Thanks again again guys, but, most respectfully, you are not giving the required consideration due to this peculiar work area. Normally, (as I've done a 100 times before)I would get out my trusty acetylene torch and fabricate copper all the way, but,(sorry to repeat again) I'm working in a very small cavity between aged 8"x8" beams and 2"x10" joyce grids and hate the idea of an open flame in this area regardless of cautious efforts. I presume the plumbing network was installed before they closed in the plaster & lath ceiling of the dinning room below.. Any thoughts on good old brass compression fittings being closed in? In case your wondering, getting at the traps in the future's not a problem as access to both can be accomplished through the ceiling in a closet.
Thanks again,your points are well taken and certainly absorbed. In the meantime I'm going to bed with the happy thought that you guys will bless my idea Re. Compression fittings... Thanks again... CORNEY

Hi Corney...

Sorry, but compression fittings are an even worse idea than the sharkbites in a concealed area.

In my area, sharkbite fittings are still not allowed in concealed areas, but I hear they will be soon. Compression fittings are NEVER approved for use in concealed areas.

Either hire a plumber to solder on some transition fittings like I mentioned in your last post or, if you must, install the sharkbites (as mygirl'sdad77 said,they are approved for this purpose in many states)... anything is better than compression, OK?

Good day!

In addition to Mark's advice: Take a spray bottle and generously spray cavity in and around the work area. Get small tip torch to give you better control of the flame. Also, it is a good idea to use heat shield pads. By the time the surrounding wood starts getting hot, the fitting should be soldered. When finished, spray entire area with water again. Don't cover up cavity right away. Leave it open for day or two. Hope that helps. Back to you. Milo

Hello again guys.I know I'm starting to kick a dead horse, BUT, once again I say with GREAT RESPECT, I think either some of you didn't read my whole question or didn't grasp my basic trepidation Re.soldering in a precarious area.
I have a great little acetylene unit complete with a 6ft,hose and interchangeable tips which is really great in tight spots and I have no problem sweating fittings.
My major problem in this case was due to the age and dryness and the proximity of the woodwork in this area the possibility that should I experience a flare-up and have to apply water, I would not be able to control any run-off thus causing damage to the plaster-lath ceiling immediately below the work area. So in essence, it was never any lack of confidence in my "sweating" ability that led me to think of "shark-bites" or even compression fittings. I just wanted to clarify my situation for those of you who advised such solutions as spraying the area with water, or hiring a plumber, or creating an access door, etc.etc.

I'd really like to emphasize my sincere appreciation to all you guys that took the time to answer and in future, when I get a little more familiar with navigating around this great site I'll try to learn how to include "pic" with my inquiry... Thanks again guys... stay safe and well... CORNEY