Prior to caulking the lead joint I use a level then pour the joint and tap each side of the lead so the drain does not shift then finish packing the lead and trim the lead with a trimming iron...same as for CI roof drains except roof drains are slightly counter sunk to allow for the 4 PSF sheet lead flashing
The difference between a gully trap drain and a floor drain is placement. A floor drain is in a floor, a gully trap drain goes on an external wall.
There should be a drain valve on the boiler. Drain it to the desired water level there.
A floor drain , drains water and other liquids that spilled on the floor
I have had it like that at a house I lived at, it would drain directly into the basement floor drain, however it was a pain in the behind, because I often found myself tripping over it, or if the kiddos wanted to ride their bikes or 3 wheeler toddler things in the basement they would get hooked up on the hose also. And if it got to far away from the floor drain I had a water mess, so if at all possible go with the drain behind washer, out of sight ... out of mind.
Floor drain trap can dry out leaving no seal, allowing sewer gases to escape.
Floor is sloped toward floor drain for draining. Floor cleanout is level with floor and is used to clean out drain line.
The toilet flange is usually above the floor level. You would have to cut it off the drain pipe and cap it. How you do this depends on what type of pipe the drain is made of. Even if the drain should be below the floor level, you have to seal the drain or sewer gas will come up from the drain.
Leak on drain line above floor level
The difference between a gully trap drain and a floor drain is placement. A floor drain is in a floor, a gully trap drain goes on an external wall.
No.
There should be a drain valve on the boiler. Drain it to the desired water level there.
I'm not sure what you are asking. Water connected by any means will always seek it's own level. In a sump pump, either the floor is sloped towards the drain or if it has a perimeter drain, pipe under the floor, it will be sloped towards the drain and gravity takes it there.
A floor drain , drains water and other liquids that spilled on the floor
The drain from the washer to the main line is getting plugged and the floor drain is easier. Drain cleaner in the floor drain should take care of it.
That would make for an awfully low toilet.
Not much other than the floor slopes into a flor drain so any water or other fluid goes directly into it while a floor sink is bigger, sometimes has a strainer in it but pipes can be ended directly above floor sinks so that the fluid from the pipe flows pirectly into it
You would have to build a platform for the tub to sit on. About 3 inches if you are using a floor drain. There is a trap right after the floor drain so you would not need one at the tub. If possible you could position the tub directly over the floor drain but that would eliminate the floor drain which would be a problem if the basement every flooded.