I am thinking of getting an attic fan or gable vent to cool our attic. We actually have two attics, one above the garage and another above the main house. We have soffit vents, but no way for the air to get out, which is kinda weird to me.
Anyone ever do this or contract this kind of work out?
You need to get power to it unless you do solar fans. Solar fans are very effective but very pricey. We get calls every year around this time to run electricity to power vents (I'm an electrical contractor). The other thing you have to do is cut a hole in your roof to mount it and make sure you replace the shingles properly so you don't have leaks. If you go the gable end route it might be easier.
Screw up either of these and you could burn your house down or develop a roof leak.
Depending on your skill level it could be very easy. If you don't feel confident after looking at it, I wouldn't tackle it. You don't want to cut a hole in your roof and then have to look for a contractor that will come over right away.
If you need help with the electrical PM me, I live in Carmel.
Are you sure you don't have a ridge vent? If you don't have box or gable end vents, ridge vent is the next viable option - and the most efficient of all the passive airflow options.
If you have NO vents at all, your roof will be cooking from the inside out! A 25 year roof could be trashed in 5-7 from that much heat buildup.
Many roofers will advise AGAINST electric attic fans unless you install them along the entire length of the roof. The reason being, an attic that is uniformly 90 degrees in the summer will last longer than a roof that is cool in some spots and overheated in others. An attic fan or power vent will definitely disrupt the airflow from your soffit vents through "whatever" venting system you have - at least while it is running.
I have zero ventilation in my attic. It's insulated on the underside of the roof deck with icynene. It's supposed to make the shingles last longer. I have no insulation on top of my drywall ceilings.