Despite being practically invisible, buried, under the construction, the foundation is one of the more important parts of a house, after all, is this the base that will support the height of walls, pillars, beams, stone slabs and covers keeping all this conjunct well planted on the ground, so, the care on project and the execution of foundations, guarantee the economy of work and safety of to live in an unshakable place.
Your execution happens in one of the firsts work stages and besides with such digging, dirtiness and machinery, has a great importance.
The more used method is the Standard Penetration Test (SPT), which has in every meter, the removing of a sample to study the soil by a geologist that will make a historic of the area.
The Associação Brasileiras de Normas Técnicas (ABNT) created categories to be able to evaluate the soil types. They are: rocky, sandy, silty, and clay, but the most renowned engineers put that in most of them, the areas are mixed.

In more resistant areas, indicate the use of shallow and direct foundations, with isolated Sapata, which stay under the edification pillars, ran Sapata that use the same fundament, but differs in structure the walls in all your extension or stone slab Radier that expands for all constructed area and serves like counter-floor.
For foundations deeper are used BITS that are manually drilled and filled with rebar and concrete reaching to 6 meters without the guarantee of reach the rigid soil.

THE STAKE STRAUSS is filled too with ironware and concrete, but reach between 10 to 15 meters with use of light machinery;
PRE-MOLDED OF CONCRETE STAKE, it’s ready and fixed on the soil with a slam, capable of reach 5 to 12 meters, according to necessity;
TAB TO OPEN SKY is cylindrical forms with large bases that reach large deeps and is filled with armed concrete, indicated for large charges and restricted to rigid soil and without water;
 
CONTINUOS PROPELLER is an equipment like a “corkscrew”, which after drill the soil, inject concrete by a central tube in proportion that it is removed;
The WOODS STAKE are used in specific cases of awash areas with average duration of 8 to 10 years having the eucalyptus like the more used wood, your charge is determinate by thickness of every staff. 
To end the STEEL STAKES in “H” form, mainly used in buildings, but with applications in residency where the soil is too soft and the handling facility, nailing, redress and diversity on length optimize the installation time not being recommended for locals that have water contact.
(Source: Revista Arquitetura & Contrucao)

These are some of foundation types and how we can see, the soil type and the environment conditions are important in this stage, remembering that the contruction with ECOLOGICAL BRICK can be done with every foundation type. Check a specialized professional and begin to contruct.