Shimming a toilet involves inserting thin, wedge-shaped pieces of material under its base to eliminate wobbling and create a stable, level installation. This simple fix prevents potential plumbing issues and ensures your toilet sits securely on the floor.
Why Your Toilet Might Need Shimming
A wobbly toilet isn't just annoying; it can lead to serious problems over time. The primary reasons a toilet might wobble include:
- Uneven Flooring: The most common cause is an uneven subfloor or finished floor beneath the toilet's base, creating small gaps.
- Loose Flange Bolts: The bolts securing the toilet to the floor flange may become loose, allowing the toilet to shift.
- Damaged Flange: A damaged or improperly installed toilet flange can prevent the toilet from sitting flush.
- Worn Wax Ring: While not a direct cause of wobbling, a persistent wobble can eventually compromise the wax seal, leading to leaks.
Essential Tools and Materials
Before you begin, gather the following:
- Toilet Shims: These are wedge-shaped pieces specifically designed for leveling. They come in various materials, each with unique properties.
- Level: A standard spirit level (2-foot recommended) to check for evenness.
- Utility Knife or Snips: To trim excess shim material.
- Adjustable Wrench or Socket Wrench: To tighten flange bolts.
- Gloves: For hygiene.
- Putty Knife (Optional): To help guide shims or remove old caulk.
- Caulk Gun and Waterproof Caulk (Optional): For sealing the base after shimming.
Types of Toilet Shims
Choosing the right shim material can impact durability and ease of installation.
| Shim Type | Material | Advantages | Disadvantages |
|---|---|---|---|
| Rubber | Rubber | Durable, flexible, excellent grip, water-resistant | Can be slightly harder to trim precisely |
| Plastic | Plastic | Easy to cut, water-resistant, inexpensive | Can be brittle, less grip, may slide if not snug |
| Wood | Wood | Readily available, easy to cut | Can rot if exposed to moisture, less durable |
Step-by-Step Guide to Shimming a Toilet
Follow these steps to effectively shim your toilet and restore its stability.
Step 1: Prepare the Area
- Clean Around the Base: Ensure the area around the toilet's base is clean and free of debris. If there's old caulk, carefully remove it with a utility knife or putty knife.
- Inspect Flange Bolts: Check the caps covering the toilet flange bolts. Remove them to access the bolts.
Step 2: Identify the Wobble and Gaps
- Rock the Toilet: Gently rock the toilet from side to side and front to back. Pay close attention to where the gaps appear under the base and where the wobble is most pronounced. This will tell you where the shims are needed.
- Check with a Level: Place a level across the rim of the toilet bowl from front to back and then side to side to confirm how uneven it is.
Step 3: Insert the Shims
- Slide Shims into Gaps: Carefully slide your chosen shims into any identified gaps beneath the toilet's base. Focus particularly on areas along the back of the toilet where wobbles often originate, inserting shims as required to fill the voids.
- Layer as Needed: For larger gaps, you may need to layer multiple shims or use a thicker shim. Ensure the shims are snug but not so tight that they lift the toilet off its main support points.
- Check for Stability: As you insert shims, periodically check the toilet's stability by gently rocking it. Continue adding shims until the wobble is minimized or eliminated.
Step 4: Level and Retighten
- Confirm Levelness: Once the toilet feels stable, use your level again across the bowl's rim to ensure it is level in all directions. Adjust shims as necessary.
- Retighten Flange Bolts: After inserting the shims and confirming the toilet is stable and level, proceed to retighten the flange bolts using your wrench. Tighten them evenly, alternating between the two bolts. Do not overtighten, as this can crack the porcelain base of the toilet. The goal is snug, not excessively tight.
Step 5: Trim Excess Shim Material
- Cut Off Protruding Parts: Use a utility knife or snips to carefully trim any parts of the shims that are protruding from under the toilet base. You want the shims to be invisible or barely visible. Take care not to scratch the toilet or the floor.
Step 6: Seal the Base (Optional, but Recommended)
- Apply Caulk: For a finished look and to further stabilize the toilet, apply a bead of waterproof caulk around the entire base of the toilet where it meets the floor. Use painter's tape to create clean lines if desired.
- Leave a Gap at the Back: It's good practice to leave a small gap (about 1-2 inches) in the caulk at the very back of the toilet. This allows any future leaks to be detected more easily, preventing water damage from going unnoticed.
Tips for a Stable Toilet Base
- Don't Overtighten: Always be careful not to overtighten the closet bolts, as porcelain can crack under too much pressure.
- Check Annually: It's a good idea to check your toilet's stability annually, especially if it's in a high-traffic bathroom, and re-shim if necessary.
- Consider Floor Repair: If your floor is severely uneven, shimming might be a temporary fix. In such cases, addressing the underlying floor issue might be a more durable solution. For complex repairs, consider consulting a professional.
