No, it’s not legal for unlicensed individuals to conduct structural calculations for buildings or building repairs. Not only do licensing requirements prevent DIYers from tackling this project, but mistakes can also be extremely dangerous and put your property and anyone inside or near it at risk of severe injury or even death. You should always hire a licensed and certified local structural engineer to make structural calculations.

The early stages of building a house are harder than the later stages; laying the foundation and framing the house are two of the most challenging steps. However, it varies for everyone. Some people have difficulty installing HVAC, plumbing, and electricity, while others find it harder to plan the house and secure the necessary permits. 

On average, 6 inches of concrete can hold around 150 pounds per square foot, but the exact weight that 6 inches of concrete can hold depends on factors such as the type of concrete, the reinforcement method, soil conditions below, and structural design. If you’re concerned about the longevity of your concrete patio, walkway, or driveway, hire a professional to help you choose an appropriate concrete thickness and reinforcement method for your needs.

While concrete walls do not need to "breathe" in the traditional sense of the word, they do require waterproofing and dehumidifying methods, particularly in basements below the water table. Concrete both contains moisture from its initial installation and can absorb water when exposed. Ensuring proper basement ventilation , installing a vapor barrier, and controlling water exposure are all important tasks.