Tapping Your Garage's Hidden Storage Space

Q: DEAR TIM: I think overhead garage storage is the answer to my clutter problem. There is a giant empty space over the hood of both cars in our wide garage. I need a do-it-yourself garage-storage system that will support furniture, boxes and other household items. How would you support a platform like this without any poles or columns that otherwise would get in the way of the cars? Is a project such as this safe?

-- Bill M., Drexel Hill, Pa.

A: DEAR BILL: There are many garage storage systems on the market. Some use pulleys, ropes, cables, hydraulics and so forth to take advantage of the space you describe.

Two years ago, I had the same problem. We moved my daughter back from college with all of the stuff she had in a one-bedroom apartment. My outdoor shed had no room, and my attic was full. We decided to price an off-site storage facility, and the annual cost for the space was more than $1,000.

As I drove home in shock from the storage facility, I thought about my garage and came to the same conclusion you did: the space above the hoods of the cars was enormous. I could easily fit a platform 16 feet long and 6 feet deep, with a vertical space of 45 inches. The best part was that, thanks to the height of my garage ceiling, the platform would still be 81 inches off the floor. That is plenty of room to walk beneath the platform without ducking.

The most important aspect of my overhead garage storage platform was the suspension system I designed. The platform itself was made from 2-by-6 lumber and half-inch-thick plywood. I spaced the 2-by-6s 16 inches on center so the platform would be sturdy.

This platform is suspended from the ceiling with slotted steel corner irons. This simple hardware item is commonly used to hang garage door tracks and openers from garage ceilings. There is not one pole or column that holds up my overhead platform, although I did use several as temporary supports as the platform was being constructed.

To eliminate sway, I attached one end of the overhead platform to a wall by screwing one end joist to the wall studs. This simple connection made the platform rock-solid.

The connection of the slotted steel irons to the roof structure was done with through bolts, not lag bolts. Furthermore, I made the connection high up on the slanted roof rafters, not the horizontal bottom chord of the roof trusses. The sloped parts of the rafters are in compression, while the flat bottom chord is in tension. My engineer friends told me that it was a bad idea to add loads directly to that bottom framing member but that adding the load to the sloped rafters was like adding weight from shingles or snow above, which the roof can hold.

I calculated that the weight of the platform plus the weight of the items being stored would be less than 1,500 pounds. That is less than the weight of an extra layer of shingles on my garage roof. Because my trusses are approved for the weight of three layers of shingles plus any snow load, and I have only one layer of shingles on my roof, I feel very comfortable that my platform will not cause the garage roof to fail.

I highly recommend that you consult a residential structural engineer before you build an overhead garage storage platform. The engineer will check your garage and draw a simple plan showing you the parts you need, including how many slotted steel irons are required. The cost of the consultation will probably be less than two months' rent at a storage facility. It is the best money you will spend on this project.

Tim Carter can be contacted via his Web site, http://www.askthebuilder.com/printer_Submit_Question.shtml.

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