Building and renovation
Damp proofing
Whether this needs a licence in Ireland
No licence required
Taken from the statute below; not yet reviewed by a lawyer
Damp proofing: what the job involves
Finding why a wall is damp and fixing the cause — condensation, penetrating damp or rising damp — then repairing the plaster it has ruined. Condensation is the most common cause in Irish homes and needs ventilation, not injection.
Also asked for as: rising damp · damp walls · mould on walls · condensation · damp proof course
How the job is usually done
- Survey: where the damp is, its pattern and height, moisture readings, outside ground levels, gutters, render and ventilation.
- Agree the diagnosis in writing before any treatment.
- Fix outside causes first: gutters and downpipes, cracked render, bridged damp-proof course, ground or path levels above the floor.
- Treat as diagnosed: ventilation and extract fans for condensation, a chemical damp-proof course for proven rising damp, tanking for below-ground walls.
- Strip salt-contaminated plaster and replaster with a suitable render or breathable lime plaster on older solid walls.
- Allow drying time, then decorate.
Damp proofing: what is included
Usually included
- A diagnosis of the cause
- The treatment agreed for that cause
- Removing and replacing damaged plaster in the treated area
Usually not included — agree it separately
- Gutter, roof or render repairs by other trades, unless agreed
- Mould cleaning and redecoration of the whole room
- Replacing skirting, flooring or kitchen units removed for access
Materials and who supplies them
- Damp-proof course cream or injection, tanking slurry or membrane, as diagnosed
- Salt-resistant renovating plaster or lime plaster for older walls
- Extract fans or wall vents for condensation
How long it takes
A survey takes an hour or two; treatment a day to a week, with drying time of weeks or months before final decoration.
When to book
Survey in winter, when damp is at its worst and easiest to diagnose; outside repairs and replastering go best in drier months.
Damp proofing: the rules in Ireland
What the official sources say, checked against them on the date shown. A summary, not legal advice — follow the link to read the rule itself.
Grants
Vacant Property Refurbishment Grant
Up to €50,000 to refurbish a vacant property, or up to €70,000 where it is derelict; damp remediation can be part of the approved works.
Who qualifies: Owners of properties built before 2008 that have been vacant for at least two years, to be lived in or let; applied for through the local council before work starts.
citizensinformation.ie · Checked 9 October 2026
What damp proofing costs, and why
What jobs on Talqero came to
Not enough comparable jobs yet to publish a range here. Talqero shows a price range only once at least five comparable jobs, agreed prices or offers exist — a range from fewer would describe a handful of jobs, not the market. Post your job and compare the offers you get.
What affects the price
- What the survey finds is causing it
- Area and height of wall affected
- Replastering, and the type of plaster suitable for the wall
- Outside works such as lowering ground levels or repairing gutters and render
- Moving kitchen units, radiators or skirting for access
- VAT: building work on a home is charged at the reduced 13.5% rate by a VAT-registered builder, unless materials are more than two-thirds of the price (Revenue’s two-thirds rule)
- VAT: building work on a home is charged at the reduced rate of 13.5% by a VAT-registered business — unless the materials come to more than two-thirds of the price, when Revenue’s two-thirds rule applies the goods rate to the whole job. Ask whether a quote includes VAT.
Paperwork to ask for at the end
- A written survey with the diagnosis and moisture readings
- A guarantee for any chemical damp-proof course or tanking, saying what it covers
Safety
- Black mould affects health, especially for children and anybody with asthma; ventilate and clean it while the cause is fixed.
- Do not seal an old solid stone or brick wall with cement render or impermeable paint: it traps moisture and makes damp worse.
- Damp near sockets or the fuse board needs an electrician to check.
Damp proofing: before you hire
Questions to ask a tradesperson
- What exactly is causing my damp, and how did you test for it?
- Is the treatment right for my type of wall?
- What does your guarantee cover, and for how long?
- Is VAT included?
What you can do yourself
Clearing gutters, opening trickle vents, using extract fans and drying clothes outside or in a vented dryer often solves condensation without a contractor.
What to put in your task
- Where is the damp?
- How old is the house?
- Roughly how much wall is affected?
- Has anyone surveyed it already?
Photos that help
- The damp patch, close up and the whole wall
- The outside of the same wall, including ground level and gutters above
- Any mould, salts or bubbling plaster
Damp proofing by county
Choose your county for damp proofing close to home.
- Damp proofing in Dublin
- Damp proofing in Cork
- Damp proofing in Galway
- Damp proofing in Kildare
- Damp proofing in Limerick
- Damp proofing in Meath
- Damp proofing in Tipperary
- Damp proofing in Donegal
- Damp proofing in Wexford
- Damp proofing in Kerry
- Damp proofing in Wicklow
- Damp proofing in Mayo
- Damp proofing in Louth
- Damp proofing in Waterford
- Damp proofing in Clare
- Damp proofing in Kilkenny
- Damp proofing in Westmeath
- Damp proofing in Laois
- Damp proofing in Cavan
- Damp proofing in Offaly
- Damp proofing in Sligo
- Damp proofing in Roscommon
- Damp proofing in Monaghan
- Damp proofing in Carlow
- Damp proofing in Longford
- Damp proofing in Leitrim
Building and renovation
Need damp proofing? Describe the job.
Post it once, free. Professionals near you reply with their own price and when they could start. You choose, and pay them directly.
Questions about damp proofing
Does damp proofing need a licence in Ireland?
No licence is required for this work in Ireland (source: www.cru.ie). Ask instead for references and photographs of similar jobs.
Is it rising damp or condensation?
Condensation causes mould in corners, on window reveals and behind furniture, and gets worse in cold weather. Rising damp shows as a tide mark up to about a metre with salts, and is much rarer than often claimed. A survey with proper testing tells them apart.
Will injecting a damp-proof course fix it?
Only if the damp really is rising from the ground through a failed or missing damp-proof course. If the cause is condensation, a leaking gutter or a raised path outside, injection will not help. Insist on a written diagnosis first.
Why is my old cottage damp after it was rendered?
Old stone and brick walls need to breathe. Cement render and plastic paints trap the moisture that used to evaporate, pushing damp inside. Lime render and breathable finishes are usually the cure.