i have been chaseing a leak for twenty years. help.

on and off for twenty years i have had a leak in my roof. the roof has been replaced twice. i now have more tar and flashing then shingles. the leak gets worse. i cut holes in my sheetrock so i could find the leak. it comes right through the sheathing like there was no roofing.

it leaks where a one story addition joins a two story house. the addition has an almost flat roof. the other roof is pitched.

lets assume the worst. the house was built wrong. the flat roof goes uphill, the water can not easliy drain. if you were hired to roof such a house, what would you do?

or, lets look at it another way. if a section of roof leaks even after you repaired it, what would you use to make sure it would never leak again?

what causes water to go through tar and flashing ? or , at least , get under tar and flashing ?

 

Only two ways for water to get under tar and flashing...from above or below (from a flat roof).
I would re-tar a bed of plastic roofing cement the width of the flashing under it where those two roofs meet, and make sure that everything above and below it were tarred to the top of the flashing.
Good Luck!
Mike