City centres are overcrowded with vehicles and restricted areas, car parks are “stressed” and there are never enough spaces to go round. Alongside the more “standard” trafficable ceiling slab solutions — such as in the case of underground garages — it’s not too much of a stretch, where structurally feasible, to think about designing or making better use of spaces on elevated levels.
Over the holidays, car parks on the roofs of public buildings or buildings for use by the public could also provide refuge for the cars of passers-through. During the offices’ closing time, for example, these parking spaces can become a real asset, an ideal solution for making use of otherwise unused space and increasing the number of car parks for people travelling to tourist hot spots
Continual vehicular traffic and exposure to the elements — from freezing temperatures to sweltering heat — mean the construction materials used must be fit for purpose. Intensive use means it’s imperative all the proper layers are in place (build-up design) to serve the different specific functions. Let’s see what these layers are.
What do we need to be careful about when designing a rooftop car park?
This kind of roof is subjected to high loads, both static and dynamic, from vehicles of all kinds. This makes the mechanical protection of the waterproofing layer and the need for high compressive strength two key focus areas.
Drainage is another aspect to be factored into the design. Rainwater can seep into the underlying layers and damage them, so we need to ensure that water is drained off the roof properly.
We recommend applying studded membranes laminated with nonwovens or drainage geocomposites made from monofilaments or geonets.
Our drainage geocomposite T-Mix Drain Plus is a good candidate for the drainage layer. Alternatively, you can opt for the T-Net Drain 5 and T-Net Drain 7 geonets, which are sandwiched between nonwovens.
The job of mechanical protection, together with drainage, can instead be handled by the drainage geocomposite TMD 1011. The product consists of a filter geotextile laminated to a studded membrane, whose conformation delivers effective drainage even under the strain of high loads (up to 400 kPa).
On flat or sloping roofs, water and moisture arrive from outside with atmospheric precipitation. However, water seepage is just as hazardous and is created inside with vapour that may accumulate as a result of temperature changes between outdoor and indoor environments.
In building elements, the persistence of moisture and condensation can cause a structure to deteriorate. This is evident in the appearance of efflorescence (those white spots that appear as a result of the solidification of salts contained in water) and, subsequently, mould.
Multilayer vapour membranes are excellent for protecting buildings against water seepage. They can be divided into vapour diffusion, barrier and retarder.
Although often confused and considered interchangeable, they actually perform quite separate functions.Let’s take a look at them in detail.
What makes them differ?
What makes these products differ is mainly the degree of vapour breathability, its resistance capacity, measured with an Sd indicator. The lower the Sd value, the more breathable the material. The UNI 11470:2015 standard sets out application methods for breathable screens and membranes and their use on pitched roofs, on continuous or discontinuous supports or in direct contact with thermal insulation.
With Sd ≤0.1 m, diffusion membranes are impermeable to water but highly permeable to vapour that is created in a room and can escape.
On roofing, a breathable diffusion membrane is applied to the outside of a building over insulation, as it facilitates the evaporation of moisture, even residual moisture, whereas on the inside – below the insulation – a retarder or barrier should be chosen.
These membranes (2 m < Sd ≤ 20 m) completely block the passage of water but only partially block vapour, thereby controlling the passage of moisture and preventing the formation of interstitial condensation.
They are generally placed inside a structure because it slows down the passage of vapour that is conveyed, in winter, by warm air to the outside and which might deteriorate materials.
TeMa Building Solutions suggests T-VAPO SLOW NET.
Lastly, a vapour barrier is a material that is completely impermeable to both water and vapour (Sd ≥ 100 m). It is mainly, but not exclusively, used in humid environments such as swimming pools.
The position of a vapour barrier depends on the heat flow: it should be placed against insulation on the warm side.
Which one should you choose?
There is no single answer. A technician will recommend the right product after a passive thermographic analysis and precise thermal engineering design. In principle, the most important factor is to block vapour where it forms while allowing any residue to pass through so that the waterproof layer remains intact.
As mentioned above, choosing which membrane to use requires an evaluation of various aspects, including climatic conditions, the type of insulation, structural components and a technical assessment based on thermo-hygrometric measurements.
Discover the full range offered by TeMa Building Solutions here.
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.
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.
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.
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.
“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.
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.
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.