Joists can be secured in two ways, by having them rested onto beams or by using joist hangers to attach them to the sides of a beam. Both these methods are used to secure joists. Using joist hangers is more expensive but is safer in the long run.
It is important to ensure that all structural members in a floor frame are properly placed and are dissipating loads correctly.
This article compares the two methods of securing joists: using a joist hanger and letting the joist rest on the beam.
What are Joist Hangers?
Joist hangers are support structures used in construction processes.
They are designed to hang wooden joists and beams onto other structures.
Joists hangers are used primarily underneath floors and ceilings for attaching joists with beams creating a long-lasting connection between them.
Over time, joists made from wood may experience twisting and warping if rested on top of beams.
Proper installation of joist hangers helps maintain the integrity of wood joists.
Joist hangers hold the joist securely in place so it cannot be accidentally deformed.
This ensures the longer-term durability and rigidity of joists.
Joist hangers are usually installed over the sides and edges of a beam or under them and are fixed in place using nails.
The hanger comes with a connecting plate that is attached to the beam with nails.
These plates create a rigid connection between the beam and the hanger.
Connection plates can also be used to weld joist hangers.
The plates make joist hangers much more versatile and stronger than normal nails and screws.
Joist Hangers vs Resting on Beam
As a builder, it is important to know where to rest the joists in your frame before starting construction.
Selecting the ideal place and method for resting joists depends on many factors, such as available vertical space, budget, etc.
During construction, joists can be secured in two different ways.
One is to have them directly rest on top or the side of the beams.
This requires the beams to be exceptionally strong to provide adequate support to the joists.
On the other hand, joists can also be hung onto the sides of beams using joist hangers.
Using joist hangers also requires beams to be adequately reinforced.
Which Method Performs Better?
Resting joists on beams is the superior method of securing joists as this direct contact provides more tensile resistance.
It is also quite easy to install joists directly onto the beam, but it may lead to height-related issues.
This is when joist hangers become the better option.
Using joist hangers reduces the overall height alignment issues in a frame and makes the frame look aesthetically more pleasant.
Overall, both methods are valid for securing joists.
The primary reason for selecting one over the other is vertical clearance.
Which Method is Safer During Construction?
Joist hangers are safer when properly installed.
The screws and nails have a fixed place which helps secure joists with the beams.
On the other hand, resting joists on beams requires more nails and can cause deformations in the beam.
The joists need to be blocked using a rim joist, or they can cause the beam to crack by twisting and warping.
Which Method is Cheaper?
Joist hangers add extra costs to the overall project while resting joists on beams requires no additional expenses.
For example, the average cost of a 2x6 joist hanger is between $10 and $20.
Each joist hanger adds more to the total expense.
Thus, resting joists on beams is cheaper than hanging joists using joist hangers.
Joist Hanger Applications
Joist hangers help attach wooden joists onto wooden beams. They also help attach wooden joists onto masonry walls and posts.
Joist hangers can be fastened with nails, screws, or even welded.
They are inexpensive and simple to install.
Types of Joist Hangers
Joist hangers are classified into several types based on their intended use.
The following are some common types of joist hangers.
Standard Jiffy Hanger
This joist hanger is commonly used to support lighter loads, such as flat ceiling joists and light floor joists.
Long-Leg Jiffy Hanger
This joist hanger is designed to carry heavy loads.
They are used to connect heavy joists and beams to other pieces of wood.
Common sizes include 450mm and 600mm.
Long-leg jiffy hangers are extensively used under large floors.
Masonry hangers are used to connect timber joists, masonry beams, and walls.
Universal Joist Hangers
This hanger is the most versatile out of all the other types and can be used for making any connection between joists and beams.
It can function as a replacement for all other joist hangers.
Load Transfer Mechanism
In a floor frame, beams are primary support, whereas joists provide secondary support.
The joists carry the load from the floors and transfer it directly to the beams.
If joist hangers are involved, then joists transfer the load to the beam via joist hangers.
Beams then transfer the load to the columns, which pass it down to the foundations.
Are Joist Hangers Strong Enough to Support Joist Loads?
A common query related to joist hangers is whether they are strong enough to support the loads acting on them.
The reason behind this is their small appearance which can sometimes be misleading.
Joist hangers are very safe if they are installed properly.
They are usually required when the alignment of the joist top must be in line with the beam head.
There are a lot of scenarios where such a condition becomes necessary.
To install joists properly, it is highly recommended to use the installation guides that come with them.
Information regarding the installation process of joist hangers is also available on many steel structures and manufacturer websites.
How Do You Properly Install Joist Hangers?
The most efficient method of attaching joist hangers onto beams is using screws or bolts.
Structural nails are available for joist hangers, but screws and bolts provide much better fastening.
An impact driver tool can be used to drill the screws, but care must be taken not to overtighten the screws, as this can cause cracks in the wood.
Modern lumber structures contain a high copper content.
This copper content, when wet, corrodes galvanized metal hangers.
It is critical to use the appropriate type of joist hanger and fasteners.
Both should have high outdoor ratings.
It is also critical that the beam sizing be done correctly.
Certified and registered structural engineers should only do beam sizing.
This is because beam sizing is a complex matter involving the analysis of various loads.
The material used for the beam has a significant impact on its overall size.
Common Joist Hanger Installation Errors to Avoid
When installing joist hangers, mistakes are common, putting the structural integrity of the entire floor system at risk.
The installation process must adhere to building codes.
Some common mistakes to avoid while installing joist hangers are discussed below.
- Joist hanger sizes are frequently miscalculated, either oversized or undersized.
- The amount of joist hangers installed is insufficient.
- The nailing is not done properly.
- The type of nails used is not correct.
Follow the steps below to avoid inconsistencies in the installation of joist hangers.
- Use the proper fastener size and type.
- Do not leave any holes in the connecting plate of the joist hangers empty.
- Always nail at 45 degrees to avoid hitting the end grains.
- Use of hot-dipped galvanized steel nails for exterior use.
- Never reuse joist hangers as the holes on the connecting plate might have loosened from the long-term initial use.
- Do not cut the joist hangers yourself to modify them.
- The height of the hanger should be at least 60% of the height of the joists.
In a floor frame system, joists can be secured in two ways.
One option is to have the joists directly rest on top beams.
This method is cheap and quite effective, but it leads to height and alignment problems within the frame.
The other method is to hang joists onto beams with joist hangers.
Joist hangers have connecting plates that are nailed to the sides of the beams.
They provide an excellent grip for holding joists in place and prevent them from undergoing twisting or warping.
Overall, the use of joist hangers bears more expenses.
Each joist hanger and its relevant fasteners cost extra.
The decision to choose joist hangers over having joists rested onto beams is typically made when the vertical alignment must be kept in check.
Frequently Asked Questions (FAQ)
How Much do Joist Hangers Cost?
Joist hangers are available in a variety of shapes and sizes, each with its own price.
The average cost of 2x6 joist hangers ranges from $10-$20.
Joist hangers also come in bundles which can prove more cost-effective.
A 100-piece box is available for around $100.
Should Joist Hangers be Screwed or Nailed?
Always use screws to fasten the connecting plates of the joist hangers onto the beams.
Even though there are nails specifically designed for joist hangers, screws still provide a much better hold overall.
Make sure that none of the holes in the connection plate are open.
What is the Most Common Joist Hanger Installation Mistake?
The most common mistake when installing joist hangers is the incorrect use of fasteners.
Screws should be preferred over nails when fastening the connecting plates of joist hangers onto beams.
Another common mistake is not filling all the holes of the connecting plate with a fastener.
This leads to a reduction in the bearing efficiency of the plate.
Another major mistake to avoid is the reusing of joist hangers.
Upon removal of joist hangers, their capacity is lost.