Damp, mould, stains and flaky plaster in basements are a homeowner’s worst nightmare. We’ve mentioned numerous times that weather events and groundwater, where not controlled properly, are the main cause of damp. Of course, it doesn’t just affect the walls, but the whole structure, including flooring, on the basement level or even on the ground floor.
The phenomenon that’s so often underestimated is so-called “rising damp”, which occurs when water under the ground enters walls as a result of direct contact and is pushed upwards by capillary action, allowing the moisture to rise around ten centimetres or more. The moisture can even climb metres up the wall by “latching on” to molecules of a different kind, in this case those of the actual walls. The damage caused by the abnormal increase in moisture inside walls is immediately visible on the walls of ground-floor rooms or basements.
What effects the water’s capillary action has
The effect of capillary absorption manifests in the form of:
- static damage to the building, which is weakened and becomes less safe
- worsening occupant comfort as a result of unhealthy, smelly rooms
- cosmetic damage, with the appearance of stains and peeling plaster
- higher heating costs due to the lower surface temperatures of internal walls
- a capillary action that causes water to rise through walls, bringing with it salts from the ground that, once they crystallize as a result of the evaporation process, swell and cause paint and plaster to peel: white stains forming around cracks are known as salt efflorescence.
The effects are less visible when the surface affected is flooring, with symptoms like swelling, salt efflorescence, mould or changes in the colour of grout often only appearing later on.
All these issues derive from the misguided choice of materials, or poorly designed and executed work, often compounded by the fact that the foundations’ waterproofing is damaged or even non-existent. This is not an issue linked to weather events, rather it stems from the presence of groundwater.
How TeMa Building Solutions can help
Both rising damp and efflorescence issues can be prevented with the use of suitable materials. TeMa Building Solutions offers an extensive range of studded membranes and drainage geocomposites to remove water before it comes into contact with the structure and to provide waterproofing with reliable, lasting protection.
Our engineers are here to help you choose the right specific product for your next project.
TeMa Geo Solutions’ thirty years of experience extends to the field of controlled landfills and contaminated sites, with products specially designed for each function to ensure the site is safe, and with investment-conscious solutions, as well as a focus on ensuring peak performance.
Safe landfills legislation
In Italy, regulation around the controlled disposal of waste dates back as far as 1982, later supplemented by the European directive and updated in 2020 by Italian legislation (D.Lgs no.121).
This legislation covers all aspects of the disposal cycle, from landfill classification to the type of waste, as well as criteria for the construction and operation of the facilities, with a strong environmental focus. In this regard, TeMa has come up with built-up systems and materials that fulfil the required functions and comply with the relevant legislation.
The main functions to make safe a controlled landfill
Making safe a landfill facility entails fulfilling a number of functions:
Walls and floor must be isolated to protect groundwater and soil from leachate and biogases resulting from decomposition processes. To ensure sufficient watertightness, legislation requires the use of at least 0.5 m of clay or, drawing on the principle of hydraulic equivalence, synthetic products: sodium bentonite composites like Barrier Bento — which contains up to 5 kg of bentonite/sqm sandwiched between two geotextiles — provide an impermeable layer, acting as a barrier between soil and waste.
One of the major issues to be addressed when designing landfills, especially the capping system, is stability, which can be achieved by leveraging the compressive strength of the soil combined with the tensile strength of geosynthetics. Reinforcement solutions provided by TeMa range from PET-series geogrids to geomats laminated with geogrids.
For liquid and gas capture, legislation calls for the use of 50 cm of aggregate, which nonetheless can come with its own stability issues, especially on steeper slopes. With the use of drainage geocomposites, the relevant built-up system can be pared back, while the number of vehicles required to carry materials can also be reduced. TeMa’s offering ranges from studded and micro-studded membranes to monofilaments laminated with nonwovens, and geonets with one or two nonwoven layers.
The top layer of the soil is eroded by the action of the elements — especially by the type of unpredictable and extremely violent weather events we’ve witnessed in recent years — triggering alarming landslips, which can undermine a site’s hydrogeology. To prevent issues of this kind, it’s essential to encourage vegetation (which serves as a form of natural erosion control) and protect the soil while it takes root by using natural or synthetic mats from TeMa.
Something of an innovation in the Italian building scene, while also being a useful device for protecting the roof, the ballasted flat roof is a solution that can become a distinctive feature of either a residential or commercial building.
Unlike the traditional system involving the use of concrete, using gravel is an option that brings a number of attractive advantages:
- it protects the roof against wind and UV rays
- it protects the roof against mechanical damage
- it is low maintenance
- it provides thermal comfort in summer as it shades the roof
- it makes the whole roof system practically fireproof
- it is long lasting.
In building, the choice of a ballasted roof is often prompted by aesthetic reasons for a holiday home or a hotel by the sea, or in an area with high sunshine hours… while it also caters to the need for optimal insulation and low maintenance.
The TeMa Building Solutions answer for protecting ballasted roofs
When gravel is laid, the load can tear the waterproofing layer on the roof underneath, and this comes with the risk of leaks, with all the ensuing stain, mould and structural damage issues.
So it is important to address the need for rainwater drainage and mechanical protection of the waterproofing.
TeMa Building Solutions has come up with a product that serves multiple functions: the product in question is T-Kone G Drain, the studded membrane (which serves to protect the waterproofing) featuring a geotextile (addressing the need for filtration and separation).
Placed between the gravel layer and waterproofing, T-Kone G-Drain is thin, strong and ideal for an effective build-up without the bulk.
With the new EPD certification, TeMa Technologies and Materials provides information about the level of sustainability of its products: this includes most of the membranes and geocomposites manufactured on its production lines. For 30 years, TeMa has regarded environmental protection as a duty and obligation towards the community and future generations.
What is EPD and what is analysed to obtain it?
The Environmental Product Declaration (EPD) is a document that provides specific data on the life cycle of products or a service. It measures the impacts that the production and life phases of a product have on the environment by means of a Life Cycle Assessment to determine the consumption of resources such as water, materials and energy.
It is voluntary and verified by the independent third party SGS so that certified declarations can be given to clients.
The EPD document is internationally acknowledged, as it complies with ISO standards. This ensures use, credibility and stability over time, making the data collected available for use in any type of environmental management system and providing information for environmental certification protocols for buildings and infrastructures.
Which product lines from TeMa Building Solutions are EPD certified?
The products having obtained EPD certification are:
- the studded membrane line, which includes Membrana Nera, Membrana Nera Geo, T-Kone, Tefond, HDD, TM and MD;
- the monofilament drainage line comprising Q-Drain C and Q-Drain ZW;
- the anti-erosion and reinforcement geomat line, which includes K-Mat and X-Grid AM.
Our certificates can always be consulted by clicking here and entering TeMa in the filters.
Many factors can influence the presence of damp stains on the walls of your home. It isn’t pleasant to find that your walls are damaged low down and you need to do something about it. However, there are ways to prevent the problem directly.
Let’s take a closer look at the causes of damp walls and the best way to deal with it.
What causes damp in interior walls?
The main causes are:
- A burst pipe: as damaging as it is unpredictable, it leads to water leakage that very quickly makes the consequences apparent.
- The absence of waterproofing: walls in contact with the ground are exposed to rising damp from the ground. During the construction stage, it’s therefore necessary to waterproof the building, giving special attention to ground floors and basements, especially in the case of country cottages and villas.
- Damage to the waterproofing layer: as previously mentioned, it’s good to waterproof, but it’s also necessary to apply a protective layer that can withstand heavy loads and hydrostatic thrust from the ground. Only then will the waterproofing last intact.
- Inadequate ventilation of rooms: air saturated with moisture creates no less damage than the factors described above. If a wall is cold and the interior of a room is warm, water vapour turns to condensation. It is therefore advisable to provide adequate ventilation of rooms.
What are the consequences?
First of all, there is efflorescence, i.e. the solidification of salts in water, which appears as white spots. This is followed by swelling and flaking of the plaster.
Lastly, mould stains may appear.
This affects the aesthetic appeal of rooms, but even more so their liveability: unhealthy and potentially harmful mould and damp can cause much damage to human health if not quickly removed.
What NOT to do?
Unfortunately, mould and damp appear and we can try to contain (cover) the damage.
It’s a good idea to consult a specialist to find out the extent of the problem and possibly find a tailor-made solution.
But it’s certainly not a solution to try and cover up the damage, like sweeping the dust under the carpet: the problem remains. What’s more, there’s the risk of it recurring and getting worse because insulating paints and tiles prevent it from drying out.
How to prevent it: recommendations from TeMa Building Solutions
Prevention is always the best approach in this case: by providing appropriate waterproofing, drainage solutions and mechanical protection of the waterproofing from the outset, you can avoid the costs and difficulties that would arise once the damage has been done.
TeMa Building Solutions therefore recommends itsT-Kone Plaster studded membrane and its accessories.
The studs create an air gap of 8 mm that ensures constant air circulation and, thanks to the profile at the base, eliminates excess moisture. It needs to be applied with the nails provided after cleaning and levelling the surface, thereby providing perfect adhesion for plaster.
Go to the specific page to learn more.
“A hole in the roof is enough to ruin a home.”
So the (Italian) saying goes. Of course, there may not be any holes in the roof in the strict sense of the word, but, unfortunately, in a broad sense there might be. Roofs are subject to problems such as water seepage, damp and, in the case of trafficable flat roofs or car park roofs, heavy loads.
The roof is the part of a building directly exposed to weather conditions, such as rain, snow and hail, but also to heavy loads. It’s the least visible part of the house and the most difficult to inspect. When building a roof, it’s therefore essential to consider factors that might affect its integrity and safety, as well as harm the health of occupants.
Water seepage leads to damp and peeling walls. Dampness means mould and unhealthy attic environments.
So, let’s take a look at the main problems and see what solutions can be found.
Ponding on a roof will wet and ruin the materials used. It’s therefore necessary to install a drainage system for rainwater or, in the case of trafficable flat roofs, for accidental leaks of oil or fuel from vehicles. This applies to green roofs, trafficable flat roofs and ballasted flat roofs.
Solutions need to be found that don’t increase the “load” on the roof.
TeMa Building Solutions recommends installing its drainage geocomposite , T-Mix Drain Plus and TMD 1011, ideal for trafficable flat roofs and flat green roofs; its T-Kone G Drain studded membrane, suitable for ballasted flat roofs and flat green roofs; or T-Net Drain geonet for trafficable flat roofs.
It’s also necessary to focus on vapour control. Due to temperature differences between the air and the roof material, there’s a risk of condensation forming. To prevent this, highly waterproof vapour diffusion membranes need to be laid.
The membranes in the T-Vapo range act as a barrier, retarder and vapour diffuser for pitched roofs.
Mechanical protection of waterproofing
The first step is to ensure that the waterproofing layer is intact and remains that way. Any cracks, cuts or inaccurate application in corners can cause irreparable damage to the underlying surface, requiring major intervention and considerable costs. By the time damp patches appear, the damage is often already severe.
Moreover, in the case of roofs used as parking areas or flat green roofs, the heavy weight that the materials need to withstand must be considered.
TeMa Building Solutions proposes its T-Kone G Drain studded membrane and the Tematex range of geotextiles for flat green roofs.
Research conducted in the building market has found that most construction disputes are due to damage caused by water and damp seeping into retaining structures.
In order to avoid inconveniences of this magnitude that are discovered in the course of time, designers and installers undertake to protect foundations. TeMa has therefore developed products and systems that protect waterproofing during backfilling operations, thus guaranteeing the stability of intervention work over time. For practical purposes, we propose two types of fairly common intervention works in civil engineering by showing you how two of our studded membranes work.
Retaining walls are intervention works that have the main purpose of retaining slopes or soil embankments during works such as the construction of roads below ground level. Various types of wall can be built: in masonry or reinforced concrete, or using precast concrete elements.
Whichever solution is used, you always need to consider and comply with specific hydrogeological features: TeMa laboratories offer a range of membranes that meet such requirements, whereas technicians and installers can assist in choosing the best solution to use.
Mechanical protection of waterproofing
For the mechanical protection of waterproofing you can choose T-Kone, which also performs a damp-proofing and drainage function. Damp proofing creates a physical barrier between the structure and damp soil and avoids any possible damage to the waterproofing membrane, both during onsite operations and soil settlement.
The T-Kone family is part of a range of bare HDPE studded membranes (such as T-Kone S). Alternatively, these membranes can be bonded with a geotextile such as T-Kone G Drain or with a geotextile and a damp-proofing element such as T-Kone G Drain Plus.
Diaphragms and berlin walls
Suppose we need to work in an urban context doing underground intervention work. First of all, we must guarantee the stability of the structures surrounding the area to be excavated.
Diaphragms and berlin walls are used in situations where it is impossible to create excavation walls with an appropriate slope to prevent landslides or structural subsidence. In the form of steel/ reinforced concrete piles or walls, they are driven deep into the ground and coupled with TeMa membranes, which provide damp-proofing, mechanical protection or drainage functions.
Damp-proofing, mechanical protection or drainage functions
For this purpose, products such as Q-Drain can be used, which have a polypropylene monofilament drainage core bonded with one or two non-woven geotextiles, also made of polypropylene. These filter water and adapt to the conformation of the ground, thus guaranteeing stability.
These are just some of the membranes we are able to supply. Find out which one is best for you and assess the best solution with our team of experts. TeMa will assist you throughout each phase of the design process.
To discover TeMa products, visit the website.
The appearance of damp on walls may be due to various possible causes. The most common include the absence of waterproofing systems in the external part of the wall, the one in contact with the foundation soil, the absence of any efficient mechanical protection that may cause damage to the waterproofing system, or the presence of air saturated with moisture – due to inadequate ventilation – that comes into contact with cold masonry and is, therefore, not thermally insulated.
All this may cause a series of phenomena such as the appearance of whitish areas on walls. These are more frequently known as “efflorescence” and are caused by the build-up of salts, which may lead to the detachment of the surface plaster.
However, walls cannot always be restored from the outside. To solve this problem of an unhealthy environment, TeMa Building recommends T-Kone Plaster, a studded membrane that acts as a cavity.
T-Kone Plaster acts from the inside of a house by creating an 8 mm air gap, equal to 5.4 litres/m², between the original wall and the new finish. Thanks to its mesh, this can be coated with a new layer of plaster while its special profile at the base is able to counteract moisture through micro-ventilation.
Rot-proof, non-toxic, resistant to atmospheric agents and fungi, T-Kone Plaster is an effective and permanent solution for restoring walls.
To find out more about our studded membrane, EXPLORE OUR WEBSITE.