Drywall

The terms Exterior and drywall are not compatible. Drywall is used on the inside of the wall and is protected by a suitable weatherproof surface on the exterior of the wall framing such as lapboards, stucco, exterior sheathing etc. All of these have a moisture barrier behind them to prevent water/moist air from contacting the drywall. Drywall will disintigrate and allow mold/mildew and fungus to grow when moist. Eventually it will fail completely. So-called "green board" drywall is used in bathrooms and areas subjected to moisture but only outside the bath or shower area. It is not suitable for anything other than a backing material if used in the wet area of a bathroom. It can reside behind cement board or other materials with waterproof qualities. Never adhere tiles directly to green board unless it is outside the wet area of the bath/shower.

On Average the cost to install drywall in most major cities is roughly 3.00 per sqft. Of course this depends on the size of job. A simple way to cost out the price of a drywall job is to basically figure out how many sheets is required and base it per sheet complete at a cost of 100. that includes taping and finishing.

Because it is not a finished material until 2 or more parts are combined.

Either cut out a square to the center of each joist either side of the hole and replace the drywall with a new piece cut to size. then tape and mud the joints.

Also there are metallic screen patches made for small holes that stick to the existing drywall, and can be mudded over to fix the hole.

Cut drywall panels to size using a sharp utility knife. Install on the ceiling using as little panels as possible, reducing the number of joints. Use 6-Inch nails to attach the drywall panels to the joists.

One bucket will do for many sheets. It depends on how good the installers were and what tape you use. Mesh tape is better in my opinion,but does take more mud. - That's a small consideration for the better finish it will give.

everything including 5/8 drywall only requires 1 1/4 length drywall screws. you put them in 16 inches apart on the studs and in the center the same distance apart.

How big of a box? They are normally sold by weight.

Drywall mud is water based. Rub the area with a wet sponge or rag and let the water work on the drywall mud. As the mud gets wetter it will come off. Be sure the water will not damage the underlying window frame before you start.
wash it with warm water with a green and yellow scrubbing sponge

You put post protectors in the drywall, and don't do it at the end of the drywall.

There are the drywall screw anchors that just look like a giant screw, they just screw in with a Philips and then the correct size screw fits into the same place as the screw driver.

Blue (and other colours) plastic anchors you punch a hole in the drywall then push in the plastic insert until the little flange touches, then the screw goes into the center hole to expand for grip in the wall (these are good for low strength hold in other materials)

Finally there are toggle bolts, they go through a pre drilled hole and the little wings pop out and the screw gets tightened until the wings clamp down from the far side of the drywall.

All use a screw to either hold things up or clamp a hook or similar to the wall.

Paster of paris is a form of drywall, so I'm unclear on your meaning except possibly you have a wall with plaster over lath and want to cover it with drywall. You can find the studs electronically and go ahead and attach drywall to the face of the plaster with extra long screws. - Personally, I would rather repair whatever is wrong with the plaster and lath.

You should charge a fee that will include a portion of your fixed costs for such things as insurance, storage, tools, gas, and vehicle expenses. Add to that a labor fee based on the expected amount of time you anticipate the job will take. The labor fee will be based on your experience, skill level, and demand for your work. Then add a profit percentage of 10-50%. Add in also any materials you provide and mark them up by whatever percentage you think is appropriate.

Dry is not the word your looking for here! Cure is appropriate.. Stucco as with all Portland Cement based products depends on water in the mix reacting with the cement. As this reaction takes place the water is absorbed into the cement causing an "Exothermic" event [creating heat] and causing the sand and aggregate to bind together, basically forming artificial rock called concrete. Stucco is a generic name and denotes a fine sand mix texture but it has the same principal.

Once cured, a majority of the moisture has been consumed by hydration process and some is lost due to evaporation. Most engineers call for a cure period of 7-15 days to allow for a complete cure. Premature hydration or evaporation will deter a good cure and cause shrinkage cracking. Even after the cure period [to dry out?] stucco will absorb moisture from high humidity or rain. This makes it WET again !!

Allowing moisture transfer in and out of stucco is an invitation to a host of problems! If you paint stucco but still have not sealed it, moisture will bring chemistry out to the surface where it will blister and delaminate coatings. Commonly called "Alkali Burn". Waterproofing a stucco ASAP to control the cure, eliminate cracking and be able to paint in 48 hours, is what I suggest.

Personally I would get out my trammel points: these are devices that make any 3/4 x 3/4 stick of wood into a giant compass and have clamps on them and a place to put a pencil, or just get a straight piece of 3/4" stock and drive a nail in one end and a hole in the other end that would accommodate a #2 pencil, or just the point and secure it with tape at the radius you would like the arch to be, lets say 4'-0"=48". Assuming your arch is going in a non bearing wall, you will need to open the wall up to 52". Why 52 you ask? well you will have to add one jack stud to either side of your opening, that equals 3" and if you use 1/2" drywall that equals 1" on both sides, and that is 4" plus 48" equals 52". You might have to add additional king studs after you open the wall because even though the studs may be centered on 16" that will only give you 48" on center, and if you're demo-ing a door you will have to remove the existing jack, king studs and header.

Find some new header material that will handle your 49" radius, 2x10, 2x12, or plywood laminated to equal 3 1/2" to equal the width of the existing framing, you can rip a 2x4 to make 2 1/2' spacers plus 1" of plywood equals 3 1/2 wall. Why 49", because the 1/2" drywall x 2 equals 1" - equals 48", at the sides anyway. Take your trammel points, or your straight stock with pencil and measure 49" between the two and make your radius mark. Make sure you have enough plywood on top of your arch so that it matches any height openings in the room. The gross length of the plywood will be 51" so that the plywood and 2x44 template will sit on the jack studs. screw the 2 pieces of ply together and cut out with your jig saw, Sabre saw or saws-all. Lay out the spacers on 16" centers and screw them to one piece of plywood. Flip the plywood over and screw it to the spacers making sure you line up all the straight and square edges. When you finish this round header don't install it right away. Turn it upside down and take a 3 1/2" strip of 1/2, or 1/4 (but why spend $14.00 for a 3 1/2" of drywall) and after wetting it on both sides slowly and I mean slowly let it drape itself into the mold you have made. You might have to wet it twice or three times or put a LITTLE weight on it to conform to the mold. Mr. gravity will help you in this endeavor, as opposed to nailing the plywood in place on the wall and trying to get wet drywall to stick over your head. Install the finished header with the drywall in place, come back with your 1/2" drywall on one side, trim to the curve and rock the other side and trim. It's better if your joints are a stud away from the opening rather than at the jack stud, or the immediate king stud

Personally I would get out my trammel points: these are devices that make any 3/4 x 3/4 stick of wood into a giant compass and have clamps on them and a place to put a pencil, or just get a straight piece of 3/4" stock and drive a nail in one end and a hole in the other end that would accommodate a #2 pencil, or just the point and secure it with tape at the radius you would like the arch to be, lets say 4'-0"=48". Assuming your arch is going in a non bearing wall, you will need to open the wall up to 52". Why 52 you ask? well you will have to add one jack stud to either side of your opening, that equals 3" and if you use 1/2" drywall that equals 1" on both sides, and that is 4" plus 48" equals 52". You might have to add additional king studs after you open the wall because even though the studs may be centered on 16" that will only give you 48" on center, and if you're demo-ing a door you will have to remove the existing jack, king studs and header.

Find some new header material that will handle your 49" radius, 2x10, 2x12, or plywood laminated to equal 3 1/2" to equal the width of the existing framing, you can rip a 2x4 to make 2 1/2' spacers plus 1" of plywood equals 3 1/2 wall. Why 49", because the 1/2" drywall x 2 equals 1" - equals 48", at the sides anyway. Take your trammel points, or your straight stock with pencil and measure 49" between the two and make your radius mark. Make sure you have enough plywood on top of your arch so that it matches any height openings in the room. The gross length of the plywood will be 51" so that the plywood and 2x44 template will sit on the jack studs. screw the 2 pieces of ply together and cut out with your jig saw, Sabre saw or saws all. Lay out the spacers on 16" centers and screw them to one piece of plywood. Flip the plywood over and screw it to the spacers making sure you line up all the straight and square edges. When you finish this round header don't install it right away. Turn it upside down and take a 3 1/2" strip of 1/2, or 1/4 (but why spend $14.00 for a 3 1/2" of drywall) and after wetting it on both sides slowly and I mean slowly let it drape itself into the mold you have made. You might have to wet it twice or three times or put a LITTLE weight on it to conform to the mold. Mr. gravity will help you in this endeavor, as opposed to nailing the plywood in place on the wall and trying to get wet drywall to stick over your head. Install the finished header with the drywall in place, come back with your 1/2" drywall on one side, trim to the curve and rock the other side and trim. It's better if your joints are a stud away from the opening rather than at the jack stud, or the immediate king stud

I have done this a few times. If the steel studs are in a good position, I use 1" drill tipped screws into the stud, OR I put 6 E-Z Ancor's into the wallboard next to the stud. I have hung up to 120 pounds on 4 E-Z Ancor's and never had one come out. -Available in Rona and Home Depot.

Assuming the following:

2" wide tape

4 coats of compound: 1 base (tape adhesion) layer and 3 finish layers with each roughly the same amount or mud but spread over a progressively wider area

For area calculation purposes each layer has a center thickness of about 1/32" tapering to zero over 2" (1" of tape plus 1" feather per sheet of gyp) or the equivalent spread over a larger area.

Doing the math (might want to check it!):

You will need 6.5 to 7 gallons of compound.

If you have three layers total:

0.703 cu. ft. with (.133 cu. ft. = 1 US gallon) = 5.25 Gallons. Mathematically, you would round down, but tectonically, it's probably better to round up to six gallons...You know, in case someone trips over the bucket....or screws up the math! Good Luck.

Wet sandpaper is used by briefly soaking or wetting the paper with water and then sliding it back and forth across the surface. Water helps to clear away dust and debris which would otherwise clog the paper.

If the framing is wood, you use the #6 x 1-1/8 drywall screw. If the framing is metal, you can still use those screws, but I find it goes faster if I use #4 x 1 inch drill tippedscrews. About 50% more to buy (at Drywall warehouses) but they save lots of time.

You don't have to , buti f it makes you feel more secure go ahead, it won't hurt.

It's drywall that is installed in bathrooms and kitchens. It comes in green and blue depending on the manufacturer. It is moister and sometimes mold resistant. It is still dry wall though and will degrade quickly if excess moister comes in contact with it.

What really protects drywall is the primer and paint that cover it.

You have to be able to lift heavy stuff, often in awkward places, have a good sense of 'square' and not too much imagination or the boredom of it will make you crazy.

It would depend on the type of ceiling that is being installed. Ask a more specific question, like "How do you install a suspended ceiling?", or "How do you install a drywall ceiling in a basement?"...something along those lines.