The scope of the planned labor is described in the original contract, and the procedure for a change order is also described, and that includes unfortunate surprises. Those unfortunate surprises may need to be taken care of by a specialty contractor, such as an exterminator, or a structural engineer if signficant damage is discovered. What usually happens is that pretty much all work stops until the new problem has been figured out. "Figuring it out" may include your GC overseeing the fix, or another contractor and it may include you dipping into your reserve funds to account for the work needed. In some cases, it also includes reassessing the specs of the rest of the project because the problems found were so extensive and were so imperative to repair.

The best way to avoid surprises is to do some investigating of your own prior to planning a project. The age of your home will determine whether or not it might contain knob and tube wiring, for instance, and a quick hole in the drywall of a soffit can determine if it contains pipes or HVAC ducting. Your previous repair history will help determine other potential issues such as if had a water leak and know for certain that you have 50 year old galvanized piping that will need to be entirely replaced sooner rather than later. And some things, like hidden termite damage, can be avoided with a proper inspection by a professional along with a contract to keep the home termite free. In fact, just keeping up with proper home maintainence (like draining your water heater annually) can teach you a lot about your home's needs before any repairs become necessary. And maintainence is much cheaper than repair and keeps those unknown problems to a minimum.

Thank you very much. Okay then, in the crawl space (eww and ick), in the attic, and a few holes to scope out the lay of the land. The house is new to me and was vacant, so there is no repair history.

I will presume certain facts about an almost 50 year old house knowing it needs a lot of work and proceed from there.

Remodeling contains unknowns. Termite damage, for example. In new construction, it's usually the homeowner-to-be changing their mind from the original drawings. "Can we move that window over here?"

The basic contract should contain the basic scope of work to be performed under the existing "as known" conditions of the house, with provisions to deal with the unknown cans of worms that might be uncovered as the layers of the house are peeled back.

As live wire wrote, unexpecteds are usually dealt with by issuing "change orders". Essentially a mini-contract to address the additional work listing the scope of work, how much, who does the work, signed and dated by both parties.

Typical can-of-worm costs (unforeseen and hidden damage, changes of mind) are paid for by the homeowner.

In remodeling it's crucial to have a budget buffer just in case.

I have had two clauses in written contracts.
One covers smaller changes (and occasionally hourly rates for change work) and another for larger items.

I have had work come to a stop for months when 'gotchas' were found on demo and the owner did not have funds for the required repairs.

This is one of those times it is very good to have an ongoing relationship with the GC.

For minimal expense I got the kitchen back to functioning (if not the best appearance) until the work could be completed.

Having a more detailed contract cuts both ways.
While it can provide some cost control (but often not everything) if the owner pushes to hard EVERY change becomes a change order (no matter how minor).

While there are plenty of 7-4 workers, there are also plenty who put n extra hours to make sure the job is done correctly and in a real crafts-manlike manor.

A lot depends on what is actually found.

I can handle minor structural issues, but will likely need additional labor and permits for major issues (like the major beam failure found in one 1780s house it really was a wonder the place had not dropped the second floor into the living room).

A whole lot of cribbing and then we figured out how to fix things.
While the owner was less than thrilled with basement and living room cribbing to hold up the second floor, it all worked out well.
The cribbing made replacing the beam far easier.

I frequently babysit my grandsons so I think cribbing is putting a larger piece of lumber (maybe 2x8 or 2x10) on top horizontally and bottom with smaller (2x4 or 2x6)vertically to support the roof/upper floor. Is that right?

Maybe I need to purchase a book that has a glossary of contractor jargon.

Okay so then is there a type of inspector who will look specifically for the problems behind the walls?

Making changes are expensive; this I know. I plan to not change my mind on any of my decisions after the contract is signed, but I have no control over the hidden surprises and would like to limit them as much as possible - if that's possible.

We've been advised in the past, especially with going into the walls (and double especially with structural walls) to plan for a contingency reserve fund of 20%. Not what you wanted to hear, I'm sure...

On our big restoration project, we spent it:)

"I frequently babysit my grandsons so I think cribbing is putting a larger piece of lumber (maybe 2x8 or 2x10) on top horizontally and bottom with smaller (2x4 or 2x6)vertically to support the roof/upper floor. Is that right?"

That sounds more like a temporary wall.
Top plate, bottom plate, studs.

Plates may be large to spread loads onto a larger area then a simple 2x4 plate.
Sometimes you even have to go down multiple floors ading temporary walls till you get to a foundation you can spread the load on.

Cribbing is a pile of larger piece of lumber with at least two pieces per layer, with each layer 90 degree to the one below.
I have a pile of 30 inch long sections of railroad tie (~8x8) I use most of the time.

Some smaller stuff at the top as needed, and even shims to make the stack snug.

While most of my clients have other funds they can get, a major problem can exhaust that.

The cracked beam ending up costing more then the rest of the work.
Having historical preservation folks from the city involved on an interior problem did NOT help.
They had to 'review' everything, despite it not affecting the outside appearance of the place.
Mostly they added a weeks of delay.

When we had the basement remodeled, I started the demo. That let us know what to expect: we could see the termite damage (it didn't go up to the floor joists above) and the wiring. We had a very good plumber replace all of the pipes before we brought in the contracting company.

I guess it depends on whether you can live with the mess, but doing your own demo really saves $$ and lets you get a jump on some "surprises."

I would like to think that I could correctly complete a significant amount of my own demo. However... One of my favorite DIY shows is 10 Grand in Your Hand, and the best advice there is to be sure that can actually do the work because you WILL be charged more for someone to come in and fix your errors. I shall take that advice to heart. Some things I can probably do, but... better safe than sorry.

Demo can range from 'have at it' and tearing stuff out to careful 'deconstruction' to minimize collateral damage.

Cleaning all the plaster from a stud wall is easy, but dirty.

Tearing one side wood lath plaster from a stud wall can require care to not damage the side you are trying to keep.

It all depends on your capabilities and what tools you have (or can get) to compete the job.

There is also some knowledge and planning required.

Simply smashing a plaster wall into pieces makes a huge amount of dust and debris that must be shoveled out.

Cutting the plaster into larger pieces produces less overall dust, and makes for fewer (larger) pieces that can be carried out one by one.

Tools and planning - I've got that; the actual knowledge? Not so much. How do you know where the wires and plumbing are? Even if water, gas, and electricity are turned off, I imagine one still must be super accurate about their placement inside of the walls.

I positive that demo in real life is not like a DIY show.

"How do you know where the wires and plumbing are?"

Look at what is above the wall section and look up from the basement.

Assume every stud cavity has at least some wiring (most will) and possibly plumbing if a bathroom is above or nearby.

Start with a small opening into the cavits about the middle of the wall and then use a mirror and flashlight to look around insode the stud cavity.

If there are horizontal 'fire blocks' in the wall, cut just above and below them to look up and down.

A Sawzall used at a shallow angle to the wall surface can be used to cut though just about any wall material, but avoid just jamming the blade in at 90 degrees and cutting an opening until you know what you might hit.

For drywall, veneer plaster, or 2-coat plaster a RotoZip set to barely the wall thickness is very safe to cut openings with.
You may need to run a utility knife in the RotoZip kerf to finish cutting through.

For serious investigation flexible and rigid bore scopes can be used (and there are some lower cost ones coming on the market).
They are more useful for trying to figure out how much work it will be to remove things like kitchen soffits.
A small (1/4 - 1/2 inch) hole lets you look around inside the soffit and is easily repaired if desired.

demolition or careful deconstruction.. either way, it's the easiest part of the whole process. Don't spend money here if your budget is tight. Also, it seems you have the time and the interest to do things right, by yourself, as much as possible. Your goal initially is to know where pipes and wires are, and to know which of the structural elements must remain and which are optional and can be removed.

You can bang open a hole, and break the stuff near it to make it big enough to see around inside the wall cavity. Tape a large piece of paper over it while you are still in the planning stages, so you have less ugliness to get used to, and less dust. There is fine dust inside the wall cavity, so you would rather not leave it open for a few weeks or months while you plan your plan.

If you decide later to keep that segment which you might have originally thought of removing, don't worry about the holes you will make. Patching a hole is easy.

Before breaking holes, you can look from the basement and utility spaces. It's useful to do this, for a few minutes, no matter what. An experienced person doesn't need more than that. After the first ten minutes there is not much point to keep looking at things from the basement view and from other places. Get a few experienced guys to walk around and comment where things probably are. In the end you will have a couple competing "theories" about where one or two of your pipes are, but not a dozen different theories. Some people are good at sensing where pipes are, in advance, with almost no clues to guide them. For electrical, no-one will be able to spot the routes of all the wires, exactly, in advance.

What brickeyee wrote was all good, but too detailed for you at this stage in your process.

Hth

Quote: " I imagine one still must be super accurate about their placement inside of the walls."

ae2ga based on my reading of this remark, I think you may be overthinking. Just break open a hole, and then another one. Don't stop after two holes. Make a third one. Use any dumb method that you feel comfortable with. A little hammer, a big hammer, a rock from the garden. Anything.

Oh! Well then I suppose I may not be able to take down drywall from the ceiling, but I can certainly do the walls. Thanks!

I need to add one more step in the explanation:
Your goal initially is to know where pipes and wires are, and to know which of the structural elements must remain and which are optional and can be removed, _AND_ this is the reason why you open some holes. Nobody does the opposite. Nobody knows everything there is to know before opening the walls. They always start with a hole in any case. (Maybe they then proceed immediately to "demolish", but they honestly do start by making a hole.)

Later, you can continue removing wall stuff and toss it more and more of it into the garbage each week.

For you, in the diagnostic and fact-finding stage, opening several holes is a necessary step, unless you can be convinced in advance that you know enough about what "there is" behind the walls. At the very least, opening holes will prevent any wannabe GC from saying that things might change later "after we see" what is behind the walls.

Hth

If you have drywall use a RotoZip (set to the drywall thickness) to cut the openings, and SAVE the cut out pieces.

They are the perfectly matched patches if you then need to close up the opening (permanently or temporarily).

"For you, in the diagnostic and fact-finding stage, opening several holes is a necessary step, unless you can be convinced in advance that you know enough about what "there is" behind the walls. At the very least, opening holes will prevent any wannabe GC from saying that things might change later "after we see" what is behind the walls"

That is an excellent idea. I may be surprised and unhappy with what I find, but I'll know before the GC comes to give an estimate for the work.

@Brickeye - cool tool! Thanks for the recommendation.