If your roof was laid in 1989 it is most probably white chrisotile fibre. I cant remember exactly if this does contain asbestos. I dont think it does. Ask your local environmental health agency who could probably suggest your next step. Removal of asbestos materials is now very costly as it is hard to find anyone with a landfill site allowed to do it. You can look at another option of over roofing your garage with profiled metal sheeting. That would be a cost saving to you. Good luck. J T
Jim T
July 2011