I've encountered it in several places, mainly in public/hotel toilets, but also in my sister's old apartment, where people are asked to not throw anything (except for bodily waste) including toilet paper in to the toilet as it could cause a clog in the toilet bowl itself or the plumbing.

Throwing used toilet paper to a garbage bin that sits in the toilet always seemed disgusting to me, but there are people who do it due to fear of a clog. And the notion that tissue paper can cause a clog always seemed ridiculous to me as it seems that tissue paper dissolves and tears up in water really easily.

Can a normal amount of toilet paper used in one "sitting" made of tissue paper alone, together with bodily waste, cause a clog in a modern toilet/properly maintained plumbing?

Could it cause a clog in an old toilet or unmaintained plumbing?

Does this claim have any root in real cases that happened?

  • I'm talking only about tissue paper toilet paper, not about wipes, toilet towels or any other fabric or paper product that isn't made of tissue paper.

Related question: If I buy "flushable" wipes, can I flush them without problems?

  • use a lot and stamp it in it will become a soggy mess good for creating clogs, I had a friend who did that once... Apr 29, 2012 at 21:44
  • 3
    This could be very localised - in the UK, it is not very likely, due to the design of plumbing systems. In Greece, the majority of systems are not designed to cope with paper, so you may have major problems.
    – Rory Alsop
    Apr 29, 2012 at 23:04
  • 3
    No reference but from personal experience, yes toilet paper can clog a toilet. Apr 30, 2012 at 5:28
  • 1
    Why the down-votes?
    – SIMEL
    Apr 30, 2012 at 21:30
  • 1
    How much toilet paper? A leaf, a roll, a cartload?
    – Sklivvz
    May 1, 2012 at 8:44

1 Answer 1



Specifically, if tree roots are incurring the sewer pipes, toilet tissue can become snagged on the incurring roots and can cause a blockage. This is apparently one of the most common causes of blockages.

Tree root incursion is particularly bad in areas with cracked or porous ceramic pipes, where moisture and vapours can escape into the soil, which attracts and encourages growing tree roots.

The experts on this matter are plumbers, so let me quote one:

Once inside the pipe, tree roots will continue to grow and if not disturbed, they will completely fill the pipe with multiple hair-like root masses at each point of entry. The root mass inside the pipe becomes matted with grease, tissue paper, and other debris discharged from the residence or business.

There are some suitably gory images of sewer pipes showing root incursions on that site.

You should note that this is not the same reasoning for not flushing toilet paper in some other countries - plumbing systems need to be of an appropriate diameter, with pipes at specific angles and with few bends. If those criteria aren't met, flushing toilet paper can also cause a clog with or without any root incursion. An example of the fairly specific regulations for Orrville, Ohio (PDF) state:

All sanitary sewer service laterals from the main to the building may be vitrified clay pipe meeting ASTM C-700 material specification and ASTM C-425 joint specification or approved PVC pipe conforming to ASTM D3034 material specification and ASTM D 3212 joint specification. Said sanitary sewer shall be a minimum of six (6) inches in diameter and installed with a minimum slope of one (1) percent. Where an existing four (4) inch “Y” branch is found, and deemed serviceable by the City, the building sewer may be four (4) inches in diameter and installed with a minimum slope of two (2) percent.

These guidelines can vary from city to city, and depend on climate, types of pipes and fittings available, quality of mains water supply, and a host of other factors.

  • I apologise for the lack of references. If anyone can find an appropriate study on blocked sewer drains, I'd be appreciative.
    – John Lyon
    Apr 30, 2012 at 23:16
  • Technical manuals that are used by plumbers for training purposes should do the same trick.
    – rjzii
    Apr 30, 2012 at 23:35
  • @jazzas, Could you please extend on the second part of the answer, like when such guidelines where conceived, and if you can, at what countries/places those regulations are binding by law and where not.
    – SIMEL
    May 1, 2012 at 11:31
  • @Ilya that's not really relevant to your question, but I should add a reference anyway!
    – John Lyon
    May 1, 2012 at 11:57
  • @jozzas, I think that it's relevant, as the tree roots are a clog already in place not due to toilet paper. Sewer systems that can't handle toilet paper even in their maintained state are exactly what I was looking for.
    – SIMEL
    May 1, 2012 at 12:13

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