Together with the foundations, a basement is the basis of a stable building. If the basement walls are not resistant to the pressure of the groundwater, this can lead to damp basement walls, fungi and other moisture problems that can damage the rest of the building. In addition, a basement is also a useful storage space where you can store a lot of items and food. It is therefore a shame if you are not able to make optimal use of this space. Basement sealing offers the right solution for this.
What is basement sealing?
Traditional basement sealing is also called basement sealing or basement sealing in technical jargon. This is to waterproof the basement walls so that they stay dry. Here you start from a watertight basement with a clean surface and damp walls.
Causes and effects of a damp basement
Moisture problems arise because the basement is not completely watertight, usually due to a combination of a high groundwater level with a low moisture resistance of the basement floor and walls or the infiltration of water from outside. Sometimes this can have local causes, such as fine hairline cracks in the walls or the basement floor. In other cases, complete surfaces may be damaged and weakened due to a lack of maintenance.
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The basement can be affected by rain or incoming groundwater, but leaks can also cause enormous havoc, making the basement walls and floor increasingly wet and wet. In addition, condensation can occur even if there is insufficient ventilation, which means that your walls become increasingly humid and, in the long run, also offer the risk of other moisture problems such as mold.
When to choose basement sealing?
Basement waterproofing is an excellent idea for waterproofing a basement, making it suitable as a practical storage space or even a living space. Sealing cellars is only effective in the case of a 'damp' basement and therefore not when there is a lot of water in the basement. Then basement drainage is initially the better choice.
A basement can be waterproofed on both the inside and outside. Waterproofing an existing home is more often used on the inside as the outside is often no longer accessible. Exterior basement sealing is often only possible for new buildings or requires extensive demolition and excavation work. For an effective result, we recommend sealing the entire basement (all walls and entire floor).
Perform basement sealing
Reynchemie has 3 methods for effective basement sealing: 1) the normal process for basement sealing at low water pressure, 2) when there is an increased pressure on the walls and 3) if there is too high a concentration of salts.
Be sure to take enough time to identify and analyse all issues.
Preliminary works
Make sure the surface is clean and structurally healthy. Remove all loose parts such as old paint, plaster, bitumen or loose joints.
Fill large imperfections (cracks and holes) with our waterproof cementation DEC 2021.
Active water leaks can be stopped with RC Plug or, in extreme cases, be injected with RC PU injector.
1) Normal basement sealing (< 1 bar)
If you do not suffer from too high pressure (less than 1 bar), vibrations from a busy track or tram, cracking or too high a concentration of salts (less than 100 mg/liter of nitrates and 250 mg/liter of sulphates), we recommend that you carry out the basement sealing with waterproof cementation DEC 2021.
RC 221 is a water-repellent mortar for rough surfaces and is intended to ensure the watertightness of concrete and masonry inside and out. For example, for ponds, swimming pools, basement walls, retaining walls...
Step-by-step plan for basement sealing with light water pressure
1) Always place a seam at the junction between wall and floor board. Apply the primer first RC Acryplast on and then place the comb wet-on-wet with RC 221.
2) Bring RC Salsper over the entire basement, including the seam, as an adhesive layer and salt inhibitor.
3) Apply an incineration coat with RC 221 and RC Acryplast.
4) Moisturize again with RC Salsper and apply a 2e coat RC 221 with a trowel or worm pump.
5) Finish the layer as desired, with a rule and rub up/talch or prepare for a final vapour-proof finish (plaster or paint system)
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2) Increased water pressure on the walls (> 1 bar)
If there is too much negative pressure (more than 1 bar) on the walls or there are too many vibrations due to a busy track/trambedding/etc., we recommend working with a flexible sealing mortar RC MULTIFLEX 2M. The product will ensure that the walls become resistant to high water pressure again (up to 8 bar).
Step-by-step plan for basement sealing with high water pressure
1) Bring over the entire basement RC Salsper as an adhesive layer.
2) Apply a scald coat with RC Multiflex 2M and let it cure completely.
3) Always place a seam with RC Multiflex 2M mixed with quartz sand.
4) Place a first coat of RC Multiflex 2M and let it cure again.
5) Apply a second coat of RC Multiflex 2M crosswise.
6) Finally, the walls can be finished with a vapour-proof flexible plaster or paint system.
3) Too much salt in the walls
If there is too high a concentration of salts in the walls (more than 100 mg/liter of nitrates and 250 mg/liter of sulphates), we recommend treating the walls with a vapour-proof sanitizing and salt buffering mortar, more specifically RC Sanisel. This lightweight water-repellent mortar ensures that salts are stored and can no longer react, so that they can no longer damage the underlying masonry or upper finish layers.
Basement sealing with a salt problem
1) Always place a seam. Apply the primer first RC Acryplast on and place the comb wet-on-wet with DEC 2021.
2) Bring RC Salsper over the entire basement, including the seam, as an adhesive layer and salt inhibitor.
3) Apply a scald coat with 222 Lankofugeant and RC Acryplast.
4) Finish with two coats of 222 Lankofugeant with RC Acryplast as an intermediate primer.
5) Reapply RC Salsper as an adhesive layer and salt inhibitor and apply a scald layer or scrape layer of wet-on-wet RC Sanisel mixed with RC Acryplast and let dry.
6) Place a second layer of RC Sanisel with a minimum thickness of 2 cm.
7) Finish the layer as desired: use a rule and rub on or taloche and/or prepare the layer for a final vapour-proof finish (plaster or paint system).
Reynchemie's expertise and range
Basement sealing is not an easy job. There are many things to take into account: choosing the right products and materials, respecting the correct drying time, applying the correct techniques... Also, keep in mind that every situation is different and requires a specific approach. In fact, basement sealing may not be the best solution for the moisture problem in your basement at all. Carrying out basement sealing yourself is therefore not recommended and it is better to call on a contractor with expertise who can offer a long-term guarantee of quality.
Are you a contractor and do you want to be sure of a correct diagnosis and approach? Be sure to contact one of our technical advisors via our contact page.
If you are an individual and would like further help with moisture problems in your basement, we would be happy to put you in touch with an experienced company to seal your basement.
