Ground reinforcement and stabilization with TeMa geogrids as part of foundation groundworks
Foundation base reinforcement for the construction of rigid reinforced concrete structures on unstable areas: a challenge for engineers across the globe. Sure enough, designers find themselves having to contend with the risk of differential foundation settlement, which can result in cracks in the structure. This means any unsound material in the area often has to be dug out and carted off site, while the layers have to be built up again using materials brought in specially, which can sometimes be expensive. The foundation bed must provide the required bearing capacity and, above all, must eliminate the risk of differential settlement.
The Katlehong job, in South Africa, was a major project for TeMa in a highly critical construction context, given that it involved building a municipal water reservoir in the shape of a 200 thousand hectolitre tank.
With the introduction of a number of geosynthetic products in place of conventional building materials, the costs came in significantly lower than initially projected and structural efficiency was improved considerably across such a large project, promising to deliver a long service life.
The TeMa solution in cases like these: laying X-Grid PET-C-0 100/100 Biax — a biaxial stabilization geogrid woven from high-strength polyester, with a protective polymer coating — over the whole bed in alternating layers with fill material between. With each new layer, the geogrid has to be placed with the appropriate orientation to ensure the structure’s foundation will provide the required overall stability and bearing capacity, thus allowing for and negating the negative effects of any differential settlement.
The use of TeMa Geo geogrids allows for space to be incorporated into the design to accommodate the underground services associated with the structure being built, while providing the designer with significant advantages, compared to the use of conventional natural materials, including ease of installation and shorter construction timeframes.
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
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.
