Leveling 2nd Story Floors: DIY Guide (9 Subfloor Tips!)

I’m a flooring contractor, and I’ve seen it all – from perfectly level surfaces to floors that resemble a rollercoaster.

Leveling a second-story floor is a unique beast in the home improvement world. It’s not just about aesthetics; it’s about structural integrity, safety, and overall home value.

I remember one client, Sarah, who was constantly tripping over a slight dip in her bedroom floor. Her furniture wobbled, and she was worried about potential structural damage.

Addressing uneven floors is crucial. Ignoring it can lead to:

• Safety hazards: Tripping, especially for kids and the elderly.
• Furniture damage: Wobbling can stress joints and cause breakage.
• Decreased property value: Uneven floors are a red flag for potential buyers.

This guide empowers you to tackle this challenge effectively. I’ll walk you through each step, sharing my pro tips and tricks along the way. Get ready to roll up your sleeves and transform your home!

Section 1: Understanding the Importance of Level Floors

Why are level floors so important, especially on the second story? Well, think about it.

The second story carries a lot of weight – furniture, people, and the structure itself. Uneven floors can indicate deeper problems with the framing or foundation.

Ignoring uneven floors can lead to:

• Structural issues: Over time, the unevenness can stress the floor joists and subfloor, leading to sagging or even collapse.
• Safety hazards: As I mentioned before, tripping is a serious concern.
• Decreased property value: A sloped floor is a major turn-off for potential buyers.

Beyond the structural aspects, level floors enhance comfort and usability. Imagine trying to place a bookshelf on a sloped surface – not fun, right?

Leveling your floors makes furniture placement easier, improves the overall aesthetics of your home, and creates a more comfortable living space.

It’s like giving your home a solid, stable foundation from the inside out.

Section 2: Identifying Signs of Uneven Floors

How do you know if your second-story floor needs leveling? Here are some tell-tale signs:

• Visual cues:

  • Gaps between the floor and baseboards: These gaps often indicate that the floor is sinking or shifting.
  • Sloping surfaces: Use a level or your eye to spot any noticeable slopes.
  • Visible sagging: Look for areas where the floor dips noticeably.

• Auditory clues:

  • Creaking sounds: Creaking can indicate that the subfloor is rubbing against the joists due to unevenness.
  • Squeaking: Similar to creaking, squeaking can point to movement and friction.

• Other indicators:

  • Doors that stick or don’t close properly: An uneven floor can throw door frames out of alignment.
  • Wobbly furniture: If your furniture rocks back and forth, it’s a sign that the floor isn’t level.

Assessing the severity is key. Minor dips might be manageable with DIY methods, but significant slopes or structural concerns warrant professional attention.

As a rule of thumb, if the slope is more than 1 inch over 6 feet, I recommend consulting a structural engineer or experienced contractor.

It’s always better to be safe than sorry when it comes to structural integrity!

Section 3: Tools and Materials Needed

Alright, let’s talk tools and materials. Here’s a comprehensive list to get you started:

Essential Tools:

• Level: A 4-foot level is ideal for checking the floor’s levelness.
• Measuring tape: For accurate measurements.
• Straightedge: A long, straight piece of wood or metal to identify high and low spots.
• Drill/Driver: For screwing down shims or plywood.
• Circular saw or jigsaw: For cutting plywood.
• Hammer: For tapping in shims.
• Safety glasses: Protect your eyes from debris.
• Dust mask: To avoid inhaling dust.
• Gloves: To protect your hands.
• Floor scraper: If you need to remove old adhesive.
• Shop vacuum: For cleaning up dust and debris.

Materials:

• Shims: Tapered pieces of wood to fill gaps and raise low spots.
• Plywood: For adding support and creating a level surface. I recommend using ¾-inch plywood for most applications.
• Self-leveling compound: A liquid mixture that spreads out and hardens to create a level surface.
• Construction adhesive: To secure shims and plywood.
• Screws: For attaching plywood to the subfloor.

Cost and Where to Find Them:

You can find most of these tools and materials at your local home improvement store (like Home Depot or Lowe’s).

The cost will vary depending on the quality and quantity of materials you need. Expect to spend anywhere from $100 to $500, depending on the size of the area you’re leveling.

Investing in quality tools is essential. A good level, for example, will ensure accurate measurements and a more successful leveling project.

Don’t skimp on safety gear either. Safety glasses, a dust mask, and gloves are a must!

Section 4: Preparing the Workspace

Before you start swinging hammers and pouring self-leveling compound, you need to prep the workspace.

Here’s a step-by-step guide:

1. Clear the area: Remove all furniture, rugs, and other items from the room.
2. Remove existing flooring: If you have carpet, tile, or other flooring, remove it to expose the subfloor.
3. Clean the subfloor: Sweep or vacuum the subfloor to remove dust, debris, and any loose particles.
4. Inspect for damage: Look for signs of moisture damage, rot, or insect infestation. Address these issues before proceeding with leveling.
5. Ventilate the area: Open windows and doors to provide adequate ventilation, especially when working with self-leveling compound.

Safety Precautions:

• Wear safety glasses: Protect your eyes from flying debris.
• Wear a dust mask: Avoid inhaling dust, especially when sanding or scraping.
• Wear gloves: Protect your hands from chemicals and sharp objects.
• Use power tools safely: Follow the manufacturer’s instructions and wear appropriate safety gear.
• Ensure proper ventilation: Self-leveling compound can release fumes, so make sure the area is well-ventilated.

A clean and well-prepared workspace is crucial for a successful leveling project. It allows you to work efficiently, identify potential problems, and ensure a safe working environment.

Section 5: Assessing the Subfloor

The subfloor is the foundation upon which your finished floor rests. Assessing its condition is crucial before you start leveling.

Here’s what to look for:

• Moisture damage: Check for water stains, discoloration, or soft spots. Moisture can lead to rot and structural problems.
• Rot: Rotting wood is weak and can’t support weight. Probe the subfloor with a screwdriver to check for soft, crumbly areas.
• Insect infestation: Look for signs of termites, ants, or other wood-boring insects.
• Inadequate support: Check for sagging or deflection between the floor joists. This can indicate that the joists are undersized or spaced too far apart.
• Loose or damaged fasteners: Make sure the subfloor is securely attached to the joists. Replace any loose or damaged screws or nails.

Addressing these underlying issues is essential before proceeding with leveling. Ignoring them can lead to:

• Continued settling: If the subfloor is rotting, it will continue to deteriorate, causing the floor to sink further.
• Structural instability: A weak subfloor can’t support the weight of the finished floor and furniture.
• Mold growth: Moisture in the subfloor can lead to mold growth, which can cause health problems.

If you find significant damage, consult a professional contractor to assess the extent of the problem and recommend appropriate repairs.

Sometimes, replacing sections of the subfloor is necessary to ensure a long-lasting and stable foundation for your new floor.

Section 6: The Leveling Process: Step-by-Step Guide

Now for the fun part – leveling the floor! Here’s a detailed, step-by-step guide:

1. Measure the floor: Use a level and straightedge to identify the high and low points. Mark these areas with a pencil.
2. Determine the amount of leveling needed: Measure the difference between the high and low points. This will determine how much shimming or self-leveling compound you need.
3. Shimming (for minor unevenness):
   • Cut shims to the appropriate size.
   • Apply construction adhesive to the shims.
   • Slide the shims under the low spots, gradually raising the floor until it’s level.
   • Secure the shims with screws.
4. Jacking (for more significant unevenness):
   • Use a floor jack to carefully lift the floor joists.
   • Insert shims or additional support under the joists to maintain the raised level.
   • Slowly lower the jack, ensuring the floor remains level.
5. Plywood (for added support):
   • Cut plywood to fit the area you’re leveling.
   • Apply construction adhesive to the subfloor.
   • Lay the plywood over the adhesive, ensuring it’s flush with the surrounding floor.
   • Secure the plywood with screws.
6. Self-leveling compound (for overall leveling):
   • Prepare the compound according to the manufacturer’s instructions.
   • Pour the compound over the area you’re leveling, allowing it to spread out and fill in the low spots.
   • Use a gauge rake to help spread the compound evenly.
   • Allow the compound to dry completely before proceeding with the next step.

Tips for Ensuring an Even Surface:

• Use a laser level: A laser level can help you accurately determine the high and low points of the floor.
• Check your work frequently: Use a level to check the floor’s levelness throughout the process.
• Don’t rush: Take your time and work carefully to ensure a smooth and even surface.

Leveling a floor takes patience and attention to detail. But with the right tools and techniques, you can achieve professional-looking results!

Section 7: Finishing Touches

You’ve leveled the floor – now it’s time for the finishing touches!

Here’s what to do next:

1. Inspect the leveled surface: Make sure it’s smooth, even, and free of any imperfections.
2. Prepare the surface for flooring: Depending on the type of flooring you’re installing, you may need to sand, prime, or apply a moisture barrier to the leveled surface.
3. Install new flooring or reinstall existing flooring: Follow the manufacturer’s instructions for installing your chosen flooring.
4. Ensure a smooth transition: Use transition strips to create a smooth and seamless transition between the leveled floor and adjoining areas.

Tips for a Smooth Transition:

• Use transition strips: Transition strips are designed to bridge the gap between floors of different heights or materials.
• Feather the edges: If you’re using self-leveling compound, feather the edges to create a gradual transition.
• Use a router: A router can be used to create a smooth, beveled edge on the flooring.

The finishing touches are what make your leveling project truly shine. Take your time and pay attention to detail to ensure a professional-looking result.

Section 8: Maintenance Tips for Long-Lasting Results

You’ve invested time and effort into leveling your floor – now it’s important to maintain it properly to ensure long-lasting results.

Here are some maintenance tips:

• Regular inspections: Periodically inspect your floor for signs of settling, shifting, or moisture damage.
• Moisture control: Prevent moisture from accumulating under the floor by addressing any leaks or plumbing issues promptly.
• Proper cleaning: Clean your floor regularly with a recommended cleaner.
• Avoid excessive weight: Distribute heavy furniture evenly to prevent concentrated pressure on the floor.

Spotting Early Signs of Settling or Shifting:

• New cracks in the walls or ceiling: These can indicate that the floor is settling.
• Doors or windows that stick: Settling can throw door and window frames out of alignment.
• Changes in the levelness of the floor: Use a level to check for any changes in the floor’s levelness over time.

Addressing issues early can prevent them from escalating into more serious problems. If you notice any signs of settling or shifting, consult a professional contractor to assess the situation and recommend appropriate repairs.

Conclusion

Congratulations! You’ve successfully leveled your second-story floor. Take a moment to appreciate the pride and satisfaction that comes from completing a DIY project.

Enjoy the benefits of your hard work – the improved comfort, safety, and aesthetics of your living space.

Remember, with the right knowledge and tools, you can tackle even complex home improvement projects. Transforming your home into a more functional and beautiful space is within your reach.

So, go ahead and enjoy your newly leveled floors! You deserve it!

Learn more