WHY SEAL MASONRY AND CONCRETE?
There are many causes and indications of moisture damage and we often informed of situations that are not based on fact. Worse still, there are a lot of products that claim to solve moisture problems, that are not backed by knowledge or experience. Occasionally we hear about «experts» who measure moisture in concrete with equipment meant for wood, «experts» who cannot distinguish between condensation and moisture penetration…some who believe that coating with paint or membranes is the solution.
Moisture damage can be expensive in many ways, and it is therefore essential that the correct know-how and expertise is used as the basis for prevention and improvement.
There is often much confusion even among the trade press and media who generally express themselves incorrectly…confusing cement for concrete, for example, cement walls, cement mixers, cement floors etc. instead of concrete walls, concrete mixers, concrete floors.
Efflorescence (salt or limescale) is often wrongly referred to as «clear» signs of fungi and mildew.
In this section we will create a better understanding of moisture problems in brick and concrete construction.
WHAT EXACTLY IS CONCRETE?
Ordinary concrete (also applies to finished concrete products) is a mixture of five components: sand, gravel, cement, water and air. Water and air take up as much as one-fifth of the space in the concrete, leaving behind pores, pockets and veins after curing.
These cavities are linked, and together they constitute an efficient water transport system (capillaries). Water carries pollution, acid rain, salts and depletes the strength and density of the concrete.
Using Controll®Innerseal, these cavities are sealed when the product crystallises inside the concrete’s capillary system to prevent moisture penetration. Using our products properties such as colour, texture, appearance or other things will not be affected…application will leave a clear and natural surface, without a membrane or film.
- SINGEL / TILSLAG 41%
- SAND 26%
- VANN 16%
- SEMENT 11%
- LUFT 6%
WHAT EXACTLY IS CONCRETE?
Controll® Innerseal is a silicate-based concrete sealant that was originally developed and specialised for industrial use to overcome concrete damage caused by moisture and chemicals penetration. It was necessary to find a product with high performance in terms of cost/benefit, simply because of the high demand. Using advanced silicates (waterglass), an exact chemical formula and the process was developed by our experts in the field with many variants tested extensively before the final result was perfected.
Our production methods and advanced filter technology have become much more advanced and today the particle size of the silicates has been reduced to an average of 0.7 nanometres with 20% being between 0.1-0.4 nanometres.
This process and unique filtration system enables Controll® Innerseal to penetrate deeply into microcracks, capillaries and the pore system. It bonds with different minerals (mainly salt and lime) to form insoluble and dense crystal formations that prevent moisture migration and resulting damage.
Controll® Innerseal is also permeable and allows the release of moisture in the form of vapour. This is because water in vapour form has a much smaller molecular size than liquid water, allowing it to evaporate through the crystal grid. While the concrete is allowed to breathe, the product will prevent the absorption of water, oils, acids and other degradants. Although permeability is vital to maintaining the overall quality of the concrete, this feature is unfortunately not characteristic of many other sealing products on sale.
WATER AND MOISTURE INFILTRATION
The infiltration of water into the pore and capillary system is the principal factor in concrete deterioration.
Water introduces degrading agents such as pollutants like salts and acids into the concrete and leaches valuable elements such as lime from the concrete and is also a cause of frost-cracking and rebar corrosion. Sealing with Innerseal blocks the concrete’s pore and capillary system and prevents water from passing through thus preventing moisture in masonry and concrete in a simple way.
Frost damage is caused by the expansion of freezing water in pores and pockets in the concrete.
When water freezes, it expands by approximately 9%, and the forces generated are stronger than the concrete can handle. These forces further increase when the concrete thaws, and then freezes again and again. In wintry conditions when salt is applied as a de-icer on concrete, the volume required by refreezing is doubled. The result is even more flaking, more cracking and crumbling.
Because Controll® Innerseal tightly blocks the pores and pockets in the concrete, water infiltration is prevented.
Robust concrete must have a pH value between 11 and 13. If the pH value of concrete is below 9 as a result of continuous water contact, the main cause of rebar-rusting is present.
Controll® Innerseal has a pH value of 11.3 and therefore prevents concrete deterioration.
When rebar rusts, it can expand to a volume up to 9 times greater than its original size, and considerable forces develop in relation to the tensile strength of the concrete. In early phases, fissures and cracks are formed, usually visible as rust-water staining on the surface. Eventually this will lead to weakened rebar cross-sections, and the consequence is reduced load-bearing capacity for the structure.
Sealing with Controll® Innerseal completely seals and isolates the rebar from water contact.
ACID RAIN AND CARBONATION
Airborne pollution is one of the principal causes of concrete degradation.
Sulphur dioxide (SO2) and carbon dioxide (CO2) in the air is absorbed in rainwater to form acid. The acid rain enters the concrete and forms calcium sulphate, which first becomes a thin membrane on the concrete surface. Under this membrane, more calcium sulphate forms which dissolves the concrete and causes crumbling, flaking and rebar rust.
Controll®Innerseal seals permanently to prevent moisture absorption. In preventing rebar-rust, Controll®Innerseal also increases the pH value, preventing deterioration of all concrete.
Air contains moisture in the form of water vapour and the more it cools the less moisture it can hold. When humid air meets a cold surface it releases water, which is called condensation…a good example being warm «summer air» settling on basement floors or foundation walls. Over time, condensation will damage insulation, rot wood and create a musty basement smell. This also causes fungal and mildew growth which in turn can cause respiratory allergies.
Condensation can be temporarily controlled by installing a dehumidifier but only for a short period of time to dry out the structure. Adequate natural or mechanical ventilation should then be permanently installed. This is especially important for cold ceilings and walls where invisible concrete damage can build up and eventually cause failure in load-bearing structures.
Using a dehumidifier to solve the problem of moisture resulting from groundwater whether it is through floors, walls or ceilings, will work temporarily but in actual fact increases the seepage of water and accelerates leaching…when the dehumidifier stops the moisture returns.
Use of Controll Innerseal prevents moisture from accumulating in concrete.
IS RETROSPECTIVE PREVENTION WORTH IT??
Car-park decks and garage floors must be capable of withstanding heavy loads, studded tyres, road salt, exhaust and deposits from chemicals like antifreeze, engine oil, brake fluid etc. These floors must also be capable of withstanding temperature fluctuations with annual differences of over 60 degrees in some cases.
Property owners often are ignorant of the fact that concrete constructions are susceptible to the affects of weather and pollution and subsequently require ongoing care and maintenance. The long-term life of concrete is dependent on having sufficient protection to prevent water penetration.
Without water, salts and other pollutants cannot be transported into the concrete structure and carbonisation cannot occur.
There are many waterproofing products on the market such as water-repellent sealants, special mortars, membranes and epoxy coatings. Common to them all is that they only add one or more temporary extra layers on the surface of that we wish to protect. The concrete itself will not be sealed, it will still absorb and transport water when the outer layer fails. It is therefore essential that all outer sealant products are applied under very strict and accurate conditions.
Using Controll Innerseal eliminates these problems.
The concrete itself will not be sealed, it will still absorb and transport water if the outer layer fails. Therefore, it is very important that all outer sealant coatings are applied under very strict requirements and with great accuracy. The problem is, however, that the external high quality layer is so thick that the concrete cannot be visually inspected. Damage can thus develop into a disaster area before it is discovered, and the bill will be sky-high. However, there is a solution. Controll® Betongtett is a well-proven deep sealant highly suitable for preventive protection under such coatings. It is designed to seep into the concrete, when the polysilicates will crystallise in the pore and capillary system. This blocks the concrete’s ability to absorb and transport water, thus preventing the permeation of such substances as salt water. The active substances are thus integrated as a permanent physical component of the concrete itself and cannot be washed out, worn down or flake off.