How Much Does Humidity Treatment Cost in 2026?
The price of humidity treatment varies greatly depending on the technique used, the surface area involved, and the accessibility of the site: resin injection against rising damp generally costs between 80 and 150 €/lm, full peripheral drainage between 150 and 300 €/lm, and basement tanking between 80 and 200 €/m².
This guide details the price ranges by technique, the factors that cause them to vary, and points of vigilance for comparing quotes reliably. The amounts are indicative and commonly observed on the French market in 2026; they must be confirmed by a personalized diagnosis.
Factors That Influence the Price
Surface and linear meters to be treated. The total price depends directly on the wall measurement or the basement surface area concerned, but also on the height to be treated (rising damp that has migrated high requires more material).
Wall thickness. A 60 cm stone wall consumes more resin and drilling time than a 20 cm concrete block wall.
Site accessibility. A clear exterior wall is treated faster than a cluttered interior wall, or a basement accessible only by a narrow staircase.
Region and local labor. Rates vary significantly between Île-de-France, large regional metropolises, and rural areas.
Material and technique. Type of resin (silicone, siloxane, acrylic), tanking system (hydrophobic mortar alone, resin, membrane), or type of drain directly influence material costs.
Condition of the substrate. A heavily degraded wall requiring extensive stripping increases the duration and cost of the project.
Average Price per Technique (2026 Ranges)
| Technique | Unit | Low | Average | High |
|---|---|---|---|---|
| Resin injection (rising damp) | €/lm | 80 € | 110 € | 150 € |
| Basement tanking (waterproof mortar) | €/m² | 80 € | 130 € | 200 € |
| Peripheral drainage | €/lm | 150 € | 220 € | 300 € |
| Saltpetre treatment (neutralizer + coating) | €/m² | 40 € | 60 € | 90 € |
| Expansive resin injection in crack | €/lm of crack | 50 € | 90 € | 140 € |
| Single-flow VMC (installation included) | House package | 800 € | 1,500 € | 2,500 € |
| Double-flow VMC (installation included) | House package | 3,000 € | 5,000 € | 8,000 € |
| VMI (Ventilation by Positive Input) | House package | 1,500 € | 2,500 € | 4,000 € |
| Full professional diagnosis | Package | 150 € | 300 € | 500 € |
These amounts concern the treatment itself; finishes (final coating, painting, flooring) are generally billed separately, once the wall drying period is complete.
Price by Property Type
Old single-story house with rising damp. The linear meters to be treated correspond to the exterior perimeter and the affected load-bearing walls, i.e., 30 to 60 lm for a standard house, with a global budget often between 3,000 and 8,000 € for resin injection alone.
Ground floor apartment with localized rising damp. The linear meters involved are more limited (exterior walls), budget lower than that of a complete house.
Basement or cellar with complete tanking. A medium-sized basement (30 to 50 m² combined walls + floor) often represents a budget of 3,000 to 8,000 € for complete tanking, to which additional peripheral drainage may be added.
Basement with conversion project into a living room. The budget then integrates the treatment (tanking, drainage, ventilation) and the actual renovation work.
What is Included or Not in a Quote
A rigorous quote must explicitly specify:
- The preliminary diagnosis (included or billed separately)
- The exact technique and product used
- The precise surface area or linear meters treated
- Preparatory work (stripping, crack treatment)
- The proposed warranty and its duration
- What is not included: finishes, rubble removal, potential additional ventilation treatment
A quote that does not clearly specify these elements, or offers an "all-inclusive package" without detailing quantities, is a warning signal to take seriously before signing.
Available Grants and Subsidies
Humidity treatment generally does not fall within the scope of the main energy renovation grants (which target thermal insulation and heating), with the exception of certain ventilation components eligible for a reduced VAT rate for renovation work in homes over two years old. Conditions evolve regularly: it is recommended to check the applicable scheme at the precise time of the project with official bodies, rather than relying on non-updated information.
How to Get a Reliable Quote
- Always request a diagnosis before a quote, with an objective measurement (hygrometer, calcium carbide test) rather than a simple visual estimation.
- Compare at least three quotes detailing the same technique, for the same surface area, with the same level of preparation.
- Check the proposed warranty and its real duration: a significant price gap is sometimes explained by a difference in warranty or product quality.
- Ask for verifiable references for projects several years old, to judge the real durability of the treatment.
Why to Beware of Abnormally Low Prices
A quote significantly lower than the ranges above deserves careful examination: drilling spacing too wide (partially ineffective treatment), lower quality product, very limited warranty, or an absence of serious preliminary diagnosis. In humidity treatment, the cost of poorly performed work—restarting the project, untreated damage getting worse—generally far exceeds the initial savings.
FAQ
Is humidity treatment tax deductible?
It depends on the property status (primary residence, rental property) and the exact nature of the work; for a rental property, these works can in some cases be considered deductible charges from rental income. It is recommended to check this point with a tax professional according to the specific situation.
What is the average price per m² to treat an entire house?
There is no universal price per habitable m², as the treatment focuses on the linear meter of wall or the specific wall surface area concerned, not the total living space. This is why a precise diagnosis is essential before any costing.
Why can quotes for the same job vary from single to double?
Differences are generally explained by the chosen technique, product quality, hole spacing, or the actual surface area treated, and the proposed warranty duration. Comparing detailed line-by-line quotes, not just the total amount, is essential.
Does the price include repainting after the work?
Rarely: finishes are generally billed separately and must anyway wait until the wall drying period is complete (several months to over a year after a resin injection).
Do I have to pay for the diagnosis even if I don't hire the same company for the work?
It depends on the company: some offer a free diagnosis without commitment, others bill for a detailed diagnosis with a written report, deductible if the works are then entrusted to the same company. This point should be clarified before the visit.
ZeroHumi offers a free diagnosis and a detailed line-by-line quote, to calmly compare solutions adapted to your home. Request a quote →
Sources et références
Cet article s'appuie sur des sources officielles et vérifiées pour garantir la fiabilité des informations.
- [1]
- [2]Reduced VAT rate for works— Ministry of Economy
- [3]
Rédaction ZeroHumi
Équipe éditoriale ZeroHumi
Documentation technique vérifiée à partir des sources citées (ADEME, ANSES, OMS, CSTB, CEREMA)