Who to Hire to Replace the Subfloor in Your Home

If your plan to upgrade to new hardwood flooring hit a snag after discovering unruly and weathered floor joists, you’ll probably need to fork over more cash to reinforce your floor supports before moving forward with any finished flooring upgrade. Sagging floors usually indicate subflooring and floor joist issues. These repairs are significant and require the expertise of a carpenter—not a handyperson. 

Before laying down finished floors, hire a local carpenter specializing in unfinished work to help you with this major home improvement project.

Benefits of Hiring a Carpenter for Floor Joist Repairs

Carpenters specializing in unfinished work should efficiently inspect the structure and find the underlying cause of uneven joists.

If you sister or replace joists without checking for the main issue, you risk leaving the real problem unresolved and paying for a “bandaid” repair. Plus, in certain situations, sistering can damage the added support beams or new 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.

Even more, an experienced pro will complete the job quickly, so you can get back to living in your home uninterrupted—and finally choose what type of new flooring you want to lay down.

Can I Hire a Flooring Specialist for Subfloors?

Given the complexity of subfloor repairs, you should really stick with a carpenter for this project. But if you want to install a new subfloor or underlayment over sound floor joists, hire a local flooring contractor for this step. This project is essential to ensuring your floors are level and structurally sound.

Can I DIY Joist and Subfloor Repairs?

Subfloor repairs are one of the home projects we definitely recommend leaving to a professional. Attempting DIY joist repairs can be costly and dangerous. You’ll need a hydraulic jack if you plan to sister the joists, and materials alone may cost $300. You’ll also need to work around wiring and plumbing to make the repairs.

If you have a strong carpentry and remodeling background, you can save about $100 to $300 in labor costs per room by installing subfloors yourself. But tread with caution—mistakes may mean spending more money on subfloor materials, and not addressing the real issue could put you back at square one with uneven or sagging floors. Plus, this project can take several days for the average person.

If you’ve got your heart set on a DIY, opt to lay down your own flooring after a pro deems your subfloor and joists safe, which you can do for about $3 to $7 per square foot.

How Much Does Subfloor Repair Cost?

Replacing subfloors costs $3 to $10 per square foot or an average of $1,560. Different repair types may cost more or less, depending on the extent of the damage. For instance, floor joist replacement can hover between $100 and $300, but total replacement through the home may cost $3,000 or more.

Your actual out-of-pocket cost will depend on your home's location and labor costs in your areas, the size and placement of the area needing subflooring, and the materials you select.

DIY vs. Hiring a Pro

Very experienced DIYers with expert subflooring experience can attempt this project. However, if you lack those skills, hiring a professional rather than doing it yourself is better. Subfloor repairs involve a great deal of precision to ensure your floors remain safe and stable. Any mistakes in leveling or securing materials can lead to costly long-term issues, like uneven floors.

Additionally, pros have the experience to spot underlying issues novices may miss, from structural damage to mold. They are also up to speed on local building codes, ensuring the work is done right and up to current building standards.