We need to do construction below the ground level. When the ground level is increased, the water pressure also increases. Therefore water can penetrate the wall. To stop this process, we need to do blindside waterproofing. The blindside is the exterior side of the wall. Blindside waterproofing is done before constructing the wall.
Blindside waterproofing is used to stop water from leaking inside the wall below ground level. In order to reduce the construction difficulties. After referring this guide, you will know about blinside waterproofing methods, products, and testing that we should conduct after the process.
In order to learn more about these methods, keep reading on!
Blind Side Waterproofing Methods
Consider the blind wall waterproofing. We can do it in mainly 03 ways.
- Positive side waterproofing
- Negative side waterproofing
- Integral waterproofing system
For the below-ground working areas, we have to use negative side waterproofing due to the excavation not being possible to access the exterior side of the new wall. Therefore we have to use negative side waterproofing for the below-ground constructions like blind walls, tunnels, basements, elevator pits, and many more below-ground systems.
The soil retention system is used as a support for the waterproofing process. After the waterproofing is done, we have to fill the wall with concrete. This is mainly used in vast construction sites. But for the domestic, we have to use another way to stop water from leaking to the interior.
Mainly there are two types of product categories we can use for blindside waterproofing.
- On rolls and made with synthetic plastic
- Sheet materials or bentonite
- Integral waterproofing system
More than that, there are 10 Best Building Waterproofing Methods?. You can read this and check which is suitable for you.
How to Do Blindside Waterproofing?
After waterproofing is done, you can continue the construction on it. As well, you must remember to avoid any drilling or hammering on the surface. It may damage the waterproofing of the concrete. Hence protect it.
When you select a product, make sure you have got the right waterproof warranty and its limitation. It will be a great help when there is any waterproof failure.
For Concrete Walls (Large Site)
Before applying the blindside waterproofing, we need to clear the surface. Then cover the whole area with a relevant waterproofing sheet. And make sure to cover all tiebacks properly. And also, the seams of the sheet should be covered properly. After fully covering the walls and floor of the foundation, pour the concrete. Then waterproofing will be adhered to the exterior wall surface and act as one object.
- Cold joints
- Expansion joints
- Foundation drains
- Structural connections
- Damaged membranes
- Transitions and changes of condition
For Domestic Application
If there is any blind wall in the domestic, it will generate water leaking problems. So just you need to know the reason for that. For the domestic, you no need to follow advanced methods. You just need to follow the below steps.
- Remove the plaster and open up the wall bricks or blocks
- Then mix the “PERMA HYPERCRETE’ with the small sieve-size sand and cement
- Cover the whole area with the plaster mix. 3mm thickness (PERMA HYPERCRETE will reduce the setting time of the plaster. Hence do part by part)
- Let it dry for 3-4 hours. If there is water, it will take a few days due to curing
- Then apply the TEPERCRETE on it.
- After the curing is done, apply the normal plaster to it.
If you do the waterproofing with wall construction, you can use bentonite for the negative waterproofing method.
Waterproofing Technologies for Blind Side Waterproofing
As we discussed above, we have 03 main categories for the waterproofing blind side of the walls. Those are Sheet membranes, Bentonite, and integral waterproofing systems.
Sheet membranes with synthetic plastic
- These are sheet membranes consisting of materials like polymers, modified asphalt, HDPE, Pvc, Rubber, etc.
- Create a mechanical or chemical bond with concrete
- Need skilled labor
- Uniform thickness can be maintained.
- This is a naturally occurring product. It is a clay that has to potential to store 15 times of water of its size as it is hydrated.
Integrating With Concrete
Chemical adhesion: Manufactures market different proprietary compounds that are applied to the membrane face. Release paper protects the membrane until the concrete is poured, which then allows the membrane to properly bond with the concrete.
Mechanical adhesion: When concrete is poured, it will be bond with the geotextile layer. Some materials will soften due to the heat of hydration as the concrete cures. This creates an additional bond.
What is the Best Technology for Blindside Waterproofing?
Considering all factors, the best waterproofing depends on the site condition, durability, site access, applied conditions, cost, and test standards. These factors highly affect the best waterproofing technology every time. Considering all the above factors, you can select the best waterproofing technology as you need and your compatibility.
Read More About – 09 Steps to Waterproof the Basement: In | Out | Drainage
Tests Methods for Blindside Waterproofing
We have to follow the international methods for the project. There are many test methods. ASTM is the most popular and used method in the world. So we have to follow these methods. Each and every product has followed the ASTM test methods, and you can use the product as it matches the site requirements and ASTM standards.
According to your site condition and environmental condition, check whether your product is capable of adherence. Some products are designed for specific conditions. So better you select a product, you had better pay attention to the below factors.
- Site Condition and the Environment
- Approach roads
- Site surroundings
- Soil retention walls
- Height of the wall
- Pore Water Pressure
When depth is high, porewater pressure is rapidly high. And this depends on the height of the water table. You had better know about the height of the water table and make sure it’s maximum rising.
- Soil Requirements
According to the soil in the site, water pressure and water table will be varied. For the sandy soil, the water table will be changing rapidly than considering the dense soil. As well this is affecting the soil retention wall construction also.
- Surface Loading
When surface loading is increased, the water pressure also increases. Under this situation, water can be a leak if there is any crack in the membrane. Hence have an idea about surface loading.
- Temperature Changing
According to the environmental condition, site temperature can be varied. Hence the high-temperature site need thermostable waterproofing membranes,
- Maintain the Standards
ASTM is the most popular standard that we use. The standard that we use e can assure and guarantee the process for the future.
Required ASTM Standards
- ASTM D5385/D5385M-20 Standard Test Method for Hydrostatic Pressure Resistance of Waterproofing Membranes
- ASTM D5295/D5295M-18 Standard Guide for Preparation of Concrete Surfaces for Adhered (Bonded) Membrane Waterproofing Systems
- ASTM D5957-98(2013) Standard Guide for Flood Testing Horizontal Waterproofing Installations
- ASTM C981-20 Standard Guide for Design of Built-Up Bituminous Membrane Waterproofing Systems for Building Decks
- ASTM C1471/C1471M-05(2014)e1 Standard Guide for the Use of High Solids Content Cold Liquid-Applied Elastomeric Waterproofing Membrane on Vertical Surfaces
- ASTM C836/C836M-18 Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course