Wall dampness on the cement-plastered masonry walls in the residences is a very common problem. Dampness is caused by moisture in the air or seepage of water. This is a global problem, affecting around 50% of homes in some form or the other worldwide as per statistics of WHO (World Health Organization). You will get the solution of the wall dampness problem here and will be able to repair the dampness on the wall of your home.
What is the effect of Dampness in Wall??
A damp wall may result in to various major issues like:
- deterioration of plaster and paint of wall
- structural damage
- health hazards
- unpleasant odors
- damage to belongings
- increased maintenance cost
Hence, if not treated on time, the dampness of walls subsequently reduces the value of the property. It is utmost important to address the issue of damp walls to maintain a safe and healthy living in a property.
Dampness in buildings increases the risk of asthma and allergies. As per a statistics from World Health Organization, dampness can lead up to 30% higher prevalence of respiratory symptoms in human.
What Causes Dampness in Walls?
Cement plastered walls face dampness for a number of reasons. Some major reasons that causes of dampness in walls are:
- Poor waterproofing: For ground floors of a building, if the groundwater table is high in the location it would require proper waterproofing of the underground structures. Dampness can raise from ground level also through capillary action, absorbing moisture from ground to the walls. For top floors, the roof waterproofing is important to prevent dampness of the slab as well as the walls.
- Faulty drainage and leakage of pipelines: This reason is prevalent for the internal walls adjacent to toilets, kitchen and other areas where drainage lines exist. Any leakage
- Areas with high humidity and poor ventilation: Condensation can occur on walls, causing damp patches.
- Inferior quality building materials e.g. low-quality bricks, sand with impurity and use of inferior cement-sand mix can cause dampness in the walls.
How do You Treat Dampness in walls?
Does dampness weaken walls? Yes. A lot. But, with a little precaution you can easily prevent your walls from dampness. To know how to treat damp walls externally as well as internally you need to first understand what is the root cause of dampness? It is caused by moist weather and leakage of water from a source. So, to prevent dampness it is important to arrest these two major reasons.
Take care of ventilation during the design and construction
- First, while designing the house, take a note on the ventilation of it. There must be sufficient openings on the walls for sufficient air and sunlight circulation, so that it becomes tough for moisture to stay within the room.
- You should allow cross ventilations also, by placing doors and window in opposite sides of the walls.
- Placing the windows on the right direction (of wind) will have a positive impact on the rooms and prevent moisture to stay.
- You may use exhaust fans in the toilets and kitchens to keep the air circulating
Prevent water leakage or waterlogging
- During construction work, take a note of the plumbing pipe joints. All these joints must be sealed in a proper manner so that there would not be any occurrence of leakage of water within the wall.
- Take care of the drainage system properly so that there is no waterlogging on the terrace or utility areas. Slope of the surface must be proper to discharge water to the right place.
- Provide downsprouts and gutters at appropriate places for better drainage.
Give your building a Damp-proof course (DPC)
A proper Damp-proof course of DPC while constructing your house would be an excellent barrier to dampness rising from the ground. You can use bituminous felts, HDPE sheets, or liquid chemical DPC while constructing your house to get good results.
The old practice of giving a DPC is with a 40-50 mm concrete layer (Cement : Sand : Stone Chips ratio 1:2:4 or 1:3:6) with a layer of bitumen on it. But it is quite cumbersome as well as expensive in comparison to the modern day techniques like DPC membranes (available in rolls) or liquid chemical DPC. Use DPC membrane rolls in between the brick-layers on the wall, continuous below the plinth level. For best results, provide 150 mm overlapping of sheets at their joints.
DPC membranes must be carefully installed around any wall penetrations such as pipes and cables to maintain the continuity of the barriers. Price of DPC membranes varies from Rs. 50 to Rs. 70 per square foot. Find the length of the brickwork, multiplied with the width to calculate the costing per square foot.
Use waterproofing materials in the cement plaster for wall dampness treatment
Another useful technique to prevent moisture from creating dampness is to use a good waterproofing compound in the cement-sand mix while doing the plastering work on the walls. You can apply this method while doing the external walls to prevent the rainwater seepage through it, and on the internal walls around toilets or utility areas to prevent the water from any leakage of pipelines going through the walls.
As an example, Pidiproof LW+ is such a chemical that you can add to cement plaster of walls as an effective waterproofing compound. Another good product is Conplast WL Extra which can be applied with the similar process of the earlier. Dosage of both is same, 200 ml per 50 Kg (1 Bag) of cement.
How to use Pidiproof LW+ and Conplast WL Extra
Pidiproof LW+ is an integral liquid waterproofing compound composed of surface active plasticizing agents, polymers and additives. You can use this compound (at prescribed dosages) in both concrete and cement plaster.
Pidiproof LW+ is available in packing of 200 ml, 1,5,10,20 and 100 Ltr. Only 200 ml is required per 50 Kg bag of cement.
Cost of waterproofing of cement plastered walls for damp wall solution
The prices of Pidiproof LW+ and Conplast WL Extra are almost same. The price is approximately Rs. 140-150 per liter. Recommended dosage is 200 ml per Bag (of 50 Kg) of cement.
For example, if you want to use it on a 12 mm (0.012 meter) plastered wall of 10 feet (3.05 meter) wide and 11 feet (3.35 meter) high wall,
the volume of cement-sand mortar is = 3.35 x 3.05 x 0.012 = 0.123 cubic meter.
For a cement-sand mix of 1:4, cement required = 0.123 x 1 / (1+4) x 28.8 x 1.33 = 0.94 Bag.
So, cost of waterproofing compound (Pidiproof LW+)
= 0.94 Bag x 200 ml /1000 x Rs. 150 = Rs. 28.20
So, cost of waterproofing compound (Pidiproof LW+)
= Rs. 28.2 / (3.35 x 3.05) = Rs. 2.76 / square meter of wall (one side)
This is a very cheap option to protect your wall from seeping water and thereby causing dampness.
Read More: How to Save Cost of Constructing your New Home?
How to treat damp walls internally: Remove dampness from walls where dampness has already occurred?
For an already damp wall, there is nothing to worry. You can fix it with a simple process as given below:
- First, identify the area affected by the dampness. Keep in mind that only treating the damp area will not be fruitful as moisture will percolate through the next weaker area and create dampness on the wall adjacent to the treated wall. Hence, it is important to treat the whole wall at once so that water does not get the path to percolate.
- Remove the paint and plaster of the wall with a trowel.
- Mix the required quantity of cement mortar with cement and sand, 1:4 by volume. To maintain the ratio use any pot and take 1 part of cement, 4 parts of sand (properly sieved and deleterious materials removed). Dry mix for 1-2 minutes.
- Add 75-80% water to the dry mix and mix it for 2-3 minutes.
- Now, mix waterproofing compound in the remaining water as per the required dosage, then add it to the mortar mix and mix for another 2 minutes.
- Apply the homogenous plaster mix on the wall and give it an even finish.
- Start watering the wall after 24 hours of application of cement plaster and keep watering it for next 7 days.
- After 7 days, keep the wall dry and then apply good quality cement putty or Plaster-of-Paris on the wall.
- Apply paint of your choice on the wall.
Safety precautions to take while using waterproofing compound for a damp wall
Use rubber hand gloves & safety goggles, while using the waterproofing compounds. In case it has been exposed to your skin, wash your skin with plenty of water. Keep the chemical out of the reach of minors.
Conclusion
Damp proofing walls is of utmost importance in order to take care of the whole structure including appearance and strength. It is cheap but need on-time attention.
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