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Basement Beams Guide: How to Replace Them



V Susan
Hi! I'm Susan. I am passionate about woodworking, general DIY and home improvement. If you'd like to connect with me or talk about something you like at mellowpine, drop me a mail at susan@mellowpine.com


Basement Beam in a house (1)

Basement beams are the main load-bearing elements that carry all the loads above and transfer them to the foundation. However, over time these beams may deteriorate, requiring reinforcement and replacement. To replace basement beams, place temporary supports, remove damaged beams, and install new ones.

What are Basement Beams?

Basement beams carry the load from joists above them. This load is quite heavy, and thus removing a basement beam can cause the floor to collapse.

However, over time these beams deteriorate and develop cracks, making it essential to replace or reinforce them.

Basement Beam and Column Post.
Basement Beam and Column.

How to Replace Basement Beams?

Moisture and water leakage tend to worsen the structural integrity of basement beams.

This can happen in areas where there’s a likelihood of flooding, such as walkout basements.

In such instances, it becomes necessary to replace them.

Here are the steps to replace a basement beam:

Step1: Set up Temporary Support

The first step is to identify the beams in your basement.

Most basements are semi-finished or unfinished, which means beams are likely to be exposed and visible.

Otherwise, you’ll need to remove any kind of ceiling that’s covering the beam.

The first step in replacing a basement beam is to set up a temporary support wall to bear the weight of the floor and ensure safety during the work.

Usually, a timber wall is set up on both sides of the basement beam to act as a substitute load-bearing member.

These vertical lumber panels are nailed into the horizontal beams on the top and bottom of the wall.

Temporary Wall Support.
Temporary Wall Support

Step 2: Relocating the Jack Post

When replacing the basement beam and removing the jack posts, it’s essential to choose new support locations.

Reusing the same spots is not advisable as it would have lost its bearing strength.

To ensure stability, excavate the new locations for jack posts and pour concrete to reinforce them.

Step 3: Cut a New Beam for Replacement

Measure the dimensions of the old beam that needs replacement.

Order a new beam and cut it into the required size.

In cases where the old beam may not have provided sufficient support for the floor load, it is advisable to replace wooden beams with steel I-beams.

Step 4: Remove the Old Beam

Remove the jack posts supporting the existing cracked beam and start removing the damaged beam by cutting it into small pieces.

Cutting this way ensures that the temporary support wall is sufficient to hold the weight above.

Cutting of Old Basement Beam.
Cutting of Old Basement Beam.

Step 5: Place the New Beam and Posts

Place the jack posts in their new location and install new beams above the posts.

Secure the beam firmly to the support edges and remove the temporary support walls.

Steel I-beam Installed in Basement.
Steel I-beam Installed in Basement.

How to Reinforce Basement Beams?

Generally, it’s more economical to reinforce a basement beam than to replace it entirely.

Step 1: Installing New Jack Posts

When a basement beam is reinforced with steel plates, it makes it much heavier.

For this reason, the existing jack posts in the basement may be insufficient.

Therefore, install more jack posts and place them at equal intervals for efficient load distribution.

Also, check the alignment of the posts with a leveling instrument.

Step 2: Reinforcing with Metallic Plates

To reinforce the weakened sections of a basement beam, install metallic plates on both sides of it.

If necessary, a full-length steel plate may also be added for additional strength.

Drill holes at 8-inch intervals along the length of the plate and connect it to the sides of the beam using bolts.

Reinforcing Beam with Steel Plates.
Reinforcing Beam with Steel Plates

Alternatively, you can install additional beams or columns to improve the load-bearing capacity.

Overall, strengthening a basement beam is much more difficult compared to strengthening floor joists.

When Should You Replace the Basement Beams?

You should replace basement beams if they exhibit significant cracks and start settling.

Cracks in Basement Beams
Cracks in Basement Beams

Another sign that indicates the need to replace basement beams is excessive moisture that leads to the formation of mold and mildew growth.

A great way to prevent moisture from entering your basement is to construct a basement knee wall.

Pests can also deteriorate basement beams and necessitate the need for replacement.

Furthermore, if the steel beams rust and compromise the structural integrity, it is essential to replace them.

How Much Does it Cost to Replace Basement Beams?

A simple basement beam replacement project costs around $7000 to $8000 and varies with the complexity of the project.

Replacing a wooden beam with a newer one is simple and will not cost a lot.

However, replacing it with a steel beam increases the cost.

You may also enjoy reading:

Do You Need a Permit to Replace Basement Beams?

Yes, you require a permit to make any structural changes to the basement of your house.

In addition to the legal requirements, it ensures the stability of your home.

They can also increase the value of your homes.

Furthermore, during the sale, it is a legal requirement to disclose the repair details.

Therefore, unpermitted repairs can deter buyers and make it difficult to sell your home.

Frequently Asked Questions (FAQ)

What Kind of Steel Plates Should be Used to Reinforce Basement Beams?

Angle steel plates are the most preferred type of plates used to strengthen basement beams.

These plates are typically L-shaped and can be easily attached to beams using screws and bolts.

How Long Does it Take to Replace Basement Beams?

Basement beam replacement typically takes 7 to 14 days.

Consult a professional to know the accurate timeline.

How Long Do Wooden Beams Last?

The lifespan of wooden beams depends on the wood type, quality of construction, and environmental conditions.

Generally, wooden beams last around 50 years.

V Susan
Hi! I'm Susan. I am passionate about woodworking, general DIY and home improvement. If you'd like to connect with me or talk about something you like at mellowpine, drop me a mail at susan@mellowpine.com