Choosing the building system for a certain wall depended on several conditions, costs, time of construction, nature of resources, binding materials, building techniques a.s.o…So there were no rules that would immediately define the solution to adopt, although the geographical location seems to be the most influent factor.

Thus:

- In the north of the country, granite is predominant, so it is the most used rock.
- In the centre, schist is predominant.
- In Lisbon and Alentejo, limestones are predominant.

The stones used in the walls of the old buildings were usually bound by lime mortar

We can divide stone pitching with filled joints walls in three groups:


- Not cut
- Cut
- Double face


Not cut

Not cut or common (normal), are walls made of rough, angular and irregular in shape and dimension stones, or rolled stones, held together by normal mortar.

This type of construction is spread all over the country, but prevails in the centre and in the Lisbon area. Probably because this kind of material is abundant and found in demolitions. It is usally plastered and whitewashed to protect it from atmospheric agents, namely water.

In perpend - that is regular, and cut to the effect, layed and held together by mortar or simply put one on top of the other. Masonry all the widht of the wall, with the four sides cut.

Mainly in the north of the country, and visible.

Double face

Wall of mortar stone, usually irregular and angular shaped, layed in two layers, one internal and the other external, filled in between by small size material, with commom mortar.

They were braced with wooden or iron links that crossed the wall, preventing lateral collapse.