Joists are important in deck building. When building a joist for your wood or composite decking, you should space it properly. If you don’t construct it properly, it could cause the decking to sag. What are decking joists? And how far apart should a decking joist be?

What are Decking Joists?

How far apart should a decking joist be?

Decking joists are long pieces of timbers on which you can lay wood or composite decking. The joist serves as a framework on which to lay your decking. It also serves as a support for the deck, ensuring that the weight of the deck is well distributed. When building a joist for your decking, you should use the best type of wood or treated wood to make it.

 A reason for this is that woods are more prone to damage. Wood can crack or splinter. It can also get rotted or eaten by termites. But if you use the best wood material or treated wood to build your joist, it will extend the lifespan of the wood. Remember that the joist serves as a support for your wood or composite decking, so if it is not strong enough, the deck will collapse. 

However, when building the joist for your decking, you need to install it properly. You should space the joists accurately.  If it is too far apart, it can cause the decking to sag. Apart from that, if its height is not uninformed, it can also cause an uneven deck surface. When you stand on the deck, one part will be higher than the other. 

To prevent that from happening, you need to follow the guidelines on joists spacing. The spacing of the joist should not be too far apart, nor should it be too close. So how far apart should decking joists be?

How Far Apart Should the Decking Joists Be? 

Most decking comes with joist guidelines from the manufacturer. If you want to install decking, to know how far apart the decking joist should be, follow the manufacturer’s guidelines. Some decking manufacturers recommend a maximum spacing of 12 inches on centres, 14 inches on centre and 16 inches on centre.

However, the spacing requirements also depend on whether the decking is for residential or commercial use. 

For residential use with a limited number of people on the decking, the recommended spacing is 16 inches on the centre. But if you want a more rigid feel for your decking, you can choose to space it by 12 inches on the centre. While for commercial use with greater pressure on the decking due to many people, decking experts recommend a spacing of 12 inches on the centre.

Additionally, how far apart a decking joist should be also depends on the angle and length of your deck. Some decking manufacturers recommend 16 inches on the centre for an angle of 90 degrees. And also,14 inches on centre for an angle of 30 degrees and 12 inches for an angle of 45 degrees. Knowing how far your decking joist should be, how can you install the joist properly.

Tips For Properly Installing Joist

Ensure the Deck Frame Is Structurally Sound

First, you should ensure that the joist is structurally sound. To do that, use blocking to support the joist. 

Install Blocking

Blocking increases rigidity and helps to keep the decking joists from sagging. You can install blocking by adding small pieces of wood in between the decking joists. 

 Ensure All Joists Are Equal

You should also ensure that the joists are of the same level. If a part is too high than the others, make it uniform with the other parts by cutting it. Also, if part of the joist is lower than the rest, add shims to make it equal. Ensure that the joists are equal by running strings line across the top of the joist often. 

Make Sure the Joists Are Spaced Correctly

You should ensure that you spaced the joist properly during installation. For residential decking, the spacing should not be above 16 inches on the centre. While for commercial use, experts recommend that you space the joist by 12 inches on the centre.

Cross-Check Your Work

 Finally, you should cross-check your work. Take your time to inspect the joist, check for protruding nails and screws.

Conclusion

How far apart should a decking joist be? For residential decking, the spacing should not go beyond 16 inches on the centre. While for commercial use, experts recommend that you space the joist by 12 inches on the centre.