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Daily Archives: March 15, 2023


How Much Does It Cost to Replace Floor Joists?

Timber floor framing is mostly made up of timber joists, running side by side and having the same distance at regular intervals. Joists cover the areas from end to end of supports, such as walls, girders, foundations and beams. Typically, floor joists are 2 x 8s, 2 x 10s, or 2 x 12s. Normal spacing is 16 inches from the centre to the centre. The sizing and spacing of joists are decided by local and state building codes based on engineering requirements.

Newcastle Frame and Truss manufactures and supplies floor joists. These are boards that are arranged sideways, supporting the floor and are installed with the overall frame structure. These are strong boards, bolted into a sill, which is a piece of wood that runs along the walls. Joists also support the entire weight of the room that’s above them, so they are the essential parts of a structurally engineered sound home.

Reasons for Replacing Timber Floor Joists

1. Age and Decay

One of the primary reasons why timber floor joists may need to be replaced is due to age and decay. Over time, the timber may begin to rot or weaken due to moisture, pests, or other environmental factors. This can lead to a loss of structural integrity and make the floor unsafe to walk on. If you notice any signs of decay, such as soft or spongy floorboards, it is important to have your floor joists inspected by a professional.

2. Sagging Floors

If you notice that your floors are sagging or uneven, it may be a sign that your timber floor joists have become weakened or damaged. This can occur due to a variety of reasons, including excessive weight on the floor or structural damage to the foundation. If left unaddressed, sagging floors can lead to further structural problems and may require costly repairs in the future.

3. Pest Infestations

Pests such as termites or carpenter ants can cause significant damage to timber floor joists. They can weaken the timber by eating away at the wood, which can lead to a loss of structural integrity. If you suspect that your home has a pest infestation, it is important to have your floor joists inspected as soon as possible.

4. Incorrect Installation

If your timber floor joists were not installed correctly, it can lead to a range of structural problems. For example, if the joists were spaced too far apart, they may not provide adequate support for the floorboards above. Alternatively, if the joists were not properly secured to the foundation, they may shift or move over time, leading to a loss of stability. In cases where the installation was done incorrectly, it may be necessary to replace the entire flooring system.

If you have damaged flooring in your existing home or property, maybe due to water from flood or damage done by termite or other pests, then you may be thinking of replacing the joists. Other homeowners may be asking the question, whether they should repair or replace the flooring? Of course, the answer to their question depends on a number of factors, such as the type of flooring in your home and the extent of the damage. Once you have completely identified the problem, repair or replacement should be done immediately.

The cost of repairing floor joists differ widely, because of these two main reasons. First, if the damaged floor joists can be accessed from the basement or crawl space below or from the lower level of your home, you might not have to replace the flooring above the joists.

Second, if you only have to sister floor joists (you place a second joist next to the one that needs to be replaced and bolting them together for support), you’ll spend less money than having the original joists replaced.

Floor JoistsThe cost of replacing the joist will depend on the size of the area. However, sometimes replacing them may require using steel jacks to lift the home off the original joist. In this case, you might have to look at added costs. Newcastle Frame and Truss can help with a cost estimate and a budget to meet your needs.

Damaged joists are immense issues, so it would be best to contact the structural engineers at Newcastle Frame and Truss. Floor joist problems should not be left and must be addressed immediately.

Newcastle Frame and Truss is a trusted name, when it comes to manufacturing structures, such as wall framesroof trusseswall cladding, floor joists and other services. We engineer and design your timber floors to attain structural compliance, including fire, acoustic and thermal performance.

We use only timber that are sourced sustainably, as part of our responsibility to the environment. We would like to give you peace of mind, knowing that only the products that are suitable for your project are used.

Contact us for a fast quote today, at 0437 437 231 or if you would like to learn more about our products and services, you can visit us at

We service Broadmeadow, Northern Sydney, Callaghan, Adamstown Heights, Beresfield, the Hunter Region, Birmingham Gardens, Bar Beach, Adamstown, Wyong, Newcastle, Black Hill and surrounding areas.