RISING DAMPNESS- Ghar Ghar ki Kahani
The most common form of dampness is found in a building is “Rising Dampness”, particularly more in residential buildings. There are other types of dampness too but which needs to be identified correctly for the right treatment to be done.
Definition & Flow Dynamics
Rising Dampness may be defined as a vertical flow of water up through walls and wall floor junctions coming in from the ground. Water rises through capillaries in the masonry, where masonry behaves like a wick.
Water moves through the mortar bed and bricks/blocks. In case of using an impervious brick, water still can come in through mortar, but use of an impervious mortar may stop the water movement inside. Hence, mortar beds are more sensitive and demands an adequate treatment to avoid such inconveniences.
Ground water also contains some soluble salts, chlorides and sulphates, which also are carried away along with the water and after some days on evaporation water, these elements remain as residue leaving marks/patches up to a maximum height of 1 meter. Rising Dampness always is limited to such height from the floor level.
Corrective Measure to Rising Dampness
The rising dampness is inevitable in most of the areas, unless a proper damp proofing treatment is done at the time of construction of the building. The severity of dampness would depend on the height of water Table, humidity, rainfall, etc.
To avoid the rising dampness in totality, it is required to envelope the building with an efficient dam proofing/ water proofing treatment ensuring a complete continuity of the treatment from below ground to the retaining wall all around the perimeter, the treatment coming up from the bottom must go above the raft level. This can only be done during construction of any building only.
Any treatment related to damp proofing at below ground either impossible or cumbersome. However, as rising dampness affects the inside environment of building, hygiene of residents and moreover causing damage to the civil work, therefore, this must ne removed at the earliest.
Treatment Methodology
The suggested methodology to treat the damaged surface
A, Outside
· Digging out of the earth up to 300 mm below the ground level on all four sides
· Removal of cement mortar plaster up to 1.5 m height from the lowest level
· Allow it to dry for a day and thereafter clean the surface thoroughly. Including all joints
Injection Grouting of all joints with cement slurry admixed with non -shrink cementitious grout
· Application of a coat cement slurry premixed with styrene butadiene copolymer latex
· Building up of a plaster (when surface is tacky) of 10 mm thickness of factory made non shrink fibre reinforced repair mortar and allow it dry for a day.
Application of a coat cement slurry premixed with styrene butadiene copolymer latex
Application (when surface is tacky) of additional 15 mm thick cement mortar plaster (1:3) admired with Integral waterproofing Admixture as final layer and allow water curing to be done for 3 days at least
Backfill carefully.
B. Inside
Scraping of the plaster all up to 1200 mm height from the floor and cleaning the surface including all brick joints.
Application of a coat cement slurry premixed with styrene butadiene copolymer latex
Application (when surface is tacky) of additional 25 mm thick cement mortar plaster (1:3) admired with Integral waterproofing Admixture as final layer and allow water curing to be done for 3 to 5days
Finally, matching paint to be applied
Other types of dampness prevail in a building:
Penetrating Dampness
This is caused due to leakage of water through walls. There are several reasons to happen it, such as cracks on the walls, defective /crack door/ window frame and window sill, Beam — wall / column -wall junction, water splashing intermittent / continuous on walls thru spouts/ water outlet/ gutter (defective). Leaky plumbing joints or cracked pipes.
The treatment calls for correction of all cracks, removal and re -fixing of defective items, treatment of column — wall/ Beam- wall junction either with joint sealant or grouting with polymers and finally the adequate coating of exterior walls with elastomeric coating offering waterproofness, dust repelling and stain free surfaces.
Condensation Dampness
Condensation dampness is resulted from the condensation of moist air, warm air coming in contact with cold surface, particularly when air is cold and fully saturated with moisture and settles down as condensate and repetition of the same cause dampness on those areas.
There are several suggested methods to avoid such situation, such as formation of double-glazed airtight window, use of a dehumidifier, improvement of ventilation and installation of vents, using cyclic operation of cooling and heating (wherever possible during cold weather) and cleaning of surface on a regular basis.
Conclusion
It reminds me the same old proverb — “Prevention is better than Cure”; therefore, it is always wise to have an adequate damp proofing /waterproofing treatment while constructing the house/ building to avoid worries at a later date., There are enough experts to suggest the right treatment and recommend suitable installer.
