If you hear rattling every time you walk around a corner, the floors are probably getting by with minimal support. Bouncy floors cause furniture and other items to shake and vibrate due to inadequate support. If the floors do not feel firm, that's a sign the floor joists need more support.
The first thing you will want to do is determine the condition of your joists. This will help you assess whether you need to repair, support, or replace them. A common sign of compromised joists is uneven floors. But these could be the result of flooring or subflooring defects.
It will typically cost between $1,000 and $10,000 or more to repair floor joists, depending on the extent of the damage and the size of your room. Noticeable issues should be addressed so you know whether the damage needs to be repaired immediately.
If your floors feel like they are bouncy, uneven, and sagging, you could have a problem with the floor joists and support system underneath your house. Wooden supports can easily rot and fail in problematic crawl spaces with open vents, high humidity, and standing water.
We do not recommend trying to remove and replace the rotten floor joist yourself. Once you identify the problem, or if you want to call professionals to find the problem, you can be sure that highly-trained contractors will do the best job possible.
The best way to repair deck joist rot is to sister new treated lumber onto a deck joist that has minimal wood rot. If just the top 1 inch of the joist is rotted, you can repair the rotted deck joist by screwing on a treated 2x4 to the existing floor joist.
Joists can be located by either tapping across the ceiling with a knuckle or with an electronic stud finder. With a knuckle you tap across until a more solid sound is heard – this is a joist or beam. A hollow sound is the space between the joists.
A reputable carpenter will know the right way to safely repair the joists, working around obstacles like plumbing and wiring without causing more costly damage to your home.
When floor joists are affected by dry rot, they become spongy, soft, and cracked. This is bad news for your home because floor joists hold up the weight of furniture and moving people in your living space. Damaged floor joists will bend under this weight and, in worst-case scenarios, collapse as a result.
Foundation damage caused by shifting or settling earth or sagging floors caused by rotting floor joists are typically not covered by homeowners insurance. If the damage is caused by flooding or an earthquake, you'll typically require separate coverage.
In general, homeowners insurance covers subfloor water damage. However, it must be caused by one of the perils listed in your insurance policy. If you have an HO-2 policy, your building, including the floor, is protected against various threats, such as a ruptured water heater or pipe.
High Humidity
For example, uncovered crawl space vents or loose vent covers and crawl space doors can let water into your home and increase humidity. Over time, this kind of humidity can cause a damp environment and allow fungal spores to take root, thus spreading in exposed wooden joists.
Unfortunately, floor joists can rot and decay and this can lead to serious structural problems, including: Slopping, sagging, or uneven floors. Skewed or uneven window and door frames. Tilting or sinking crawl space supports.
The most common floor joist repair option for homeowners is sistering the floor joist. In this process, a new piece of lumber is attached to the failing floor joist to provide additional support without having to replace the entire thing.
If they really are solid then no they don't need to be replaced. You should though isolate them from touching the walls using a physical DPC . When this is done they will dry out in time. If there is any woodworm or fungal decay they you must have them treated as well.
Replacing a floor joist is a big job. If you don't have any carpentry experience, you may want to call a professional carpenter to handle the project. Replacing a floor joist incorrectly may weaken the structural integrity of your house, putting your safety and your house's value at risk.
A joist is a horizontal structural member used in framing to span an open space, often between beams that subsequently transfer loads to vertical members. When incorporated into a floor framing system, joists serve to provide stiffness to the subfloor sheathing, allowing it to function as a horizontal diaphragm.
Carl Hagstrom responds: The rule of thumb that I like to use when sizing uniformly loaded residential floor joists is "half the span plus two." First, round the clear span of the floor joist up to the nearest foot, and divide by two. Then add two to the answer.
A stud finder locates concealed studs and joists inside a wall or ceiling using electronic sensors or magnets. Magnetic stud finders detect the stud by the nails and screws holding it in place, while electronic sensors use changes in electrical flow to "see" wood, metal, and sometimes electrical wiring within the wall.
Spacing between joists is also an important factor to consider. Standard spacing for joists on 16-inch centers is ideal for most residential applications, while 24-inch centers are allowable under some conditions.
If the rotten wood and rot exposure has left your Joists weaker than before, your joists may benefit from attaching reinforcing wood or boards. Cut your pressure treated wooden board to the correct size for your Joist, and fit it securely to the side of the supporting structural component, using nails or screws.
To repair floor joists, the damaged joist is sistered together with a new piece of wood. Usually, the new piece of lumber spans the length of the old one. At times when this isn't possible, shorter pieces are used instead (this is sometimes referred to as scabbing).