Curing Damp Walls DIY Guide by Donovan Bezuidenhout
As with any damp issue, one must always find the source of the damp first before you can proceed with curing damp walls. Consumers tend to “paint over” or “fix” the paint problem but not the actual damp problem. This causes further problems as the constant supply of moisture is then diverted and migrates to wherever it is able to. Plascon Dampseal is unique in the way in which the product reacts with the moisture in the surface forming an impenetrable barrier through which the movement of water and dissolved salts is not possible. The salts are found in the cement plaster, and when damp, these salts get trapped beneath the paint film and cause the paint to discolour and lift.
Curing Damp Walls: Finding the Source of the Damp
It would be of value to know where the damp in a wall is occurring, lower wall or middle wall and whether the other side of the wall is interior or exterior. If interior, what room is on the other side, such as a bathroom? If exterior, are there pipes running in or on the walls? Are there taps and gully’s? Is it a North-West facing wall (driving rain side)? Is there a garden with an irrigation system close or next to the wall? Is the water (if any) able to run-off easily and is the level of soil higher than the floor level of the kitchen? If the damp is occurring closer to the ceiling, then there are possible roof or parapet wall leaks.
I suggest you scrape the existing paint off the affected area first, down to the plaster. If the plaster is very dark grey in colour, then the wall is excessively wet. If so drill holes into the plaster to allow moisture to escape and place a fan close by if possible. Fill holes with exterior Polycell Polyfilla and not interior Polyfilla as it is gypsum-based and water sensitive. If the plaster is light to dark grey then you can proceed with the Dampseal application.
Curing Damp Walls DIY Guide
Divide the affected area into 3 horizontal sections with the top section extending at least 30cm above the affected area. Ensure that the area also extends by 30cm to the left and right of the affected area. Treat the lower section by applying a thinned coat of Dampseal (3 parts Dampseal to 1 part turpentine in volume) and allow 24hrs drying and curing time. Repeat the process for the middle section and the top section with 24hr intervals. After 3 days of application of the first thinned coat to each section, apply the second coat to the entire section and allow 24hrs drying and curing time. If using a water-based / acrylic paint you may apply the coatings directly onto the Dampseal.
PLEASE NOTE THAT THE DRYING AND CURING TIMES MUST BE ADHERED TO OTHERWISE THE PRODUCT WILL NOT FUNCTION FOR WHAT IT IS INTENDED. THIS TIME OF YEAR (IN SA) DRYING TIMES ARE RETARDED (SLOWED DOWN) BECAUSE OF THE HIGH MOISTURE LEVELS IN THE ATMOSPHERE. THUS THE EVAPORATION OF THE SOLVENTS TAKES LONGER, IN TURN SLOWING DOWN THE CHEMICAL PROCESS OF CURING OF THE PRODUCT.
- Donovan Bezuidenhout is a training practitioner for Kansai Plascon.
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