You’re on the second walk-through. Someone presses the garage door button, the door goes up, and everyone nods. That tells you the motor runs. It does not tell you whether the springs are worn, whether a cable is frayed, or whether the door will reverse if something is in its path.
Once you close, all of it is yours. You can learn most of what you need with your eyes and a short piece of wood. For the longer version, read the full lab on checking a garage door before you buy.
Test the auto-reverse first
Run the door all the way up and all the way down. Watch it the whole way. It should move steadily and close to the floor without stopping partway.
Then look low on both sides of the opening. The photo eyes sit about 6 inches above the floor. If they are misaligned or blocked, the door will stop short and reverse. Federal rule 16 CFR part 1211 requires residential openers to have a secondary entrapment protection device, and requires the door to reverse within 2 seconds of touching an obstruction.
To test it, lay a 2×4 flat in the door’s path and close the door. It must reverse when it hits the wood. If it does not, stop using the opener. Write it down and bring it to the seller’s agent before you close. If the door stops short on its own, this guide to doors that won’t close covers the usual causes.
Look at the springs from the floor
Find the torsion spring on the bar above the door. Look at it from the ground with a flashlight. Do not touch it.
A healthy spring is wound tight with no gaps. A broken one shows a visible gap in the coils. Orange or flaky coils mean the spring is deteriorating. If you see either, the spring needs a technician. Our partner guide on garage door spring issues explains what each sign means.
A spring that looks fine still has an age. A standard spring is rated for about 10,000 cycles, one cycle is one full open and close, and at four cycles a day that is about seven years. Ask the seller when the springs were last replaced. HomeAdvisor lists spring replacement at $180 to $350, so a spring near the end of its rating is a scheduled expense you can negotiate around.
Run the balance test only with the seller’s okay
The balance test means disconnecting the opener, so ask first. Ask the seller to show you the release and to reconnect it afterward. If you saw a gap in a spring, skip this step entirely.
With the door fully closed, pull the release, lift the door halfway, and let go. A balanced door stays put. A door that slams down or shoots up is out of balance and needs a professional. The balance test walkthrough shows the steps in order. Note what you find. Do not try to correct it.
Cables, tracks and brackets: look, do not touch
Follow the thin steel cables from the bottom corners of the door up toward the spring bar. Frayed cables can break. Stay clear of them.
Look along both tracks for bends or twists. Bent tracks are professional work, and they put extra strain on the opener. Leave the bottom brackets alone. They hold the door under tension, and Clopay warns they must not be removed while it is loaded.
Find out how old the opener and seal are
Genie puts the average opener life at 10 to 15 years. Ask when this one was installed. If it is well into that range, budget for a replacement. HomeAdvisor puts a new opener installation at $218 to $540, with an average of $379. Listen while it runs, too. Chain drives are much louder than other types, which matters if a bedroom shares a wall with the garage.
Then kneel and look at the rubber seal along the bottom of the door. Look for cracked, flattened or missing sections. Clopay says most weather seals need replacing every 2 to 3 years, depending on climate and use. A humid coastal garage, a freeze-thaw garage and a hot-dry desert garage will each wear a seal differently, so ask how long this one has been in place.
When to bring in a professional before closing
Get a professional to look before you close if the reverse test failed, a spring showed a gap or heavy rust, the balance test went wrong, a cable was frayed, or a track was bent. Garage Door Pros has a page for a free garage door safety inspection. If the door passes, the annual tune-up guide and the yearly maintenance guide set up your first year of ownership. For symptoms you can’t place, how to diagnose your garage door before you call a pro narrows it down.
At your next showing, do these in order:
- Run the door up and down, then do the reverse test with a 2×4 laid flat in its path.
- Look at the spring from the ground for gaps or orange, flaky coils.
- Ask the seller three questions: how old are the springs, how old is the opener, and who made the door.
Bring a 2×4 and a flashlight. They will tell you more about that garage than the button ever will. Read the full guide on Garage Door Science.
Frequently Asked Questions
How do I check the garage door before buying a house?
Run the door up and down, then lay a 2×4 flat in its path to test the auto-reverse. Look at the spring from the floor for gaps or orange, flaky coils, and ask the seller how old the springs and opener are. Do not touch the spring, cables or bottom brackets. If anything fails, have a professional look before closing.
How do I test a garage door’s auto-reverse with a 2×4?
Lay a 2×4 flat on the floor in the door’s path and close the door with the opener. The door must reverse when it touches the wood. Federal rule 16 CFR part 1211 requires reversal within 2 seconds of touching an obstruction. If it does not reverse, stop using the opener and have a technician check it.
How long do garage door springs last?
A standard spring is rated for about 10,000 cycles, one cycle is one full open and close, and at four cycles a day that is about seven years. Heavier daily use wears them out sooner. Ask the seller when the springs were last replaced, since HomeAdvisor lists replacement at $180 to $350.
How old is too old for a garage door opener?
Genie says most openers last an average of 10 to 15 years. An opener in that range still works, but budget for a replacement. HomeAdvisor puts a new installation at $218 to $540, with an average of $379. Ask the seller for the install date before you close.
Should I ask the seller to fix a failed garage door before closing?
Yes, if the reverse test failed, a spring has a gap, a cable is frayed or a track is bent. Those are safety items, and a professional should look before the sale is final. Bring the written notes from your walk-through so your agent can raise it with the seller.
