancing drainage) or will handle it by treating the signs (altering washing or cooking habits, for example).
“Be sceptical of written ensures, which are sometimes loaded with get-out clauses and should haven’t any insurance coverage backing. The appropriate strategy out of your contractor coupled with good workmanship is your finest assure.”