How Much Weight Can A Bonus Room Support? (Can It Be A Home Gym?)

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If you purchase (or build) a home with a bonus room in it, your imagination might be running wild. You are probably thinking about everything you can do with your bonus room, and this could include building a home gym upstairs.

At the same time, before you start rapidly buying furniture and equipment for the home gym, make sure it can support the stuff you buy. So just how much weight can your bonus room support?

The good news is that your bonus room can probably support just about everything you put up there, but it is critical to be on the safe side. After all, the consequences can be severe.

If your treadmill is 300 pounds and you get on top of it, you certainly don’t want to go crashing through the floor. What do you need to know?

The Typical Load Limit for a Bonus Room

A treadmill and handheld gym equipment on a room with some mirrors on the far wall
A treadmill and handheld gym equipment on a room with some mirrors on the far wall

This is often pretty self-explanatory.

What you need to know is that the load capacity for the second floor of a home, including the bonus room, is usually about 30 to 40 pounds per square foot. These are international regulations, and they should be the same just about everywhere you go.

(Although if you’ve got time for a quick journey back in time, a US government report dating back to 1925 agreed that 30-40 pounds per square foot is ideal – so this is a time-tested rule, too!).

If you have an older home, or if you think your home was built with inexpensive materials, it might be on the lower side; however, the limit of a bedroom is typically closer to 30 pounds while the limit for a bonus room (or other room) is closer to 40 pounds. So, there there are a few caveats you need to know.

First, this does not mean that if you put 45 pounds on a single spot in your bonus room, it will immediately tumble to the floor below. So, you can put the image of yourself plummeting down into the garage (or whatever room is under your bonus room) out of your mind. What this means is that you need to take the total square footage of the room and compare it to the total load limit to figure out if you are over the recommended amount.

Here is an example calculation. If your bonus room is 15 x 15 square feet, this means that it is 225 square feet. If you are calculating the limit for a non-bedroom, such as a bonus room, use 40 square feet as the number. If you multiply 40 by 225, you get 9000 total pounds. This is obviously quite a bit of weight for a room that is 15 x 15 feet in size.

What The Numbers Mean

Cool, so you have the limit. Now, what does this mean? What it does NOT mean is that if you put 9,001 pounds in the room, everything will immediately fall to the floor. There are legal reasons (and moral reasons) why these numbers come with some leeway. At the same time, follow the guidelines. Don’t risk it.

On the other hand, don’t take all of that weight and drop it square in the middle of the room. Almost assuredly, you will have major problems, even if the floor doesn’t immediately fall away, which it probably will if you put all of that weight in the middle of the room in one spot.

To be on the safe side, you need to distribute all of that weight across the floor as evenly as possible. What does this mean, and how should you set up your bonus room?

Setting Up Your Home Gym

Various gym equipment on a room with an in built shower
Various gym equipment on a room with an in built shower

Now, if you want to set up your home gym, there are a few general tips you should follow. They include:

  • Get rid of any extra carpet and padding. This weighs a lot, and it could end up putting you close to the weight limit. Besides, carpet is probably not the best flooring for your home gym. You will probably sweat on top of it, and this will only lead to odd odors that you want to get rid of.
  • If you have tile in your bonus room, get rid of it. You are going to put heavy home gym equipment on top of it, and the home gym equipment will probably crack the tile. Don’t let this happen.
  • Try to place some plywood on top of the floor. Plywood is cheap and it will distribute the weight of the equipment more evenly across the floor. This is critical for preventing the buildup of weight in one place. In addition, you will protect your valuable floors from damage.
  • Then, you can put lightweight rubber flooring to further distribute the weight. Rubber flooring designed specifically for gyms is light, so it shouldn’t add much to the total. In addition, it is critical for reducing the noise coming from the gym.

Once this is done, there are a few general tips to follow for placing your equipment. They include:

  • Put the heavier items up against the walls. This might even place the equipment close to a load-bearing wall, which gives you a bit of extra support. If you are curious about whether the wall is a load-bearing wall, you might want to reach out to a contractor or consult your homeowners’ documents.
  • In general, you should keep your equipment out of the center of the room if you can. This tends to be the weakest point of the room because it is the furthest away from the walls.
  • Try to figure out where the joists are underneath the floor. Then, try to place your heavier equipment in such a way that it goes across multiple joists. This is a great way to distribute the load throughout the room more evenly. You should also try to place the equipment close to the ends of the joists, as these are the strongest parts.

Of course, you need to figure out which pieces of equipment are the heaviest and which are the lightest. You can take a look at the packaging to figure this out, but there are a few general rules. Your dumbbell racks, your squat rack, and your treadmills are generally your heaviest pieces of equipment. This will help you place the items in the right spots.

What Happens If You Are Over the Limit?

If you end up going over the limit, you might start to have visions of yourself plummeting through the floor once again, crashing into your dining room table. Again, this is, more than likely, never going to happen. Instead, you are going to notice structural integrity issues start to develop with your bonus room. There are a few ways this might develop. They include:

  • Your windows might start to look crooked. If you stand in the middle of the room, the windows might look like a painting that is a bit askew. You might have to tilt your head to get the window straight, which is a sure sign of a problem. Then, if you open the window, you might not be able to get it to close again.
  • The same thing could start to happen to your doors. If your door appears to have an uneven gap underneath it, this is a sign that there is structural damage to the room.
  • Furthermore, you might notice that the floor itself starts to buckle and sag in certain spots. If you feel yourself losing your footing as you go across the room, this is a sign that the floor is starting to buckle.
  • You might even notice that your floorboards are punctured. This usually happens because people drop the weights in certain spots, damaging the floor. Don’t let this happen. This is why you need to put down added padding.

These are just a few of the biggest issues related to structural integrity that you might notice. If you want to avoid these problems, you need to think carefully about where you put your items.

What About Other Types of Rooms?

A bonus room with a pool table in it
A bonus room with a pool table in it

Of course, there are plenty of other potential uses for your bonus room as well. A few general points to keep in mind include:

  • If you use your bonus room as a game room, you shouldn’t worry about TVs and video game systems weighing too much. Your couch should be fine as well. Just make sure you hang the TV well on the wall (i.e. using the right fixings – such as only using drywall fixings if it’s drywall). You do not want the TV to fall off the wall and break itself or crack the floor.
  • If you use the room as a place to play pool or table tennis (ping pong), the tables are very heavy. Fortunately, they are also very large, which means that the weight is spread out across a large area. This should be fine.
  • If you decide to use the bonus room as a home theater, think carefully about where you put the speakers. If they sit on the floor, they will be heavy, so put them close to the wall. This will probably be better for the acoustics of the room anyway. The screen will probably hang from the ceiling or be mounted to the wall, so make sure it is structurally sound.

In the end, the most important point to keep in mind is that you need to distribute the weight well. It is highly unlikely that you will go over the limit of the room. Just make sure to put the heaviest items close to the walls and avoid clustering the weight in one spot, particularly in the middle of the room.

Frequently Asked Questions About Bonus Rooms and Weight Limits

There are a few common questions people have about bonus rooms and weight limits. They include:

What is the math I need to do to calculate the weight limit?

If your bonus room is not a bedroom, the weight limit is probably 40 pounds per square foot. Multiply this by the square footage to get the approximate weight limit your bonus room can support. If you have questions, you should reach out to a contractor, ideally the team that built your house.

Why is my floor creaking?

If you notice that your floor is creaking, you might be concerned that the floor is buckling. This does not necessarily mean that there is structural damage. The most common cause of this is changes in the humidity level of the room. When the humidity changes, the floorboards can expand and contract. This can cause a creaking noise, particularly if the nails begin to loosen.

What are the heaviest items most people put in their bonus rooms?

There are a few items that could be particularly heavy. Most of the heavy equipment comes from a home gym, with a few examples being the treadmill, the weight rack, and the squat rack. Make sure to put the heaviest items far away from each other. Ideally, place them on top of a load-bearing wall to make sure they have the right level of support.

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About Charlie D Paige

Charlie is a massive DIY fan, with dozens of DIY projects under his belt - ranging from tiling to electrics, and concrete pads to walls. Charlie loves tinkering, seeing how things works, the outdoors and playing with power tools... so is it any wonder that he's completed so many DIY jobs over the years?

Charlie loves spreading his hard-won DIY experience with the world via this blog.