Damp proofing is a type of moisture control applied to the walls and floors of residential or commercial buildings to prevent moisture and mould.
Damp proofing problems are among the most frequent issues that occurred in homes now these days; they mainly occur in older buildings or poorly constructed buildings.
Often damp proofing products keep the moisture away from buildings where vapour barriers retain internal humidity in the walls.
Moisture resistance must not be absolute and defined by a specific test method, range, and engineering tolerance.
The damp proofing course can be horizontal or vertical.
Methods of damp proofing:
Damp-Proof Course (DPC):
Damp Proof Course is a fence through the structure by stripe action such as through a phenomenon known as rising damp.
Rising damp is the effect of water rising from the ground to the building.
Some types of issues: Salt Damp, Lateral Damp, Rising Damp & Mould.
There is some damp course that makes sure your damp problems could not occur again.
Silicone Damp Course:
Silicon is primarily a wax with highly effective water-repellent properties, and in Damp Proofing Course, fluids dissolved in a spirit base with anti-fungal components.
Sub-floor ventilation is to exchange moist air with fresh air.
Plastering work is a process to change the composition of the plaster, making it more likely to attract and retain moisture.
Fixing Skirting Board:
A damp or rotting skirting board or floor to get rid of growing damp problems.
Drainage is the natural or synthetic removal of floor and sub-surface water from a space.
A cavity wall consists of two parallel walls/masonry skins, separated by a continuous air space.
They consist of three parts: outer wall/leaf (10 cm thick of outer wall) cavity/air space (5 cm-8 cm) inner wall/leaf minimum 10 cm thick)
The two leaves forming a cavity in the middle may or may not be of the same thickness.
The provision of continuous cavity walls efficiently prevents the transmission of moisture from the outer to the inner wall.
Under India’s climatic conditions (hot-dry / hot-humid), cavity type construction is most desirable as it offers many advantages such as better living and resting conditions, occupational structure and protection of buildings against moisture.
Shot Concrete (Gunting):
It consists of forming an impermeable layer of enriched cement mortar (1: 3) for damp proofing on the exposed concrete surface to withstand water pressure.
Gunning is a mixture of cement and sand, with the usual ratio of 1: 3 or 1: 4.
A machine is known as a cement gun, which has a nozzle for spraying the mixture and a drum of compressed air to force the mix under the desired pressure.
Any surface to a given treatment is first thoroughly cleaned with any dirt, oil, or loose particles and then thoroughly wetted.
A mixture of cement and sand provided with a pressure of 2-3 kg / sq cm by holding the tip of the cement gun at a distance of 75–99 cm from the wall surface.
The impermeable surface should besprinkle with water for ten days.
Causes of Damp Proofing in roofs:
- Poor quality of construction material.
- Bad design.
- Fault in construction.
- The rainwater falling on the outer walls, the parapet, also causes moisture.
- If the roof is of low quality, rainwater can also enter into the house.
- Small roof slopes or faulty junctions between roof slabs and parapet walls can cause damping.
- Leakage through down passes can cause moisture.
Advantages and Disadvantages of damp proofing:
- The use of cement leads to a better water system.
- It gives the roof a reasonable slope.
- It is durable and sustainable.
- It repairs other voids or cracks that are already present in roof slabs.
- Normal cracks sometimes develop in this damp proofing process.
- Also, it provides additional weight to the entire structure.
- It leads to the level problem.
- Sometimes it creates ugly patches up to the roof.
Frequently Asked Questions:
How do you damp proof a wall?
1. Cut moist proofing membrane for size.
2. Place a damp proofing membrane on the wall.
3. Fold the damp proofing membrane around the corners alternately.
4. The drill then fixes the damp proofing membrane to the walls ensuring a tight fit.
Is damp proofing expensive?
Across an entire house, the cost can increase when you need to treat every wall.
This can be cheaper if you have separate plastering and decoration after treatment.
What is the difference between damp proofing and waterproofing?
The purpose of damp proofing is to keep soil moisture out while waterproofing keeps both moisture and liquid water out.
When should I use damp proofing?
If you live in a dry climate, have strong control over the quality of work done in preparation and have the ability to have drainage facilities with earth moving equipment to backfill the foundation or to control hydrostatic water pressure, Choose damp proofing.
Moisture gives involuntary condition in addition to a decrease in the strength of structural components; the provision of damp proofing courses prevent the entry of moisture into the building.