There are a lot of ways to protect the underground structure of your building from the outside. Ideally, we recommend exterior waterproofing systems, either with bituminous or synthetic membranes. However, sometimes there is no other option than to waterproof from the inside with cementitious waterproofing.
And today I want to talk to you about one simple system that you can use for successfully waterproofing from the negative side.
The great secret of success in waterproofing is that there are no secrets of success. There are only timeless principles and systems that have been proven effective throughout the decades.
Sometimes real estate investors and general contractors choose low-cost products or do not use below-grade waterproofing at all. Later some leakages came out and the only way is to treat them from inside.
So, today I would like to talk to you about how to waterproof underground concrete structures from the negative side with cementitious waterproofing.
There’s one special product that I’ve been using for years and it worked so many times for me, even in hopeless situations.
You can use that simple system and accomplish wonderful things with your projects.
I can assure you it would make your life easier and you are absolutely capable of achieving the results you want.
Just follow the step by step process.
What I’m talking about is Izoseal.
What is Izoseal
Izoseal is integral crystalline, cement-based waterproofing applicable either on the positive or negative side.
The combination of Portland cement and active proprietary chemicals
make possible a unique chemical treatment for the waterproofing, protection, and repair of concrete.
How Crystalline Waterproofing Works
Cementitious waterproofing is delivered in a 25 kg multi-ply paper bag. You can easily mix it only with water to obtain a cementitious slurry.
The mixture is then applied to the pre-saturated surface of existing
above and below-grade structures.
The active chemicals diffuse into the substrate and react with moisture in
That causes a catalytic reaction.
What is most important here is that this reaction generates a non-soluble crystalline formation throughout the pores, cracks, and capillary tracts.
As a result, you get permanently sealing the concrete and preventing the penetration of water and other liquids.
The crystalline waterproofing can protect the below-grade structures even from water under high hydrostatic pressure.
You can also use it for sealing strips at construction joints, or for the repairing of leaking cracks, faulty construction joints, and other defects.
The key to successful waterproofing is to follow the process.
Successful men and women take the time to educate themselves on how to do the right things right.
Or just know how to find the right partner who could lead them to the process faster and easier.
I’ve been studying successful experts in the field of waterproofing for more than 20 years.
And what I found is that behind the success there is always a system, which is actually very simple and very easy to apply.
What I want you to take from this is that if you use this system you can achieve predictable results that fulfill your requirements.
We are going to talk about that in a minute and before that, I want to give you some points on
Where you can use cementitious waterproofing
The cement-based waterproofing is applicable to all structurally sound concrete:
- Foundations and basement retaining walls
- Underground garages and warehouses
- Elevator shaft basements
- Sewage and water treatment plants
- Reservoirs and swimming pools
- Channels, tunnels, and bridges
- Wet areas like bathrooms, WC, etc.
How To Apply Cementitious Waterproofings
One of the most important things in waterproofing is surface preparation. I see many contractors underestimate this stage and eventually they fail.
The concrete substrate to be applied must be clean, sound, and with an open capillary system.
To prepare the surface to remove loose parts, dust, dirt, grease, soil, etc. the reason for this is it may cause pour adhesion and may prevent penetration of product.
One of the most effective methods to do this is by high-pressure water jetting, wet sandblasting or wire brushing.
The next thing you need to do is to chase out and clean the falls on concrete such as cracks and honeycombing.
Bear in mind that surfaces must be carefully pre-watered prior to the application.
The key is for the concrete surface to be damp but not wet.
The application should be held at temperatures between +5°C and +35°C
Because negative temperatures would cause frosting the cement-based waterproofing before it drys out and forms the crystalline structure.
Very high temperatures would cause it to dry out too fast, which is unacceptable.
You can choose from two methods of application either with a brush or with spray equipment.
Pour 25 kg of powder slowly into 7.5 L clean water for brush application and into 12.5 L for a spray application. Then mix up until no lumps remain.
During the application to store consistency stir mortar frequently. If the mortar starts to set, do not add more water, simply re-stir it to restore workability.
Many times I prepared too much material that I can’t use in a short period of time. Do not make that mistake.
Just mix only as much material as can be used within 20 minutes. Dispose of the mortar of which pot life is expired.
The next thing is to apply the prepared mortar in two coats by masonry brush or power spray equipment. Apply the second coat perpendicular to the first coat while it’s still “green”.
The treated areas should be protected against direct sun, wind, or frost by covering with polyethylene sheeting or similar.
I launch a webinar soon where we are going deep dive into cementitious waterproofing and I would be happy to see you there. At the end of the webinar, I’m going to answer your questions live. Make sure you won’t miss it. Click the link below to register.
For more than 50 years crystalline waterproofing has been a proven solution for the protection of concrete structures. Cementitious products are probably the easiest waterproofing materials to use. They are easy to mix and apply and don’t need expensive and qualified workmanship. Simply follow these 5 steps and you will get better bonding, solid, and durable cement-based waterproofing of below-grade structure.
Let’s build better buildings