Renovation of masonry

What it is
Rising damp is the most common type of damp found on walls and it affects both recent and older buildings, when there is no insulation or it is ineffective. It affects the lower part of masonry and it forms because of capillary upwelling of damp from the foundations of the building. It is connected to the presence of water in the subsurface, rainy conditions, size of capillaries and high wettability of building materials. Rising damp is a seasonal phenomenon and it reaches a higher point in walls during the cold season when there is reduced evaporation of water inside the walls.

How to recognise it
It is clearly visible in full masonry; the damp rings and the decay of plasters and bricks are continuous and present on all walls. They have the typical “wave” run with a height raging from a few dozen centimeters to three, four meters.

Reasons behind this phenomenon
Every building material has its own porosity which is similar to a think network of tiny channels. Capillarity is a physical phenomenon according to which water rises more the smaller the hole section is.

Damages caused
Rising damp decays both the internal and the external part of masonry. The presence of soluble salts in the subsurface or in the minerals of the masonry fosters capillary rising. Damp evaporates on the surface of the wall and causes crystallization of salts which form a skin that blocks capillaries. Pressures are generated and they result in the removal of the skin and part of the masonry material.

Esthetical damages
On the outside: mold stains and rings, damp, detachment of plaster and break up of bricks.
On the inside: detachment of paint, plasters and wallpaper, appearance of damp rings, molds and saline blooming.

Static damages
Corrosion of bricks, mortar beds and water within the walls cause with time static weakening in the oldest constructions.

Economic damages
In terms of continuous and often useless renewal operations, damages to furniture and higher heating costs due to the reduced thermal insulation of damp walls.

Damages to health
The high concentration of damp, together with the creation of molds, create unhealthy environmental conditions for the people who live in such buildings.

Restoration technology

RESIMIX, a leading company in the restoration product and technology sector for over thirty years, has developed systems for the renewal of damp masonry and for a definite solution to rising damp. These problems are widespread even though they manifest with different degrees and for this reason they must be faced with different interventions depending on the gravity of the situation.

1st level of intervention: moderate damp, slight decay: apply RESISEAL salt barrier and RESIMIDE macro-porous dehumidifying plaster which eliminates damp thereby increasing the evaporation capacity of the wall.

2nd level of intervention: high damp levels, marked decay:
creation of a “chemical barrier”, i.e. chemical damp-proof course, by injecting RESISIL 910, a waterproofing product, to create an impregnated strip which prevents damp from rising. Then apply RESISEAL salt barrier and RESIMIDE dehumidifying plaster.