I am an HVAC installer and have done many change-outs and duct system installs but I don't have a lot of experience fluing woodburning stoves.
My friend has an old stove that he asked me to flue. I took a look at the existing flue and it had ss sand filled metalbestos flue going through the roof which was leaking water through the interior of the pipe.
I checked the storm collar and the under the roof jack and I couldn't see any evidece that the water was getting in there. The vent cap was on properly also. I'm not sure what would cause water to get in except that maybe wind is blowing it under the vent cap and it is leaking down through the pipe.(whoever installed it originally had it tilting at an angle - this could be the problem.)
Also, I'm wondering if I can use double wall flue to vent the stove on the interior of the house up to the ceiling or do I need to use the stainless steel stuff.
If anyone has experience with this can you please give me a little help.
First thing first
You must be sure the existing chimney meets building code. There have been many versions of insulated chimneys, the early ones were prone to failure due to the insulation settling and causing hot spots. You also need to ascertain if the chimney was installed correctly, clearance to combustibles is imperative!
If all is good, you can use a listed double wall pipe to go from the stove to the chimney, look at the back of the stove and make sure you follow it's listed clearances as well.