Floor Joist Capacity: Understanding Load Limits

Knowing how much weight your floor joist can hold is essential to prevent your floor from collapsing. But, calculating the floor joist hold capacity can be quite confusing. And especially in most sources, the explanation is quite complex. 

So, to help you understand how much weight a floor joist can hold as easily as possible, we’ll talk about everything related to the topic in today’s article! We’ll also teach you how to calculate the joist hold capacity yourself! So, stick around till the very end! 

How Much Weight Can A Floor Joist Hold? 

Most floor joists can hold around 40 lbs of minimum dead weight per square foot. If you don’t know what dead weight is, it’s the weight of everything that’s not part of the apartment or house.

For example, if your living room were 216 or 12×18 square feet, the floor joist’s minimum dead weight hold capacity would be around 8,640 lbs. To give you a clearer weight list, the average bedroom size in square feet is around 144 or 12×12 square feet. 

And for a room of about 144 square feet, the minimum hold capacity would be around 5,760 lbs. Knowing this is essential to avoid any unwanted damage to your house or apartments! 

How To Calculate Floor Joist Hold Capacity? 

floor joist image

To properly understand how much weight a floor joist can hold, you need to be able to calculate the holding capacity according to the length of your room. And the fun part is, calculating the minimum floor joist hold capacity is super easy. 

All you need to do is find the exact square foot of your house rooms. Then, multiply that by 40 (minimum dead weight per square foot). For example, 216 (12×18 square feet) into 40 lbs would result in about 8,640 lbs. It’s just simple multiplication! 

What Happens If You Place Items Over The Minimum Holding Weight Limit? 

If you place more weight than your floor can hold, it will experience much damage. Usually, it’s not immediate, but the floor starts to break down over time. And right before you know it, the floor collapses! 

This is why it’s important to have proper knowledge and understanding regarding your home. One simple mistake in calculation and you may risk the safety of everyone in your house and people living under you. 

Nowadays, floors collapsing is very rare. But with older homes, the holding capacity isn’t as good, so it’s very important to be careful with those. Especially with wooden floors, it’s essential to know the holding capacity before placing any heavy items on them.  

Why It’s Important To Know How Much Weight Your Floor Joist Can Hold?

Knowing your floor joist’s weight limit is essential to avoid structural disasters. The most common thing that can happen if you’re not careful about the holding weight limit is the floor collapsing. 

This is very common, especially with wooden houses. The floor joists can only hold so much weight on them. If you were to try and place an 80,000-lb garbage truck on a wooden surface that can only hold about 8000 lbs, it’s bound to collapse. 

And you don’t want your house or apartment floor to collapse suddenly. So, to avoid disasters, it’s essential to know how much weight your floor joist can actually hold. 

Signs Your Floor Joist Might Be Collapsing 

floor joist taking weight image

Your floor joist can only hold a certain amount of weight, but your floor joist wouldn’t just collapse out of nowhere. Usually, your floor joist may show a few signs of damage before collapsing. 

So, here are signs your floor joist might be collapsing: 

  • Uneven floors
  • Breakage 
  • Cracks 
  • Leaks 
  • Crackling noise 
  • Floor start to sag 


So, how much weight can a floor joist hold? Well, just about 40 pounds per square foot. Now, to know the exact weight your floor joist can hold, just multiply the square foot by 40! 

Ensure you know your floor joist’s weight limit to avoid disasters. And all you need to do is calculate the limit using the method we taught you! Until next time, Goodbye! 

Frequently Asked Questions 

Q. Can A Floor Collapse From Too Much Weight? 

Ans: Yes, a floor can collapse from too much weight. Every floor has its own weight-hold capacity. And if that were to be exceeded, your floor would be at risk of collapsing. Think of it like this; you can’t place an 80,000 lbs dump truck on a floor that can only about 8,000 pounds and expect it not to break down! 

Q. How Much Weight Can A Typical House Floor Hold? 

Ans: A typical house floor may hold about 7-9,000lbs of weight. This mainly depends on how many square feet the house floor is. But usually, house floors cover about 216 square feet, so the weight capacity would be 8,640 lbs. 

Q. How Much Weight Can A Floor Joist Hold? 

Ans: A floor joist can hold just about 40 lbs per square foot. To calculate the weight, you must multiply the minimum weight per square foot by your floor’s square feet. 

Q. Why Does My Floor Make A Crackling Noise? 

Ans: Your floor might be making a crackling noise for a few different reasons, but a weak floor joist can be one of the main reasons. When floor joists become weak, they show a few signs of damage, including a crackling noise. 

Q. Can You Increase The Floor Joist Length? 

Ans: Yes! You can increase the thickness of floor joists on a floor. But, you need to apply careful planning, and it’s recommended that you get yourself a good house planner to avoid any unwanted damages later on.