Most of the time they do not.

Healthy isn’t a quality that pertains to load bearing-ness.

Also, a frame structure is a load bearing structure.

Most likely, no.

Granted there are a number of different materials used to pressure treat wood. Unfortunately, many, most really these days, contain copper which is reactive with aluminum.

So, if you want aluminum at your pressure-treated wood you either need to change to a different type of wood (redwood or cedar, but neither does as good as pressure treated) or you need to provide a barrier material like a bitumen tape or other non-reactive barrier.

There have been some great technical answers, so let’s see if I can dumb this down further.

Basically, a magnitude 0 earthquake is a very small earthquake that scientists use a baseline. Just as the number goes up for a more powerful earthquake going down below 0 just means that it is less powerful than the baseline.

We usually don’t define pitches as walkable, but rather how accessible they are.

Generally, the range is as follows:

Less than 1/4:12 can be considered flat for walking purposes.

1/4:12–1:20 is considered an incline where even a disabled person can ascend without aid.

1:20–1:12 is considered to require handrails to assist a disabled person.

Normally, that’s where the list ends, but there is more information.

At 3:12 you need surfaces that aren’t smooth because the presence of water, even dew, creates slippery conditions.

At 5:12 vehicles need to be rated as off-road or there are unlikely to be able to ascend.

At 7:12 most people require stairs or additional equipment to ascend.

When you get past 7:12 most people will find a vertical climb (0:12) easier than hiking beyond 7:12.

No, but a lot of people weld aluminum incorrectly.

Enter the TIG welder. This uses a heated tool called a wand rather than a torch (though it is still called a torch in some areas) with your rod as a separate tool.

The problem with aluminum is that if welded by conventional means it forms gases within the weld literally foaming inside the molten metal. This creates a weakened weld.

So, if done correctly using the correct tools, no. If you try to weld it like steel or other materials, yes you are very likely to weaken the material.

Typically recovered brick (used brick) is recovered after normal demolition practices. This means using a backhoe or such to tear down the wall, though this can also be accomplished using hand tools. That will remove most of the mortar through mechanical action with the rest chipped off by hand. This leaves a lot of rounded edges, chips, and gouges in the brick. This is the nature of used brick and is found as desirable traits.

If you want new bricks with straight lines and sharp edges you are better off getting new cut bricks.

If you are simply trying to save money. Recovering the bricks from a wall yourself is only the cheapest option if you are doing the whole thing yourself. But, this is a labor-intensive process.

Depends on where the construction occurs.

In residential areas there are curfews on when construction can take place. In areas were you get less usage and construction noise won’t bother anyone it tends to be more acceptable.

Large industrial sites may operate at night due to isolation.

Freeways can because they are designed to direct sound away from neighboring areas.

Commercial sites are a mixed bag and rely on local directions.

If you are using the river rock as veneer most will come in around 4″-6″ thick. Smaller and you start to get more into the pebble area of rocks.

If you go more than 6″ thick you might as well construct the wall out the rocks as tying to a wall starts to get tricky due to weight. Seriously, if you don’t know what you are doing with large rocks you can collapse your wall.

Maybe it’s the way the question was asked, but these two aren’t mutually exclusive.

Wood pulp-based materials are any composite using wood fiber. Fiberboard, cementitious fiberboard, OSB, plywood… There are materials people still call fiberglass when the fiber is actually wood fiber.

Rigid can be tough as it doesn’t have a universal definition. Some materials are rigid because they support their own weight while other definitions call materials rigid under certain loads or types of flexure.