Damp, rising damp and efflorescence in basements.
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
- efflorescence
- 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.
Contact us!
- Published in BUILDING, Drainage geocomposites, Foundation and underground structures, Foundation and underground structures - Damp proofing systems, Foundation and underground structures - Drainage systems, Foundation and underground structures - Systems for mechanical protection, Foundation and underground structures - Systems for Waterproofing
Solutions for protecting foundations and below-grade walls
The health of walls in contact with the soil — like foundations and below-grade walls — is the primary concern of the home’s occupants, especially where underground garages or basements are involved: any sign of damp or mould is evidence of damage that can have serious financial consequences in these areas of the building. And restoring the interior to good health is not always feasible.
The risks lie both in the foundations — namely in the horizontal structures that receive and absorb the loads of the whole building — and in the below-grade walls, namely the vertical structures that have to withstand considerable loads. If we take the worsening weather patterns of recent years and add in pesky capillary rising damp, and groundwater pressure, there’s clearly a need to ensure the products used provide improved performance.
How do we best protect foundations and below-grade walls?
The way to keep underground rooms healthy is to use specific, tried-and-tested products, applied correctly as per the technical literature. TeMa Building Solutions has various solutions on offer.
Bentonite geocomposites
Bentonite geocomposites can be used to ensure the concrete is properly waterproofed. Comprising natural sodium bentonite, they self-bond to concrete (if used as waterproofing prior to insitu casting) and are suitable for both vertical applications (below-grade walls) and horizontal applications (slab foundations).
Studded membranes
Studded membranes are one of the most widely used products given their dual function:
- they mechanically protect waterproofing: they prevent damage to the waterproofing layer during the backfilling and compaction process at the construction phase, and protect from the subsequent micro-movements as the soil settles, and the considerable loads that the walls have to withstand
- they serve as damp-proofing: they stop moisture, which — even in the absence of hydrostatic pressure — can undermine the structure and cause patches of mould to appear on internal walls.
Drainage geocomposites
They reduce hydrostatic pressure exerted on vertical walls, conveying water away from the walls to the outer perimeter. They are laminated with one or two nonwovens serving as a filter layer, stopping the system becoming clogged. The TeMa Building Solutions range includes geonets, studded membranes and monofilament structure.
Need help choosing the right product? Contact us! Our experts are here to help you any way they can.
Waterproofing when concrete casting
Concrete casting involves creating a new concrete element as a continuation of an already existing one. Most often it’s impossible to create a monolithic block with a single casting: consider, for example, very large structures or the connection between vertical and horizontal walls. With concrete casting you can obtain monolithic structures with their own characteristics, built in stages at subsequent times. So, you proceed with small blocks and join each casting to the previous one, creating a monolith piece by piece.
Structural connection is achieved by using reinforcing irons, taking special care with drilling the existing block and the length of anchorage. While ensuring attachment to the sequence of blocks, reinforcing irons are potential lines for water seepage. We well know that accumulation of moisture in walls may have very severe consequences: structural fragility and very unhealthy stains and moulds.
An effective solution is to insert bentonite kerbs which waterproof any voids that may have formed at the base of walls or in contact with reinforcing irons. The intrinsic property of sodium bentonite is exploited, which is the ability to swell on contact with water, filling the available space and forming an impermeable compound.
Furthermore, this material provides high resistance to hydraulic load, is easily applied and adheres perfectly to the support.
The range of building products from TeMa Building Solutions also includes T-Bentostop, the waterstop made of hydro-expanding bentonite for waterproofing and sealing concrete casting.
Can’t go up? Let’s make space below!
Nowadays, certain solutions allow you to create perfectly liveable and comfortable basements.
Of course, existing little-used basements can also be renovated, but you need to take some constructive measures to ensure that the building is in good condition and the environment is healthy.
So let’s see what we need to focus on.
Damp and moisture seepage
Basements are in direct contact with the ground, both the floor and the vertical walls.
Rainwater or ground moisture can penetrate concrete, leading to marks and mould that may cause the wall to peel. The aesthetic damage is as serious as the structural damage: mould is anything but healthy!
It therefore becomes necessary to provide a separation barrier between the structure and the ground that performs the function of damp-proofing, i.e. controlling moisture in the absence of hydrostatic pressure (click here to read more).
TeMa Building Solutions suggests T-Bentostop, in the F and F XL versions, a geocomposite, which attaches to concrete and consists of natural sodium bentonite with a waterproofing function, and T-Kone, the HDPE studded membrane available in several versions.
Drainage
Groundwater or dispersed water may flow in the ground, even near structures, therefore increasing the load on walls. So, it is essential to drain water and prevent it from entering by reducing the hydrostatic pressure on surfaces: T-Kone G Drain, T-Net Drain studded membranes and the drainage geocomposites in the T-Mix Drain range perform this function while keeping walls dry.
Mechanical protection of waterproofing
The vertical walls of basement rooms have to withstand heavy loads exerted by the ground. It is therefore essential to provide systems to protect the waterproof layer in order to guarantee the safety and long life of the building.
The T-Kone, T-Kone Star and TMD (also in the Plus version) range are studded membranes specifically designed for foundations and underground structures: their high load-bearing capacity makes them ideal for such applications.
Aeration
To keep masonry dry and allow constant and substantial air circulation, studded membranes can be installed with the studs facing inwards. In this way, their raised shape creates aeration channels that allow the wall to literally “breathe”.
Ideas for renovating your basement
It has been estimated that the value of your property increases by about a third if you have a well-planned basement. An extra room is always very useful and its intended use may vary greatly.
You can opt for a studio for working from home, a spacious laundry room for hanging up your washing, a playroom for your children, a relaxation area, a rehearsal room for talented home musicians, or even a free space for hosting friends, a wine cellar for preserving the best bottles with a tasting area, a gym or a personal home cinema.
- Published in BUILDING, Drainage geocomposites, Foundation and underground structures, Foundation and underground structures - Damp proofing systems, Foundation and underground structures - Drainage systems, Foundation and underground structures - Systems for mechanical protection, Foundation and underground structures - Systems for Waterproofing, Studded membranes and accessories
Damp Proofing vs Waterproofing
Damp-proofing and waterproofing are terms we often encounter in the building industry and they refer to a specific function. In product presentation and technical documentation, the two terms are often equated, leading to confusion, also due to “cross-translations” from English into other languages.
Important differences distinguish these two terms. Whether you are planning a new construction or a renovation, it is better to know the meanings in order to ensure optimal construction that also allows, when envisaged, comfortable living on basement floors.
In this article, we can try to better understand the difference between the two terms.
What does “damp-proofing” mean?
Damp-proofing is the function of a material that can slow down or prevent, on a surface, the absorption of moisture (i.e. in the absence of hydrostatic pressure). The main purpose is therefore to slow down moisture seepage, but it does not prevent the flow of water to the interior.
These materials also often have the additional important function of creating a barrier between the ground and the surfaces to protect the waterproofing layer, increasing its safety and durability over the years.
What does “waterproofing” mean?
Waterproofing means the ability of the system to be totally resistant to water in the ground, which exerts hydrostatic pressure. Such as groundwater, for example.
TeMa Building Solutions always guarantees a range of products and has all the solutions you need.
For the damp-proofing function we have T-Kone, the HDPE studded membrane for foundations and underground structures, and its accessories including washers and nails for installation (T-Plug + Nails), whereas for the waterproofing function we have T-Bentostop F and T-Bentostop F XL: waterproofing bentonite geocomposites that self-attach to concrete for foundations in that material.
Contact us for further information or visit our product pages specifically for damp-proofing and waterproofing functions.
The importance of guaranteeing protected foundations
Cloudbursts are sudden heavy rainstorms that, unfortunately, are becoming increasingly frequent. Short but intense, they mainly occur in the summer season, even if it is a myth to debunk because they are also a common occurrence in other seasons. The enormous amount of water concentrated over a short period of time, makes these phenomena potentially dangerous and a possible threat to the foundations of buildings.
How to Protect Foundations
This is why designers are increasingly focusing on the best protection for buildings and properties in contact with the ground. The sudden changes in the amount of water run-off and the gradual increase in the groundwater level make earth-retaining works fragile when these factors have not been considered.
TeMa Building Solutions
Adequate systemic design is essential in the case of hydrostatic thrust, just as it becomes fundamental to monitor various factors, including: descending water resulting from precipitation, water and/or damp rising due to capillary upward flow, groundwater and condensation which, due to the difference in temperature between the ground and interior spaces, forms on the walls of rooms close to the ground. It’s also important to bear in mind the likelihood that several phenomena may exist at the same time. TeMa Building Solutions is our division highly specialised in protection and waterproofing systems. Our research team has developed products ideal for counteracting the hazards caused by these seasonal weather events. It provides solutions for the protection of foundations and water drainage to reduce the volume of water close to underground structures, both vertical and horizontal, in contact with the ground and where groundwater or dispersed water is present.
TeMa Geocomposites
Our geocomposites have been designed to perform the dual function of filtering and draining water, dispersing energy from the hydrostatic load. They include T-Net Drain 5, which channels the flow of water to the water collection system around a building thanks to the rhomboidal-shaped mesh geo-grid coupled with two non-woven geotextiles.
According to recent research in the building market in Italy, damage due to water seepage and damp in earth-retaining structures is the cause of more than 50% of disputes in the building sector. Our designers are well aware of this problem and therefore rely on TeMa, thus preventing such complications.
To learn more and discover the entire range of geocomposites designed by TeMa, go to our website.
The importance of studded membranes
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.
Protecting foundations
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
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.
- Published in BUILDING, Foundation and underground structures - Damp proofing systems, Foundation and underground structures - Drainage systems, Foundation and underground structures - Systems for mechanical protection, Foundation and underground structures - Systems for Waterproofing, Retaining walls, Retaining walls elements, Studded membranes and accessories
For elevators… That are tested!
Just imagine the face of those present when Elisha Otis, a smart American entrepreneur, presented the first elevator in 1853. It was enlightening! During an exhibition at Crystal Palace in New York, visitors were shown how the enclosure works, which was fitted with an automatic safety device for blocking it in the event of an emergency.
Today, however, we are used to using elevators and we often complain if they are out of order and we have to go back to the old-fashioned habit of using the stairs!
But what does building an elevator involve?
Elevator pits are structures located at a lower level than the internal standing area and must be able to withstand both static and dynamic loads. In short, they need to not only support the weight of your Saturday shopping but also take it up to the fifth floor!
Many problems may be encountered when an elevator is being installed. First of all, there is the danger of infiltration and all the consequences it may bring. Then we mustn’t underestimate the fact that, in the case of a hydraulic elevator, oil may leak from the system, which is why electric elevators are always recommended. TeMa has developed the T-Kone family: HDPE honeycomb membranes that provide mechanical protection, damp proofing and drainage. As far as drainage is concerned, the research and development centre that TeMa relies on has developed drainage geocomposites that filter, protect and drain the system.
Waterproofing? Yes, but how
It is not enough to install membranes that perform a drainage function, it is also necessary to make spaces waterproof. But how? By using bentonite geocomposites that self-bond to concrete, such as T-Bentostop F and T-Bentostop F XL. They are made of a non-woven fabric and a polypropylene fabric with a layer of natural sodium bentonite in between.
These are the essential aspects that should never be underestimated for excellent, high-performance implementation. We must always remember that a thorough preventive analysis of the dangers, along with accurate and responsible installation, are the best techniques for avoiding problems and inconveniences caused by infiltration in the future.
Find out more about damp proofing, drainage, mechanical protection and waterproofing systems of TeMa Building.
- Published in BUILDING, Drainage geocomposites, Foundation and underground structures, Foundation and underground structures - Damp proofing systems, Foundation and underground structures - Drainage systems, Foundation and underground structures - Systems for mechanical protection, Foundation and underground structures - Systems for Waterproofing
