What Size Screws for Toilet Flange in Concrete? [Concrete Screw & Size]

what size screws for toilet flange in concrete

Typically, the screw size of the toilet flange for concrete or wood is similar. You will find out the difference between types of flange screw sizes for your toilet. So, what size screws for toilet flange in concrete?

According to my research, a toilet flange in concrete needs a 1/4″ x 2-1/2″ screw. I don’t tell you that it is a permanent size because different toilet flanges for concrete use different sizes. But, the 1/4″ x 2-1/2″ is the standard size for toilet flange in concrete.

Note that the concrete toilet flange needs strong screws which easily reach out to the holes in the concrete. So, it would help if you used the right size flange in concrete with strong build-in constructions.

How Do You Install a Toilet Flange on a Concrete Slab?

How Do You Install a Toilet Flange on a Concrete Slab

Image source: thespruce

Removing an old toilet and installing a new toilet is not tricky when following a frequent process. The flange for the toilet is a part of the toilet which helps the toilet attach to the floor.

From this section, you will get a complete solution to install a new toilet flange on a concrete slab so that you can hassle-free install it or guide your plumber to install the flange on concrete in the right way.

What Does Will need?

  • Hammer drill
  • Flange (I am using 1/4″ x 2-1/2″)
  • Putty knife
  • Tapecon screw
  • Tape measure
  • Screwdriver
  • Trash bag

Step 1: Cut Off the Old Flange

Before toilet flange screws to the floor, you need to cut off the old flange from your toilet. You will be able to cut the old flange after removing the old toilet. It is essential because of finding the floor flange properly.

Step 2: Clean Old Wax Ring

After removing the old flange, you should clean the wax ring. If you think that the old wax ring is damaged, it would be better for you to purchase a new one. I would love to suggest that you used scrab to clean the wax ring.

Step 3: Put T-Bolt in New Toilet Flange

Now, it is time to put the t-bolt in your new toilet flange. Here, you can use 1/4″ x 2-1/2″ t-bolt size. I am using two t-bolt screws inside the flange. You can use more t-bolt so that it would be more secure to use.

Step 4: Position Toilet Flange

Well, after putting the toilet flange t-bolt or screw, you need to ensure that both the t-bolt come with equal distance. Moreover, you should also measure the toilet flange and the toilet from the wall so that you can hassle-free assemble your new toilet.

Step 5: Drill Holes into the Concrete

With a hammer drill with a 1/4-inch concrete/masonry bit, you need to do 4-holes. You need to make the hole so that the screw easily passes, and the floor hole is never seen. I hope that you can understand whatever I said to you.

How to Remove a Toilet Flange in Concrete?

How to Remove a Toilet Flange in Concrete

It is a common question that wanted to know the removal process of a toilet flange in concrete. It is truly hard enough to remove a very old flange because the flange destroys like powder. However, you can check out the following process to easily remove toilet flange in concrete.

Step 1: Wear Safety Elements

First of all, you need to wear safety elements such as musk and gloves, and also protect your clothes because the old flange produces lots of dust, mud, and other harmful elements.

Step 2: Remove the Bolt or Screw

You can use a screwdriver to remove the bolt from the toilet flange in concrete. It may be hard enough for you. Well, you can also drop some oil on the bolt so that it can loose and easily be removed.

Step 3: Remove Flange

Now, it is time to remove the flange. If the flange destroys and makes powder, you should use sharp elements to properly cut down the removed flange. Here, it would help if you spent extra time properly removing the flange.

I hope that the above toilet flange installation diagram and removal process helps you to clear your concept of removing the flange. Do you have any questions or queries about this matter? You may let me know using the following comment box.

FAQs (Frequently Ask Questions)

Q: What screws for toilet flange in concrete?

Answer: You can use Tapcon anchors or a similar type of masonry/concrete screw or metal body screw for your toilet flange in concrete. Note, the Tapcon anchor screws are much more popular for toilet flange in concrete than others.

Q: How do you screw a toilet flange into concrete?

Answer: You need to use some tools and a proper guideline to screw your toilet flange into concrete. As your helping hand, I already have done a simple method in the above article so that you can hassle-free screw your toilet flange into concrete.

Q: Does a toilet flange need to be screwed to the floor?

Answer: Of course, it is essential to screw the toilet flange with the floor. Why? Because the toilet flange securely anchors with the floor and your toilet becomes safe to move when you are using the toilet.

Q: What are concrete screws?

Answer: The concrete screw is a special thread screw that comes with so hard and strong build-in construction. The concrete screws are used for concrete floors and other concrete areas. Most of the concrete screws come in a small size than the diameter of the screw.


According to my toilet flange in concrete installation experience, 1/4″ x 2-1/2″ screw size is enough for a toilet flange in concrete. Moreover, it is also important to use strong concrete screws such as Tapcon and other screws which easily put on the concrete and never destroy the concrete.

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