With our new build not having as much storage as our old house, we have gotten creative with where to stash things to keep the house and the garage decluttered. From adding additional shelving in the garage to purchasing cabinet units to store tools, to a tool chest, we are now boldly going where… ok we are installing overhead storage to free up some floor space. When I was surveying what we would be storing overhead, the question popped in my mind. How much weight can a garage ceiling hold? And how can I safely work within those limits to accomplish my storage goals?
The weight that your ceiling can support will greatly depend on the structure of the roof. The most common types are gable, reverse gable, or hip roofs. In most cases, trusses are made from 2×4 dimensional lumber and the weight that the chord (ceiling) can support is 10-12 lbs. per square foot. If the ceiling of the garage is supporting a second story living space, the floor joists can support 40-50 lbs. per square foot. The numbers here are very different depending on how your house is built. Here is how you can get the most out of your garage ceiling, and your overhead storage, while working within the limits of what our garage ceiling can support.
I am sure you are like me when it comes to a new project. When I was looking at different overhead storage options, I was looking at the specs. Size, features, capacity, addons, etc. were all just numbers on the screen. I wanted to make sure the overhead storage unit I purchased was able to handle 600 lbs. and was the largest size and had the additional hanger hooks. The options were endless, and I was lost in the feature dump of the internet. When I came back to my senses from the self-induced vertigo session that I found myself in. I grabbed my measuring tape and a piece of paper and went out to the garage to determine what I needed and what would work best in my space rather than being sold on the spare bike hook that converts into a disco ball that has a mounted rear camera on the north-facing side.
When I got to the garage and started mapping out the space of my garage ceiling, it started becoming more evident what would work for me and what would be best overhead. In my case, I had several things in the garage that I had to contend with. These things included, but were not limited to, the tankless water heater, the garage door opened and track, the whole house vacuum, the oversized side entry, and interior doors, and the attic access. This was sobering for a person who likes to purchase gadgets just because of, well, gadgetry.
Measuring my garage ceiling and having those numbers really helped me determine how much of my garage ceiling was useable and able to hold. By being strategic for how I used the ceiling, I was able to maximize space and functionality. The build features discussed below are what you need to consider when you are trying to determine how much your garage ceiling can hold. There are tricks you can utilize if your storage goal involves heavy things, so you can be able to safely disperse the weight. The most important trick here being location. Let’s get started.
How was Your Garage Ceiling Built?
One of the most important, and the first things that need to be determined when it comes to how much your garage ceiling can support, is how it is built. This might require you to brave seldom charted space known as your attic to gander at the structure and how your garage ceiling was built. This can help determine how much weight your garage ceiling can support.
Here are a few common scenarios to help with your discovery.
Ceiling Trusses and Rafters
If your garage is a single story and has a pitched roof, you are more than likely in a situation where trusses were used to support your garage roof. If you have a newer flat roof, you are still more than likely using a roofing truss, but for this discussion, consider it more like a floor truss which will be discussed below.
In roughly 80% of newer construction, this is the case, but it is still good to determine what you are working with. This could greatly impact how much weight your garage ceiling can support. Trusses can be easily identified because of their triangular formations in each truss which help distribute the weight and provides the truss with its strength. In newer construction trusses are often used since they can be constructed offsite, require less material, and can be installed with a smaller crew. They have many benefits but trusses do reduce the weight the chord (bottom board of the truss), your garage ceiling, can hold.
Rafters are not as common as trusses are in newer builds. This roof structure requires more material, normally a larger crew to install, and needs to be built on-site. Because of that, you are less likely to have this build option supporting your garage. Pity, this is the structure that can support more weight in your garage ceiling. Nevertheless, here is how you can identify if your garage is using rafters and joists to support the ceiling.
When you get up in the attic, take a look at the bottom boards. If they are 2×8, 2×10, 2×12, or something larger, your garage roof is held up by rafters. Those rafters, since there is not the webbed, triangular structure like trusses, require a large bottom board, the joist, to help support the weight of the garage roof. These dimensional pieces will allow your garage ceiling to support more weight, so you will be able to store more than you could if the garage with built with trusses in the attic.
Floor trusses have two parallel dimensional boards that run parallel with the floor. Like the ceiling trusses, floor trusses with have triangular shapes, but more dimensional lumber running at determined angles between the two parallel boards. There is generally more material than in a ceiling truss since the floor truss is meant to support more weight. Flat roof trusses look similar since the same general concept applies and the flat roof truss as does floor trusses. Again, the benefits of trusses are that they can be manufactured off-site, use less material, and require a smaller crew to install.
If your garage ceiling is supporting a second level, and you see single pieces of dimensional lumber, you have a joist separating the levels supporting the garage ceiling and the second story floor. You might see different sizes of dimensional lumber; these are generally determined by the span these joists need to travel. As mentioned with the floor truss, having the ceiling built with a joist and a second story floor above, these structures will make it possible for your garage ceiling to support a heavier load.
What Size Lumber was Used?
When determining how much your garage ceiling can hold, it greatly depends on how the overhead ceiling was built. Determine if your structure has a truss or a joint, and also what size of dimensional lumber was used for the build.
In most cases, trusses are built from 2×4. The truss might also have a 2×6 bottom piece (chord). It depends on the expected load and the distance the truss must span. Everything that I have read stated that having a 2×6 chord rather than just a 2×4, makes it possible to suspend more weight and thus increase your garage storage capacity.
With joists, for the ceiling rafter or an overhead floor joist, you will normally see 2×8, 2×10, 2×12, or multiple boards laminated together. The size and the distance will depend on the distance the board(s) need to span and the expected load that it will be supporting.
So, How Much Can My Garage Ceiling Hold?
First, determine what is already suspended from your garage. If it is finished and has drywall, you need to consider that weight to be about 5-10 lbs. per sq. Ft. Make sure to add that into your equation when you are determining what you are going to store.
Ceiling trusses have a weight capacity around 10-12 lbs. per sq. ft.
For ceiling trusses with a 2×6 chord, the weight capacity is slightly higher, around 12-15 lbs. per sq. ft.
Ceilings built from a ceiling or floor joist are stated to be able to support up to 50 lbs. per sq. ft. But that is a lot of weight. So I would recommend not going over 25-30 lbs. per sq. ft.
If you are looking to store this type of weight overhead, make sure you do not overload your ceiling or the storage system that you purchase.
How to Disperse the Weight
The trusses or joists normally run parallel at 16” or 24” on center apart from each other. Depending on your build, this might not always be the case. But for this example, consider that it is. When looking at overhead storage systems, some of the storage racks might only be intended to be drilled into a single truss. From what I have noticed, and decided with my own garage, there are some overhead storage units that span between two trusses per leg. This will allow for the weight to be dispersed between multiples trusses once it is installed and will allow your ceiling to be able to support more weight since more trusses are sharing the load more evenly.
For further information on overhead storage, check out our article on How to Choose the Best Overhead Garage Storage.