Damp/ Leakage/ Seepage: A guide to Waterproofing your Home

Water seepage or dampness of walls are common problems faced by residents. Damp can damage much more than just ruining a building’s appearance. It may lead to the deterioration of plaster and masonry, promote wood decay (rottenness of doors and windows etc.)and create unhealthy conditions for occupants.

If the construction quality is poor and lack  waterproofing measures during construction of the home than the lifetime eligibility of the home is also low. Poor waterproofing can cause dampness of the walls, puffy white deposits on walls and peeling and flakey paint.

Dampness might be caused due to a number of causes, such as rain getting through the walls or roof, moisture being absorbed from the ground, condensation settling on cold surfaces, or a mixture of these. These problems need to be tackled if you wanted to give you home a good painting experience and freshness. First of all, you should carefully determine the cause of the dampness before applying any cure on it, otherwise you could be using the wrong remedy altogether.

Air Moisture Condensation

Our modern lifestyle is one of the major reason for raised in humidity that generates big amount of water vapor, from bathing, cooking and washing. Condensation will occur on any surface below the dew point, i.e. temperature at which saturated air releases surplus moisture vapor. Condensation can be treated by reducing air humidity or keeping surfaces above dew point temperature.

If you wanted to assess the cause of a damp patch on a wall, you should go for the foil test. Dry the wall surface with a fan heater, then tape some kitchen foil tightly over the affected area. If the surface of the foil is wet after 24 hours, you have condensation. Condensation occurs when moisture carrying air builds up inside the house.

Ways  to Control Air Moisture Condensation

Poor ventilation and use of moisture-producing portable gas heaters can cause humidity. You can control air moisture condensation by: 

  • Installing extractor fans or vents in kitchens, laundries, and bathrooms so to expelled outside the moist air from the house
  • increasing ventilation by opening windows
  • avoiding indoors clothes drying

Leaks or Seepage

The main cause of dampness in the house is due to faults in the roof structure, poor plumbing including damaged or missing tiles, poor flashing and broken or cracked gutters and drainpipes. This kind of seepage or dampness is easy to allocate, as its being located either around the ceiling or on wall areas that line up with the external pipe work.

Exterior Walls Seepage & Waterproofing

Dampness and seepage in mid level walls and those around windows can be due to cracks in the external walls. It is important to repair and waterproof the exterior walls before treating the interior walls.

  • Fill cracks in exterior walls using an exterior crack sealant
  • To protect areas around window frames from water seepage from exterior walls, fill the gaps between the window frames and walls using a special bonding sealant.
  • After repairing the exterior walls for any cracks, apply any exterior paint with waterproofing abilities .e.g. Nippon Weather-shield Paints
  • https://nipponpaint.com.pk/problems-solutions

Nippon ExpressKote,  efficiently seals and regulates the drying process of the inherent moisture present in the cement plaster or concrete, thus minimizing hairline cracks and peeling, bubbling, fungus, algae, alkali and efflorescence associated with high moisture. Nippon ExpressKote Sealer is suitable for fresh cement surfaces in both internal and external conditions. https://nipponpaint.com.pk/products/sealer/Expresskote-Sealer

Roof/ Terrace Seepage & Waterproofing

Seepage and dampness on the ceiling, especially in corners are caused by either cracks in the roof or improper waterproofing of the roof. You can easily solve this issue by applying waterproofing coating on the roof to seal the leakage points in it. Drainage pipes also need to be repaired for assuring smooth water flowing. Improper or inadequate waterproofing of the terrace can lead to water seepage on the roof especially around the upper corners of the room.

  • Fill cracks in the terrace slabs so that water does not percolate into the interior walls. There are various crack sealing agents which fill up cracks with a 3 mm width up to 10mm width like Nippon Flexiseal and Nippon Vinilex5100 Wall Sealer.
  • After filling the cracks, cover the entire terrace and parapet walls with a waterproofing agent like Nippon Acrylic Wall Sealer. This product can be easily applied on roofs and gives good waterproofing without the hassle.

Seepage From Bathroom or Kitchen on the Floor Above

Faulty sealed bathroom and poor plumbing work embedded in the walls also results in damp patches and leakage. Dampness of ceilings and interior walls can also arise because of water leakage from an upper floor bathroom in your own house (from the kitchen or bathroom) or your neighbor’s house. This results from overflowing baths or showers, burst pipes, the gradual breakdown of pipe joints, leaks from washing machines or dishwashers, and accidental damage. It  gets complicated while solving this problem as you need to waterproof the bathroom or kitchen at the RCC slab level.

You need to get the tiles and the tile mortar removed and waterproof the concrete slab using Stile Waterproofing Membrane. You can also use a layer of Stile Bathroom waterproofing Membrane for a more permanent solution.

Re-pave the concrete using mortar mixed with a plasticizing additive chemical like Stile Rubber Bitumen Emulsion .

Fill grout and any cracks between the tiles  using a sealing agent like Stile Epoxy Bonding Agent.


Rising Damp on walls

Rising damp affects the lower region of walls because of rising ground water within the wall due to capillary action. This causes efflorescence (white deposit) and peeling of the paint.

Rising damp usually occurs in masonry walls because of the failure or absence of a damp-proof course, although poor sub-floor ventilation and bad site drainage can also be contributors. Damp patches, bubbling paint, crumbling plaster, or powdery deposits on wall surfaces close to the floor are the signs of rising damp. The bubbling of the plaster is caused by the continual expansion and contraction of salt crystals drawn from the ground. Rising damp will only affect walls on the ground floor of a property.

Vinyl sheet, rubber-backed carpets or other solid coverings floors become damp as the evaporation of moisture from below is inhibited. One way of finding out if damp is present on walls is by using the back of your hand against the wall. Although this isn’t the most accurate way to discover the severity of the issue, by feeling the damp area compared to a dry area on the wall it can give you a good indication of how bad the damp on your wall actually is.

Usually there are horizontal brown or discolored marks that can be seen up to 1 meter in height on interior walls, also called as Tide Marks. To tackle this problem of water leaking from walls, the plaster has to be completely removed to apply waterproofing from the brick level.

  • Installation of a Damp Proof Course (DPC)
  • Break the damaged plaster on the walls up to the brick level completely. Remember to clear a patch 2 feet in excess of the damp patch.
  • Apply a waterproof coating agent like directly on the bricks according to the right procedure.
  • Re plaster the exposed patch using mortar using cement, sand and a plasticizing additive chemical like Nippon 8000 Advance Sealer.  Allow plaster to cure as applicable and dry out.
  • Re paint the area after base preparation.

Penetrating Damp

Penetrating damp arises on the exterior of a property and can cause serious damage to the building if not treated correctly. Damp patches found on the masonry, damage the internal walls of the property. Continuous and prolonged wetting of walls and external joinery arises from poorly maintained rainwater fittings, and leaks from parapet and gutters can cause significant damage to structural roof pillars. Roofs, chimneys, parapets and other exposed parts of a building are most susceptible to rain penetration. Junction in roofs are potential trouble spots, as access for maintenance is difficult.

Any other patches of damp are most likely caused by faults in the brickwork, including cracked points. If  you found patches around windows and doors, then it’s most likely due to the rain getting in through gaps or cracks around the frames. Hairline cracks in pointing and render consistently admit moisture where cement mortar has been used for repair, rather than lime. Solutions to damp patches on your wall are:

  • Keep external walls, including the pointing and the paintwork, in good condition.
  • Seal the gaps around window and door frames.
  • Clear out or cut drip grooves below windowsills.
  • Improve the drainage of the site. Make sure the surrounding ground slopes away from the building.
  • Repairing masonry defects e.g. cracks in walls, faults doors
  •  Remove excess moss and leaves from roofs and gutters

Damp patches on Interior walls can be treated without much hassle and effort, but it must not just the patches to be treated but also at least 2 feet around the damp patch area too.

  • With the help of iron brush, remove loose material around the affected area to be treated also remove patches of loose plaster if required.
  • After removing the affected patch, re-plaster the patches using mortar made of cement, sand and a plasticizing additive chemical like Nippon Hi-Bond Sealer and Multi-purpose joint compound, it will allows the plaster to cure and dry out before the next step.
  • https://nipponpaint.com.pk/problems-solutions

Its quiet confusing to decide on which waterproofing chemicals need to be used and how to apply them. In this post I tried to explain some common dampness or waterproofing issues and their causes, what waterproofing chemicals to be used and procedures that need to be followed. In this post I have discussed about the dampness problems that arises in an existing building. I will be covered in my next  post regarding preventive measures that are to be taken during construction of building to avoid dampness and condensation problems.

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