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How Tight Should Toilet Tank Bolts Be [7 Important Tips]

When it comes to installing toilet tanks, you may face difficulties. And, it’s natural to face problems, as you are not professional.

You can install it on your own. To do so, you must follow a few measures in order to avoid cracking the toilet. 

The question that can arise while installing toilets is, how tight should toilet tank bolts be? 

The toilet will crack if the bolts are tightened too much. It’s best to use your hands to install the bolts. Then with a wrench, a quarter turn should be enough. If the tank wobbles slightly, it is not a problem. But, if it wobbles significantly, then tighten the bolts without deforming the washer.

Now, to install the toilet properly, you need to learn more. That’s why we’ve broken down the stages into easy-to-understand portions.

We hope you will stick around!

How Tight Should Toilet Tank Bolts Be

Porcelain is used to make toilets and these can break easily. For which it is important to be very careful while tightening the toilet tanks. 

Hand-tightening the nuts on the tank bolts is the best way to do it. Then use a wrench to turn the bolts a quarter-turn each. Check to see whether the tank wobbles or leaks once you’ve finished this. 

Tighten the bolts gradually if the tank appears loose or does not seal water within. Ensure that all tank bolts are tightened uniformly to avoid unequal tension that could crack your toilet. 

Once you have secured it, observe for the next 24 hours. If it leaks, then tighten the bolts gently until the leak stops.

What Will Happen if Toilet Tank Bolts are Too Tight

Toilet tank bolts that are over-tightened might break the toilet tank. Porcelain is usually a hard material. So toilets are made of this component but it is fragile enough to crack. An over-tightened bolt will break porcelain because it does not bend or flex.

Best Practise to Tighten the Toilet Tank Bolts

Working with small tools to tighten toilet tank bolts is the best approach. Using a large wrench will provide pressure to the toilet bolts, though it’s unintentional. Use a little wrench for this delicate work.

7 Tips for Properly Tighten Toilet Tank Bolts

Using a screwdriver and an adjustable wrench, tighten the bolts on your toilet tank. Don’t be frightened off by reports of toilet tanks cracking during household installs.

You’ll be able to set up a functional, crack-free toilet if you follow the guidelines below.

Using Rubber Washers

Take a rubber washer to set in the middle of the porcelain and the metal washer. When the bolt is tightened, the metal or plastic washer will be pressed against it. 

  • Rubber washers should be used everywhere a flat washer might come into contact with porcelain.
  • Inside the toilet tank, a rubber washer should be placed against the toilet tank’s bottom. On top of it was a metal flat washer, then followed by a bolt head.
  • Outside of the toilet tank, a rubber washer should be placed against the porcelain. After that, a metal washer is added and then tightens the bolt.

Rubber washers are required on the inside of the toilet tank and below the bowl flange. The tank and the bowl are connected through bolts. Fix them where they meet at the point. While tightening, this will protect the toilet tank. 

The rubber washers will bend a little when you tighten the screws. Take the strain off your toilet and keep it from cracking. If required, you can also change your toilet tank washer

Hand Tighten and Quarter Turn

After the washers are in place, thread the bolts into the toilet tank bolt sockets. Ensure you use your hands when tightening the bolts. Be careful to do this to all the tank bolts before continuing. 

Use a wrench to turn each bolt a quarter turn once they are finger-tight.

Once you’ve hand-tightened the bolts, you’re ready to go. Tighten each bolt a quarter-turn using an adjustable wrench or socket wrench. Tighten the wrench on the bolt and turn it 90 degrees to complete a quarter turn.

Bolts Are Not Needed To Be Too Tight

Bolts can be tightened enough with your hand and making a quarter-turn slightly. A toilet tank is meant to be light which is why it cannot not bear a lot of weight. 

Bolts are used to hold the rubber seal in place. The tank-to-bowl bolts need to be tight enough to be leak-proof.

The belief that the tighter the bolt, the better is one of the most common toilet installation mistakes. Do not follow this thinking and tighten it too much. Just keep it tight enough to keep it secure and leak-proof. 

Before Tightening, Further Check for Wobble

After tightening the tank with your hand and a quarter turn, check how secure the tank is. When it does not wobble, no need to tighten it more. If the tank wobbles significantly, ‌tighten it even more. 

Tighten the toilet bolt in smaller amounts after the first quarter turn.

Equally Tighten the Bolts

Working in little amounts and evenly tightening each bolt is required while tightening toilet tank bolts. You need to make sure you put the same force to tighten each bolt. If still the bolts keep spinning you need to change the bolts. 

It may take more time than necessary to tighten each bolt a little at a time. However, it does result in a flat, non-wobbling toilet tank.

Tighten bolts evenly in small amounts at all times. When the rubber washer’s shape is slightly changed from tightening, you can tell it is tight. Over-tightening a bolt raises the risk of your toilet cracking or forming a leaky seal. 

Inspect the Rubber Washer

When tightening the bolts, keep an eye out for the rubber washers inside and outside the toilet tank. When the rubber washers on both sides ‌deform, it’s time to cease tightening. If you twist the bolts any further, your toilet will crack.

If the bolts’ pressure has caused the washers to deform. It means you’ve over-tightened the bolts to the point of failure.

Observe for Leaks

Once you’ve equally tightened the bolts to create a hard, wobble-free seal, you’re usually done. But, it’s a good practice to observe over the next 24 hours. Keep an eye out for any leaks between the toilet tank and the bowl.

After installing it, if you see water around the toilet, it’s a sign of leakage. 

In case there is leakage in your toilet, bolts connect tank-to-bowl. After that, clean up any leaking water and keep an eye on it for the following 24 hours. When the toilet stops leaking, your task is done.

If not sure where the leakage is from, observe the source. Verify the leakage and tighten the tank bolts properly if required. 

Here is a recommended product which will help you with the installation:

Product 1

Normal for Toilet Tank to Wobble

It’s fine if the toilet tank wobbles a little. When the tank wobbles more than expected, a problem occurs. 

If the tank is wobbling, a loose bolt holding it to the bowl may be to blame. You’ll need to tighten them up a little bit in this scenario. They’ll be tough to remove if they’re too tight, and the tank may crack as a result.

Will Toilet Leak if Not Level

Even if the toilet isn’t level, most toilets in the home will work. If a toilet isn’t level and rocks, the wax seal and flange can be damaged quickly. It can cause the toilet to leak. When installing a toilet, it’s best to double-check if the toilet is level. 


Why are the tank bolts on my toilet leaking?

Misplaced or even cracked washers or bolts frequently cause a toilet to leak from its tank bolts. The bolts must either be tightened or replaced. A series of bolts normally connects the tank to the bowl on two-piece toilets.

What does a toilet with a 12 inch rough-in mean?

If you don’t know about the term “rough-in”, it refers to the location of the water exit. It’s usually found beneath the toilet. The true rough-in measurement is the distance between the center outlet and the back wall of your toilet.

Can the toilet tank touch the wall?

A toilet built against the wall is standard in most homes. It’s likely that a gap exists between your wall and the tank. Even if there’s no reason to be concerned, you should measure the gap’s length. It’s not a problem if the gap is below 2 inches.


We hope after reading this article now you know how tight toilet tank bolts should be. It’s now simple for you, and you may complete the installation on your own. 

Still, if you face any problem installing it, then call a professional before making it worse. 

Thank you for sticking with us and good luck with the installation!