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How To Tighten A Loose, Wobbly Toilet

The toilet seems to move now when I sit on it. It never did before. Why? I haven't gained THAT MUCH weight!

Hello, Weight Watchers!! Oh, you haven't put on a few hundred pounds in the last week? Then maybe we need to think about this! Below, we will discuss the why's, the how's, and what you can do to solve the problem!!

How does the toilet attach to the floor?

Toilets are attached to a metal or plastic collar known as a toilet floor flange. The flange itself is attached to the floor with screws. The flange leads to the soil stack, a large drain pipe designed to carry a large volume of liquid, etc. at high speeds. Thank goodness for that!!

Anyway, the floor flange and toilet bolt together with special bolts know as closet bolts. To seal the space between the two to prevent leakage, a ring made of wax called a (believe it!) wax ring is pressed onto the base of the toilet before placing the toilet over the floor flange. The ring is compressed between the base of the toilet and the floor flange, giving a long-lasting waterproof seal.

What can cause a toilet to loosen?

  • Loose closet bolts...

    Of the possible problems you could have, I would choose this one, assuming there are no leaks visible in the ceiling below or damage to the floor around the toilet

    On either side of the base of the toilet, you will most likely see little plastic "domes". These decorative covers conceal the closet bolts, and to some extent protect them from moisture. They can be pried off with a screwdriver. If the cover is missing (as they often are), then the bolts should be visible.

    Actually, you won't see the heads of the bolts, you will see the nuts and washers. The head of the bolt is slid into a slot in the floor flange. Tightening the nuts pulls the toilet and flange together, making a solid, non-moving seal with the wax ring.

    Try to tighten the nut by hand (clockwise). If it turns easily (be sure the bolt itself is not turning), you may have gotten lucky. Tighten both sides hand-tight, then use a small wrench to tighten both sides alternately, holding the end of the bolt with pliers. If the nuts won't turn easily by hand, hold the bolt with pliers and try to turn the nuts with a wrench. If you cannot turn the nuts to tighten them (is there any visible corrosion on them?), but the bolt is firm and not spinning, don't try to force them. Instead, apply some penetrating oil to them and let them sit for a few hours. Then try tightening them again.

    I can't tell you exactly how tight to turn them, but you should not overtighten, or you may crack the toilet. As a rule of thumb, try a turn or two a side until you feel resistance, them try to wiggle the toilet bowl slightly. If there is no significant movement, you are probably tight enough. This tightening operation is a "feel" thing you get from experience, so be conservative and use your best judgement.

    If the bolt spins freely and the nut won't tighten even if you hold the bolt with pliers, or if the bolt spins and the "last guy" cut the bolt off at the top of the nut so that you can't grip it, then you will have to remove the toilet and look underneath for the cause of the problem. You will probably have to drill off the nuts to release the toilet. See Removal of Toilet, Repair, and Reinstallation below!

  • Poor original installation...

    The floor flange is usually mounted on the floor (duh) during the original plumbing installation. However, if any additional subflooring (such as a smooth underlayment for vinyl flooring, or additional plywood to stiffen the floor for tile), tile, strip wood flooring, etc. is installed after the flange, what happens? Right... the toilet is now higher and further away from the flange. The wax ring the installer used may not be thick enough to give a good seal! Sure, it would last long enough for the "check to clear", but the probable seepage will cause problems that will be very severe later on!

    The easy solution is to stack two wax rings, or to purchase an especially thick ring designed for this circumstance. If you use two rings, be sure that you only use one with a neoprene sleeve and one plain ring. I'll go into more detail in the reinstallation section below.

    Of course, a more difficult alternative is to raise the flange to the new floor level. This may not be beyond your capabilities, but I don't want to go into it here, unless you email me and beg me to reveal my secrets. Then I'll expound on it for you!

  • Corrosion and breakage of the floor flange...

    I hate this one!! I guess I hate it because it is the worst possible thing that can happen, and it is 99% preventable. If the original installer did his job right, and the toilet is checked for looseness every couple of years, this problem would rarely occur. Wax rings do not wear out! Only movement can cause a good seal to break, and a lot of it!

    About the only circumstances that could cause a floor flange to corrode and break that are not related to wax ring leakage would be

    • Unnoticed leaking from the tank-to-bowl seal over a long period of time. A slight leak each time you flush that drips behind the tank might go unnoticed for years!!
    • Dripping at the inlet valve connection, or the shutoff.
    • Condensation (sweat) dripping from the tank and making it's way under the toilet to the floor flange.
    • Slopping excessive water under the bowl when washing the floor.

Many manufacturers and installers recommend sealing the perimeter of the toilet after bolting it down with a clear or colored caulk, or applying plumbers putty to the base of the toilet before installing it. This both protects the flange from moisture and prevents small spills from creeping under the toilet and/or dripping on the ceiling below (you know, follow the path of least resistance).

If the toilet is mounted on tile, some installers will put some of the matching floor grout under the toilet if there is any unevenness in the floor that might cause the toilet to rock on the tile. This, of course, also helps to keep moisture out from under the toilet.

Removal of toilet, repair and reinstallation...

If you made it this far, you have my sympathy. You are now going to enter a strange new world that few people see, the world under the toilet!!


  • Shut off the water supply to the toilet and disconnect the supply tube from the inlet valve.
  • Flush the toilet. Sponge out remaining water from tank and bowl.
  • Remove decorative covers from closet bolts.
  • Unscrew the nuts if possible. If not, try to pull them up enough with pliers to get a hacksaw under them. Then, cut off the bolts below the nuts, being careful not to scratch toilet. If the nuts don't lift at all, you can drill them off. Use a 1/8" sharp bit to drill a hole in the nut right where the nut meets the bolt. Then, enlarge the hole until either the nut or the bolt fall free.
  • Put a large towel or tarp in the place you wish to put the toilet when you pull it off.
  • Look at the base of the toilet to see it there is any caulk or other material sealing it to the floor. You can use a utility knife to cut the caulk around the base If that is too awkward, you can also run a thin putty knife or flexible scraper under the perimeter of the base to free it up
  • Lift the toilet from the floor with a slight twisting and rocking motion. The slight twist will break any remaining seal between the toilet and floor, hopefully. Put the toilet on the tarp.
  • Look at the floor flange area. Is it very wet? Are the tiles loose? Is the wood subfloor soaked or rotten? Is the flange severely rusted or broken? Is there a hundred dollar bill rolled up next to the flange (an old plumber's trick!!)? You may see any or all of these things. Each one demands its own repair before you can reinstall the toilet (Except for the C-note, which you can donate to your favorite

Repair and preparation...

Return to the question list or index to find the necessary repair, then come back here to reinstall the toilet.

Reinstallation of the toilet...

Welcome back. I have to assume that you are here because you have solved the problems you found when you took out the toilet, or you are just visiting here from the Natural Handyman's Home Repair Index to get my take on installing a toilet.

These are the materials you will need...

  • New closet bolts. Don't get cheap on me now!!
  • Wax ring (single, double, or extra thick) with neoprene sleeve. If you are doubling rings, only use one with a neoprene sleeve on the bottom towards the flange, and use a plain wax ring for the top. Always replace the wax ring, even if you just pulled the toilet off to inspect for leaks!
  • New supply tube (unless you are doing a simple reinstallation of the same toilet or same brand of toilet without doing any significant floor repair, such as to do a wall repair behind the toilet, wallpaper, panelling, painting, etc.). If you do use the old supply tube, replace the washer if it has one.

By the numbers...

  1. All repairs on floor and walls must be complete and all glues, caulks, or grouts dry. If you are going to paint or wallpaper, it's easier to do with the toilet out. If you are going to tile or install vinyl flooring, do it before installing the toilet (unless, of course, you're like me and see the completion of this project a long, long time in the future... but you sure need that extra toilet!!)
  2. Test fit the toilet over the flange. Is it solidly planted on the floor, or does it rock? This is not uncommon if your house was built in the late 60's (bad hippy joke), or if you are working on a tile floor or repair job. If the rocking is slight, you will need to caulk under the toilet at the end to firm it up. Or, if on tile, you can mix up a small batch of grout (never mix less than two cups for proper ingredient proportions) and force it under the toilet after installation is complete.
  3. Gently lay the toilet on its side or back, and clean up around the hole in the toilet bowl base, if you haven't done so already. It doesn't have to be virginal, just remove the worst of the remnants of the old wax ring and assorted other goodies that may be there. Apply the new wax ring (go with a double ring or extra thick ring if the floor has be raised more than 1/2" above the top of the flange) onto the toilet base around the hole. Because the wax ring is a viciously sticky thing, try to handle it as little as possible by leaving part of the packaging it comes in on the outside as you press it into place on the toilet.
  4. Get the new closet bolts you bought, and insert them into the keyhole-like blot slots (see graphic in Title Frame above on each side of the floor flange. Some of the more thoughtful companies supply little ribbed plastic washers that will help hold the bolts vertical while you place the toilet down onto them and the flange. If you don't have this type, you can get a small square of cardboard, no more than 3/4" square, and poke a hole in it just a bit smaller than the bolt size. Press the bolt through it most of the way, then install the bolt in the cutout of and press the cardboard down on to the flange to hold the bolt in place.
  5. Align the bolts so they are approximately opposite each other on the floor flange and are an equal distance from the wall. This is not extremely critical, just a starting point for the final adjustment which will be made once the toilet set onto the flange.
  6. Lift the toilet so it is positioned over the floor flange, and lower it carefully onto the flange. The two closet bolts should come through the holes in the base of the toilet. This is a real pain-in-the-butt routine, but somebody's got to do it!! If you miss, keep trying until you get it right.
  7. Once the bolts protrude through the holes in the base, press down and very slightly rock the toilet until it bottoms out onto the floor. The wax ring has a lot of give, so you should now position the toilet in relation to the wall. If you are going to try to use the old supply tube, make sure it aligns with the bottom of the inlet valve as you adjust the toilet into its final position. You can even screw the coupling nut on a few turns.

    If you are reinstalling a toilet after doing a serious floor repair, or if you are installing a new toilet, I would recommend installing a new supply tube.

  8. Put the plastic base for the decorative cap on first, then the flat washer, and then the nut. Do both sides hand tight. Then, doing a turn or two a side, alternate tightening the nuts until the toilet is firmly pressed to the floor. You can check by trying to rock the toilet. If it is firm and unyielding, you're probably tight enough. It is possible to break the toilet by overtightening, so don't tighten more than necessary!!
  9. Tighten up the coupling nut on the supply tube to the inlet valve, if you are reusing the old supply tube, or install the new one. More tips on supply tube installation
  10. Slowly turn on the water. The tank should start to fill. Check for leaks. When the toilet fills about a third, depress the flush handle to drain the tank. Look for any leak around the base of the toilet.
  11. If there are no leaks, turn the water on fully and allow the tank to fill till the inlet valve shuts off. Do another flush and check for base leaks again.
  12. If everything checks out OK, now is the time to caulk around the base of the toilet, if you care to. If the toilet rocked back in your test fit in Step (2), I would recommend that you either caulk or, if the floor is tile, grout abound the base to stabilize the toilet. Yes, the toilet may appear firm now that it is bolted down, but the fact is that the irregularities around the toilet base will eventually cause the toilet to loosen and leak!
  13. Let the caulk or grout dry for 24 hours before sitting on the john. Vertical use is acceptable (sorry, ladies!).
  14. I'm not the superstitious sort, but I just couldn't let you finish this project on step 13. Oh boy, watch out for that black cat!

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