How to Fix Sagging Floors

Sagging floors can be dangerous for people with mobility issues and reduce a home’s value, becoming worse over time if left uncorrected. The longer this issue goes unaddressed, the worse its effects become.

Sagging floors may be common, but should never be taken for granted. Professional assistance should always be sought immediately in order to address them quickly before becoming an imminent safety hazard.

Inspect the Subfloor

Before beginning to repair sagging floors, it is vital that you perform an in-depth examination of the area beneath your home. Start by searching for any areas in which floor joists have become cracked or rotten – these could be at the core of why your floors sag in certain spots. In addition, check if any cuts were improperly made for pipe, wires or HVAC duct installation.

Once this step is taken, the next step should be identifying the appropriate method of repair for your sagging floors. There are four basic approaches available for fixing this condition; which method best fits with your home will depend upon its extent and cause of sagging floors. Each involves some form of lifting action such as replacing compressed sill plates, sistering (reinforcing) floor joists or raising beams under your home.

Expert inspection is key to early detection of your floors sagging. Without one, your eye might miss any subtle decline and knowing when the floors begin to sag is difficult without professional assistance from crawl space repair specialists. With their assistance you will know when it is necessary to take action before your sagging floors become an imminent risk to elderly family members, toddlers or anyone with mobility issues in your home.

Remove the Sagging Joists

Sagging floors can be an acute threat that requires immediate professional intervention. Left unattended, this issue will only worsen over time and eventually collapse altogether. Luckily, the cost associated with correcting this problem may not be as great as you initially think.

Experts advise conducting a detailed inspection of the floor joists and support beams beneath, inspecting for signs of damage or inadequate support, such as soft wood, rotted timbers or insects infestation (termites or carpenter bees). Furthermore, take note of your foundation or crawl space’s condition; shifting soil could place additional stress on subflooring joists that eventually weaken over time, contributing to sagging floors.

Before cutting into floor joists to run pipes or wiring, homeowners should also inspect whether other areas of their home provide support – walls or plumbing for instance – which will help ensure any potential joist issues don’t arise later on. It can be tempting to cut into floor joists to run pipes or wiring through them but this can weaken structural integrity, creating issues later down the line.

After you have repaired or replaced damaged or rotten joists, it will also be important to install blocking between pairs of joists. Use 2-by stock with width equal to that of each joist to create blocks and screw them into position – these will add strength and stiffening capabilities that help resist movement of joists; experts at your local flooring store can advise you as to which size and placement will best meet this goal.

Install New Joists

Floor joists often become damaged from overloaded loads caused by new appliances, additions like fireplaces or structural modifications, or simply having more furniture than intended. A quick inspection should reveal whether your load has become too great to bear.

If a single joist is sagging, you can fix it by installing “sister” joists. This involves taking care to treat any damaged wood before placing an identical sister joist adjacent to it to transfer loads away from its previous member and keep flooring above stable.

This method might not stiffen your floor as much, but it’s a good place to start if money is tight and more extensive repairs aren’t feasible. Installing bridging between the joists may also help stiffen floors if their original bridging has loosed over time or been completely absent; just place rows at one-third points along your joist span (e.g. 4ft and 8ft from foundation wall) until bridging has secured itself to stiffen it completely.

If your joists are damaged beyond repair or the problem is severe enough, installing structural jack posts might also be an option – though this process should be left to an experienced professional.

Install Structural Jack Posts

Older homes typically had floor joists spaced further apart than what current building codes call for, which results in too great of a span for their support to handle and ultimately leads to sagging floors. To resolve this problem quickly and cost effectively, support posts may be installed beneath the floor surface.

Before undertaking any repairs, it’s essential to determine the cause of sagging floors. A professional should inspect both under- and over-levels to assess what support may be necessary to eliminate a sag in the floor and lift it back into its proper place. Living with an unstable floor could result in major damage to both walls and other parts of your house if left unaddressed.

Professionals should inspect both the joists and sills that support a home. Rotten or cracked joists could be one of the causes for floors sagging; additionally, sills may have been damaged due to water, termites or other sources.

Once professionals have determined the cause of sagging floors, they can begin repair efforts. The first step will be installing a temporary jack post beneath any joists that have begun sagging by digging a hole six inches deeper than their existing post and placing the temporary post with its footing into concrete – before gradually raising it until it meets with the floor level.