1. Rising Damp
Rising damp rises into the mortar, bricks and plaster. This is due to poorly installed DPC - (damp proof coarse).
Damp and moisture by passes DPC (damp proof coarse) and enters into the wall by capillary action. This is the effect you see when the paint starts to bubble and a “white”residue is visible – ( hydroscopic salts) . This kind of salt attracts more moisture.
2. Adhesive properties leaves the building.
Damp leaches the salts out of the mortar, plaster and bricks. These salts are an integral part of the glue keeping the building together. Damp + Salts = expansion (6x the normal volume of the molecules) creates blisters & bubbles.
3 . Bubbling of paint.
The accumulation of salts on or close to the plaster or walls surface and the expansion of the molecules, causes the paint to bubble and blister (efflorescence). fflorescence is the same as osteoporosis of the cement or plaster.
4. How high does the wall suck.
Yes the wall sucks, capillary suction that is. Gravitation will equal out the capillary suction at 1.2m higher than the highest ground/floor level. So if the bubbling paint is only 30cm high, it can still go up to 1.2m above the highest level. Historically contractors, DIY enthusiasts and home owners have being brushing, sanding and high pressure hosing the blistering paint off the wall. They then further apply a damp sealant onto the surface before repainting the wall.
This method or methods do not work and in virtually every instance the blistering paint will come back within 2 years!!!
Reasons for methods not working:
• Source of the damp has not been addressed. The salts retained inside the wall is still being fed with moisture.
• The salts inside the plaster has not been removed. Salts close to the surface are still being fed with moisture.
Remove the salts and source of damp from the equation and you will have blister free walls.
We offer damp solutions on lateral damp,rising damp and descending damp.
Product house: Dampsure and Safeguard Chemicals