Buildings pathology

How vulnerable are materials to time?

The wood as a construction material is used in the shape of beams. The beams are used to frame overhang, framings, spans and horizontal beams put in the bearing walls. As time goes by, the wood may decay and lose its primal physical and mechanical traits. In such cases, the structural behaviour of the structure may be compromised.

The collapse of more or less wide portions of the structure may occur. Decay can be detected visually directly on the timber elements which start to disintegrate or because plaster starts to fall.

Humidity caused by capillarity or water leakage can cause severe damage to masonry and painted surfaces. Capillarity causes degreasing processes in porous materials (brick, mortar and plaster) and biological decay mechanisms in timber. Water leakage alters colours surfaces and can produce soluble salts’ crystallisation (efflorescence and subflorescence), with consequent fall of plaster. Soluble salts are frequently caused by the use of cement mortars, which are inappropriate for conservation, but largely used materials.

So buildings “get seek“. They have their pathology issues as time goes by…

Activity

In the following 360° virtual tours, try to observe the pathology issues found inside the buildings. Then, solve the matching game below.

Momirovi House

This is a building belonging to the profane architecture of Ohrid. The pathology status for this building is D (30%-60%). Can you imagine what that means? Take a tour inside this (dangerous) house and roll over the places you think pathology exists:

St. Sophia Church

The church of Saint Sophia is the one you have already teleported. You know that this church dates back to 1035. This means that its materials have been exposed to the environment for many many years. Take a longer 360° virtual tour inside the church and try to identify its pathology issues:

Matching game

Match the pathology issues you see in the photos on the left with their names at the bottom. One issue has already its name placed upon. You can retry many times to achieve the best score. You can also see the definition of each pathology issue at the bullets below to facilitate your answers.

• Abrasion A surface discontinuity caused by roughening or scratching.
• Capillary action, capillarity The phenomenon responsible for dry soil sucking up moisture above the groundwater level.
• Capillary flow The flow of moisture through a capillary pore system
• Crack A building defect consisting of complete or incomplete separation within a single element or between contiguous elements of constructions.
• Erosion The gradual deterioration of a paint film due to degradation of the binder, which results in chalking, or to mechanical abrasion.
• Moisture movement
  • 1. The process by which moisture moves through a porous medium, such as wall construction, results from differences in vapour pressure.
  • 2. The effects of such movement on the dimensions of a material such as plaster, mortar, cement paste, or rock.
• Moisture expansion An increase in dimension or bulk volume of a material or manufactured article caused by the absorption of water or water vapour.

Questions

1. Can you recall any of these pathology issues inside the Momirovi House and St. Sophia Church?
2. How do you think these issues could be solved?
3. Why has the St. Sophia Church resisted time so much?
4. Do you know other similar Churches in your city that have resisted time as much?