Why cement-based DPC is not the right solution for damp proofing
The protective layer known as Damp Proof Course, or DPC, is applied to stop capillary action from bringing moisture up to the walls from the ground. It typically has a thickness of 2.5 cm or more and is made up of rich cement concrete mix in a ratio of 1:1.5:3 or with cement mortar in a ratio of 1:2 with standard waterproofing material or admixtures either powder or liquid based. It extends all the way across the plinth wall, around the plinth level.
Common materials for damp proofing the structures are as follows:
• Flexible Materials: Materials like synthetic sheets made of plastic, bitumen felts made of hessian or fiber/glass fiber, and so on.
• Material that is semi-rigid: materials like asphalt, mastic, or a mix of different materials or layers
• Un Reinforced Materials: Stones, first-rate bricks, slate, cement concrete, and other materials
During cement’s hydration, the process of curing is used to control the loss of moisture. Hydration takes time – days or even weeks as opposed to hours. Curing needs to be done for a good amount of time, like a week or more, in order for the DPC to be strong and durable. Insufficient curing will lead to weak concrete that is subject to cracking, abrasion, and adverse effects of changing weather conditions. The unequal settlements and movements within walls and their foundation is also a challenge DPC layer to withstand for.
Weak DPC will develop cracks leading capillary moisture to rise and creating dampness in walls. Dampness is the cause of many structural and property issues. Dampness will eventually lead to rot in the frames of doors and windows, weaken the wooden floors, and weaken walls with efflorescence. Mould and fungus will pollute indoor air quality and can lead to many respiratory problems. Mould’s effect on children, pregnant women and the elderly is of great concern. The NHS states the following groups to be more sensitive to allergens: Infants and young children, the elderly, people who already have skin conditions like eczema, people who have respiratory conditions like asthma and allergies, and people whose immune systems are weak.
Therefore, it’s crucial to address damp concerns before they get severe enough to result in these expensive complications. Repair any cracks as soon as you see them, fix damaged guttering, and use a dehumidifier to lower the air’s moisture content to eliminate any places where moisture can cause harm. Most home insurance policies for buildings and possessions exclude coverage for damage due to dampness and condensation.
Looking at the many challenges with cement-based DPC it is advisable to opt for a damp-proofing solution like DampX at the construction stage of the walls itself that mitigates the risk of rising dampness weakening the structure and posting a threat to health. DampX is a high-performance and robust, fully bonded, composite elastomeric terpolymer damp-proof membrane.
Let’s compare DampX’s advantages over traditional cement-based DPC:
- Effectively keeps dampness and moisture from rising inside the structure
- Prevents the growth of mould and fungi on the walls
- High flexibility for corners and superior junction coverage.
- Extremely robust to weather conditions & traffic
- Due to the simplicity and quickness of installation, it saves time and money
- High resistance to wear and tear because of its composition
- Provides stability and long service life due to its monolithic property where it bonds to the substrate
- Excellent resistance to moisture, acids, alkalis, and UV rays
Here’s a detailed comparison guide between DampX and other DPC materials: https://krubber.co/wp-content/uploads/2022/10/DampX-Comparison.pdf