First of all, when the enlightend poster above, said roofers dont use glue well he's right and wrong. We use many differnt addhesives but only to secure certain tiles on a tile roof, caulk nails, or to fix some crews jack ass mistakes.lol. well now on too a few ideas ! if you have the money available to get a tile roof then take your knock and learn from it ie. (when getting a roof installed you can pay for an inspector to inspect the roof at specific intervals or after installation is complete,or go down and get a list of building codes specific to your roof have at time bid and insist they be follwed ohh and watch at least 30-45% of work maybe even ask to see the condition of you sheeting).ok now if you dont want to buy a whole roof and they cant help you fix it right. ashpualt shingles can be tared,mastiked,caulked lol "glued" but that wont fix potential leaks .I would use roofing cement a 3 gal can,one caulking gun w/ three tubes of the same cement, a 5 gal tank of propane w/ good torch,go to the attic if you have one,simply look for wet or water staind sheeting if you have any drive a 2 to 3 inch nail at highest wet point, anywhere but next to chimnies,skylights, and long stretches or of wall to roof flashings flashing areas need to be inspected from the roof lol most crews that lack proper ethic would LOL "glue" hear so look for that as well. now the spots where you may have nailed up through the sheeting and underlayment need to be inspected and replaced.from the nail up at least 2ft needs to be replaced i would go higher and at least one shingle width in each direction.note shingles installed in winter or cold/windy conditions should have at least five nails driven flush not high or sunken/overdriven And the shingles come with there own glue opps i mean tar on them so if it is cold and high wind any new unheated/ shingle will simply blow off lol . now dont mess with any flasings at all 97' is getting old professional help is needed cement every thing that isnt staying down.then take your torch and use at full throttle be carefull start on any dormers/or main valleys and heat the shingles 1or2 at a time just until they steam take your foot ,the backside of a hoe whatever you can coneup with to compress the shingles at the nail line even if they didnt nail there lol. these efforts may be fruitfall.I personally could fix just about any leak with henrys 208 alone, but I preffer not to. good luck