How Tight Should Toilet Tank Bolts Be?

Your toilet is one of the most important but least thought-of features in your home. It is used every day but not thought about because it is expected to work. For it to keep working well, though, it should be installed and maintained the right way.

One overlooked area of your toilet installation is probably the toilet tank bolts. Most people wonder how tight toilet tank bolts should be and how to tighten toilet tank bolts.

toilet tank bolts

So, how tight should toilet tank bolts be? They don’t have to be extremely tight, but you also must remember that they are there to ensure that the rubber gasket and seal are snug and leakproof and you don’t find yourself with a loose toilet.

Read on to learn more about tightening bolts and what you should expect.

What Is the Best Way to Tighten Toilet Tank Bolts?

The best way to tighten toilet tank bolts is to hand-tighten the nuts on the tank bolts and then switch to using a wrench to make a quarter-turn on each nut and get them tight. They should be tight enough that you don’t have a wobbly toilet or leak, and if the tank seems loose at all or toilet leaking becomes a problem, you should continue tightening the toilet tank bolts because they are not tight enough.

Tightening Your Toilet Tank Bolts

The toilet tank bolts on your toilet aren’t something you need to worry about every day. Your toilet will function perfectly fine if you never touch them after the installation and the toilet is not wobbling or shifting at all.

Still, you should pay special care to the tightening of the toilet tank bolts because this will determine if the tank can seal water inside the tank and ensure that with many years of use, your toilet does not crack with differential stress.

The toilet tank bolts keep your toilet secure but also balanced, distributing the weight of a typically heavy porcelain toilet to the stress points designated by the manufacturer. If the toilet tank bolts are not tight enough or are not tightened properly, the toilet may wobble.

The weight of the toilet can also shift, causing stress unevenly or in places not intended to bear that kind of weight as designated by the manufacturer.

If toilet tank bolt head is overtightened, you run the risk of cracking your porcelain toilet bowl and causing a leak. The toilet leak can be a slow leak or something more serious like a full water leak. So, make sure the bolts are snug but not too tight.

How to Tighten Toilet Tank Bolts

To give your toilet a fighting chance at lasting years and possibly decades with the right care, you should tighten the toilet tank bolts as best as possible from the beginning.


Turn off the water supply line.


Remove the lid from the top of the tank.


Push and hold down the flush lever. This will empty the tank completely, but the tank might need a little time to empty completely. When the tank is empty, you can release the lever, and it should remain empty because the water supply line has been turned off, and it will not be able to refill the tank.


Slide the end of a screwdriver into the head of one of the tank mounting bolts on the inside of the tank. Next, grab the nut of that bolt with an adjustable wrench, and turn the screwdriver with the bolt two full revolutions clockwise. Keep doing this with the first and second tank mounting bolts until the process is complete and the toilet tank bolts are secure.


Turn on the water supply line. Allow the tank to fill and inspect the bottom of the tank after an hour. The tank and the floor around it should be dry.

Once the toilet tank bolts are in place, your toilet should be good to go. However, there are some things to know about your toilet tank bolts that could affect the functioning and lifespan of your toilet.

Can Toilet Tank Bolts Be Too Tight?

If the toilet tank bolts are too tight, they could crack the toilet tank or the bowl. Porcelain is very hard but can be prone to cracking, and an over-tightened bolt will crack the ceramic.

Hand-Tighten Your Bolts

Using your hand to thread the nuts onto the toilet tank bolts and tighten will allow you to feel the pressure and stress of the bolt. If it feels too tight, move slower or stop turning altogether. When using the adjustable wrench, use small, short, quarter-turns to not over tighten the bolt and crack the toilet tank or the toilet bowl.

How Do You Know If It Is Tight Enough?

Despite what most might think and what might feel best at the moment, toilet tanks are not intended to take very much weight and strain. They are strong and can often be quite heavy, but the porcelain can crack with the wrong amount and type of pressure or strain.

The bolts are there to ensure the rubber seal between the tank and bowl is snug and leakproof, but it does not have to be super tight to achieve water tightness. These are not strain-bearing bolts and are only meant to plug the holes and keep the water in the tank.

How Do You Stop a Toilet Tank from Wobbling?

If you’re not sure how much to tighten or you’re worried you haven’t tightened the toilet tank bolts enough, check for a wobble on the toilet. If the tank does not wobble after the first tightening, there is no need to continue tightening the bolts. The function of the bolts is to keep the toilet tank from wobbling and the water from leaking onto the floor.

If these two goals are met, your plumbing job is done. However, if you have a rocking toilet, you can continue to tighten the bolts but use small increments, possibly under a quarter-turn each time, while checking each time between cranks.

An Unsung Hero

Rarely thought of but missed when not functioning properly, the toilet tank bolt is the unsung hero of the toilet. Get the tightening of the toilet bolt right the first time with these steps, and you will avoid many headaches down the road with the long-term care of your toilet.

Frequently Asked Questions (FAQ)

How much should you tighten toilet tank bolts?

You should tighten them as much as needed to keep the tank from wobbling and the water from leaking. Beyond this, there is no need to keep tightening as this is sure to bring issues either immediately or down the line with further use of the toilet.

How do I know it’s enough tightening?

Check the bolts each time after the initial tightening, and if it wobbles, you can tighten the bolts in small increments. If it doesn’t wobble, there is no need to keep tightening.

How can I test the bolts further?

To really make sure the bolts are secure, test your toilet under normal use and conditions for 12-24 hours. If the tank is leaking, you should tighten the bolts again using the steps listed above. If not, then you can rest assured you have installed the tank well.

How do you loosen the bolts on a toilet tank?

To loosen the bolts on a toilet tank, get a flat head screwdriver and a wrench. The screwdriver can be used to hold the bolt in place while you use the wrench over the nut located under the tank. Then, turn it counterclockwise to loosen the bolts.

What if there is a rusted bolt?

Whether you have a rusted bolt or not, the first step to removing the bolt is a flat head screwdriver and a wrench. Remove the plastic cap over the stuck or rusted bolt, loosen the nut as much as you can and use a wrench or socket set to turn the nut counterclockwise.

Leave a Comment

Your email address will not be published. Required fields are marked *