Difference between revisions of "Unblock a Drain"

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[[image:Drain rods 5969-2.jpg|600px]]
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There are many ways to unblock drains. Always act before the blockage is total, as a total block makes getting chemicals to the blockage difficult to impractical.
 
There are many ways to unblock drains. Always act before the blockage is total, as a total block makes getting chemicals to the blockage difficult to impractical.
  
  
 
=The Blockage=
 
=The Blockage=
 +
[[image:Drain blockage 4029-3.jpg|right|150px]]
 +
 
#The most common drain blocking material is fat, which can be cleared by caustic soda, rodding, or physical removal with hand or sticks.  
 
#The most common drain blocking material is fat, which can be cleared by caustic soda, rodding, or physical removal with hand or sticks.  
 
#The next most common blocker is hair and matted fibres, which can be tackled with strong acids, physical removal or sometimes a plunger.  
 
#The next most common blocker is hair and matted fibres, which can be tackled with strong acids, physical removal or sometimes a plunger.  
Line 12: Line 16:
  
  
==Boiling water==
+
=Unblocking=
Not the most effective, but sometimes unblocks fat blockages. Can be tried if nothing else is to hand. Fat dissolving chemicals should then be used to clear the drain properly. The more boiling water is used, the longer it stays hot and the more chance it has of melting through the blockage.
+
Which to try first?
 +
# Caustic soda
 +
# Rodding
 +
# Sulphuric acid is an option, works well but can do damage
 +
# Lots of boiling water can be tried if none of the above are to hand, it fairly often works.
  
=Chemicals=
+
Sink waste pipes can usually be rodded with a handheld wire unblocker, 2mm iron wire or fish tape.
==Sulphuric acid==
 
Eats organic material, eg turd & paper. Also eats limescale, which is sometimes part of a blockage.
 
  
* Dont't mix acid with alkali.
+
==Heat==
* Keep strong acids off chromework.
+
===Boiling water===
 
+
Not the most effective, but sometimes unblocks fat blockages. Can be tried if nothing else is to hand. Fat dissolving chemicals should then be used to clear the drain properly. The more boiling water is used, the longer it stays hot and the more chance it has of melting through the blockage.
 
 
==Hydrochloric acid==
 
[[image:HCl 2541-2.jpg|thumb]]
 
 
 
Eats organic material & limescale. More aggressive than sulphuric acid. A relatively high risk chemical.
 
 
 
30% hydrochloric acid is sold as brick acid. Some patio cleaners contain HCl.
 
 
 
* Never mix a strong acid with an alkali
 
* Never mix acid with bleach
 
* Protect eyes from HCl
 
* Keep strong acids off chromework
 
  
==Caustic soda==
+
==Chemicals==
[[image:Caustic soda 2526-2.jpg|thumb]]
+
===Caustic soda===
 +
[[image:Caustic soda 2526-2.jpg|thumb|Mystery chemical]]
  
Caustic eats fats, which are the most common blocker of kitchen sinks. Boiling caustic is much faster than cold caustic.
+
Caustic is a good first chemical to use, as it eats the most common blocking materials and doesn't attack the drain itself. It eats fats, which are the most common blocker of kitchen sinks. Boiling caustic is much faster than cold caustic.
  
 
Caustic is a high risk chemical. It burns skin and can cause serious eye damage. If you get any at all in your eye, it is important to seek treatment urgently. Delay in treatment (it doesn't hurt) generally results in serious irreversible damage.
 
Caustic is a high risk chemical. It burns skin and can cause serious eye damage. If you get any at all in your eye, it is important to seek treatment urgently. Delay in treatment (it doesn't hurt) generally results in serious irreversible damage.
Line 50: Line 45:
 
Washing soda and baking soda are much weaker, and usually inadequate.
 
Washing soda and baking soda are much weaker, and usually inadequate.
  
==Bio-enzymes==
+
===Sulphuric acid===
These eat biological matter, but can take a long time to do so. Also unlikely to survive being added to a drain full of caustic or acid.
+
[[image:H2SO4 98% 4170-3.jpg|thumb|98% Sulphuric acid]]
 +
 
 +
Sulphuric is usually the 2nd choice unblocking chemical. Its effective, but attacks cement drain joints.
 +
 
 +
* Eats organic material, eg turd & paper
 +
* Eats limescale
 +
* Very aggressive
 +
* A high risk chemical
 +
* Wear eye protection or a full face shield
 +
* Dont't mix acid with alkali.
 +
* Don't pour water into acid
 +
* Keep strong acids off chromework.
 +
* When using strong acid, its advisable to flush the loo a few times afterwards, in case the sewage piping contains [[metal]] or [[mortar]]ed pipework, which acids attack.
  
=Mechanical=
+
===Hydrochloric acid===
==Rod==
+
[[image:HCl 34% 4168-3.jpg|thumb|34% Hydrochloric acid]]
Very effective mechanical unblocker. The most bulky and expensive option.
+
* Eats organic material
 +
* Eats limescale.
 +
* A relatively high risk chemical.
 +
* 30% hydrochloric acid is sold as brick acid. Some patio cleaners contain a lower level of HCl.
 +
* Attacks cement drain joints
 +
* Never mix a strong acid with an alkali
 +
* Never mix acid with bleach
 +
* Don't pour water into acid
 +
* Protect eyes from HCl
 +
* Keep strong acids off chromework
 +
* When using strong acid, its advisable to flush the loo a few times afterwards, in case the sewage piping contains [[metal]] or [[mortar]]ed pipework, which acids attack.
  
 +
===Bio-enzymes===
 +
These eat biological matter, but can take a very long time to do so. Also unlikely to survive being added to a drain full of caustic or acid. Too slow for drain unblocking.
  
==Metal tape==
+
 
 +
==Mechanical==
 +
===Rod===
 +
The most effective mechanical unblocker. Use when other measures have failed. Drain rods are £15-20 a set in 2012.
 +
 
 +
===Metal tape/wire===
 
A reel of flexible metal strip or tape makes a low cost & physically small rodding device. Also sold in rotating containers for greater effectiveness.
 
A reel of flexible metal strip or tape makes a low cost & physically small rodding device. Also sold in rotating containers for greater effectiveness.
  
 
+
===Wire===
==Wire==
 
 
2mm [[Iron wire]] is enough to remove many types of blockage. Cost is minimal, and its already to hand in many cases. An advantage of iron wire is it can be fed in through a 5mm hole, which are easily made anywhere in plastic drain pipe.
 
2mm [[Iron wire]] is enough to remove many types of blockage. Cost is minimal, and its already to hand in many cases. An advantage of iron wire is it can be fed in through a 5mm hole, which are easily made anywhere in plastic drain pipe.
  
Line 71: Line 94:
 
3mm coathanger wire is much too stiff and behaves badly. 1.6mm wire is much too flexible, and 1mm wire is useless.
 
3mm coathanger wire is much too stiff and behaves badly. 1.6mm wire is much too flexible, and 1mm wire is useless.
  
==Plunger==
+
===Plunger===
 
Block all other airholes, eg overflow. Push plunger down gently but firmly, and pull up with force. Good for sinks where the blockage is an accumulation of small pieces, eg food.
 
Block all other airholes, eg overflow. Push plunger down gently but firmly, and pull up with force. Good for sinks where the blockage is an accumulation of small pieces, eg food.
  
 
+
===Hose===
==Hose==
 
 
Insert hose down drain. Block all holes with towel. Turn hose on full blast. Prepare to get wet and make a mess. Works on soft blockages, but messy.
 
Insert hose down drain. Block all holes with towel. Turn hose on full blast. Prepare to get wet and make a mess. Works on soft blockages, but messy.
  
 
+
===Pressure Washer===
==Pressure Washer==
 
 
Can unblock drains, but very messy, and unblocking sewage creates disgustification and a health hazard. For sewage, full splash protection is desirable, but it won't keep you clean & dry.
 
Can unblock drains, but very messy, and unblocking sewage creates disgustification and a health hazard. For sewage, full splash protection is desirable, but it won't keep you clean & dry.
  
 
Outdoor blockages only.
 
Outdoor blockages only.
  
 +
===Curtain Wire===
 +
Curtain wire can be used for clearing blockages close to access points. A metal wire/tape tool is better, with much greater reach.
  
==Curtain Wire==
 
Curtain wire can be used for clearing blockages close to access points. A metal tape tool is better, with much greater reach.
 
  
 
+
==Cleaning points==
=Cleaning points=
+
===Plugholes===
==Plugholes==
 
 
Some sink/basin plugholes have a built in strainer, sometimes this just needs to be lifted out and cleaned.
 
Some sink/basin plugholes have a built in strainer, sometimes this just needs to be lifted out and cleaned.
  
==Traps==
+
===Traps===
 
Waste traps fitted under sinks, basins, baths and showers can be disassembled to empty the accumulated crud, and allow rodding access to the pipe. There are a few different styles of trap, but all unscrew by hand, or if stiff with gentle use of a wrench.
 
Waste traps fitted under sinks, basins, baths and showers can be disassembled to empty the accumulated crud, and allow rodding access to the pipe. There are a few different styles of trap, but all unscrew by hand, or if stiff with gentle use of a wrench.
  
==Filters==
+
===Filters===
 
Some washing machines have a cleanable filter at the bottom on the front.
 
Some washing machines have a cleanable filter at the bottom on the front.
  
=Rodding Access points=
+
==Rodding Access points==
  
==Rodding eyes==
+
===Rodding eyes===
  
==Drain covers==
+
===Drain covers===
  
==Open pipe ends==
+
===Open pipe ends===
  
==Re-assemblable joints==
+
===Re-assemblable joints===
 
Compression and some pushfit joints can be disassembled and reassembled. Disassembly is impossible with solvent welded pipe, the parts fuse to make one solid piece of plastic.
 
Compression and some pushfit joints can be disassembled and reassembled. Disassembly is impossible with solvent welded pipe, the parts fuse to make one solid piece of plastic.
  
==Drilled hole==
+
===Drilled hole===
 
[[image:Waste pipe hole repair 2401-2.jpg|thumb|access hole resealed]]
 
[[image:Waste pipe hole repair 2401-2.jpg|thumb|access hole resealed]]
  
 
A 5mm hole allows a 2mm [[iron wire]] to pass inside the pipe. This is useful for solvent weld pipework with no means of access. A 5mm hole is [[drill bit|drilled]], and capped after use with either  
 
A 5mm hole allows a 2mm [[iron wire]] to pass inside the pipe. This is useful for solvent weld pipework with no means of access. A 5mm hole is [[drill bit|drilled]], and capped after use with either  
 
* a piece of plastic pipe and some pipe weld solvent, or
 
* a piece of plastic pipe and some pipe weld solvent, or
* a rubber washer, a bent metal washer and a cable tie
+
* a rubber washer, a bent metal washer and a cable tie (pictured)
* a short screw
+
* a short [[screw]]
* piece of plastic, silicone, cable tie
+
* piece of [[plastic]], silicone, cable tie
 +
 
  
=See Also=
+
==See Also==
 
* [[Special:Allpages|Wiki Contents]]
 
* [[Special:Allpages|Wiki Contents]]
 
* [[Special:Categories|Wiki Subject Categories]]
 
* [[Special:Categories|Wiki Subject Categories]]
Line 128: Line 149:
 
[[Category:Bathrooms]]
 
[[Category:Bathrooms]]
 
[[Category:Kitchens]]
 
[[Category:Kitchens]]
 +
[[Category:Chemicals]]
 +
[[Category:Repair]]
 +
[[Category:Basics]]

Latest revision as of 23:52, 14 November 2012

Drain rods 5969-2.jpg

There are many ways to unblock drains. Always act before the blockage is total, as a total block makes getting chemicals to the blockage difficult to impractical.


The Blockage

Drain blockage 4029-3.jpg
  1. The most common drain blocking material is fat, which can be cleared by caustic soda, rodding, or physical removal with hand or sticks.
  2. The next most common blocker is hair and matted fibres, which can be tackled with strong acids, physical removal or sometimes a plunger.
  3. Soft foods can also block drains sometimes, these can be tackled by scooping out, rodding, use of a wire and sometimes a plunger. If just partially broken up in situ to allow water to pass, the remainder decomposes and clears itself over the weeks ahead.
  4. Leaves can block open outdoor drains, both at ground level and in elevated hoppers. Best scooped out by hand.
  5. The least common drain blocker is limescale, which responds to long immersion times with acids, or if accessible and in a strong concrete drain, it can often be chiselled off. A needle drill is also effective on scale, but few DIYers have one.

Blockage by solid items can also occur, most often toilet rim blocks, and sometimes plastic toys. No chemical will dissolve these, they must be removed.


Unblocking

Which to try first?

  1. Caustic soda
  2. Rodding
  3. Sulphuric acid is an option, works well but can do damage
  4. Lots of boiling water can be tried if none of the above are to hand, it fairly often works.

Sink waste pipes can usually be rodded with a handheld wire unblocker, 2mm iron wire or fish tape.

Heat

Boiling water

Not the most effective, but sometimes unblocks fat blockages. Can be tried if nothing else is to hand. Fat dissolving chemicals should then be used to clear the drain properly. The more boiling water is used, the longer it stays hot and the more chance it has of melting through the blockage.

Chemicals

Caustic soda

Mystery chemical

Caustic is a good first chemical to use, as it eats the most common blocking materials and doesn't attack the drain itself. It eats fats, which are the most common blocker of kitchen sinks. Boiling caustic is much faster than cold caustic.

Caustic is a high risk chemical. It burns skin and can cause serious eye damage. If you get any at all in your eye, it is important to seek treatment urgently. Delay in treatment (it doesn't hurt) generally results in serious irreversible damage.

Preparing boiling caustic solution sprays strong alkali droplets, and thorough eye protection is essential.

  • Caustic soda is a strong alkali.
  • Never mix a strong alkali with an acid.
  • Eye protection needed

Washing soda and baking soda are much weaker, and usually inadequate.

Sulphuric acid

98% Sulphuric acid

Sulphuric is usually the 2nd choice unblocking chemical. Its effective, but attacks cement drain joints.

  • Eats organic material, eg turd & paper
  • Eats limescale
  • Very aggressive
  • A high risk chemical
  • Wear eye protection or a full face shield
  • Dont't mix acid with alkali.
  • Don't pour water into acid
  • Keep strong acids off chromework.
  • When using strong acid, its advisable to flush the loo a few times afterwards, in case the sewage piping contains metal or mortared pipework, which acids attack.

Hydrochloric acid

34% Hydrochloric acid
  • Eats organic material
  • Eats limescale.
  • A relatively high risk chemical.
  • 30% hydrochloric acid is sold as brick acid. Some patio cleaners contain a lower level of HCl.
  • Attacks cement drain joints
  • Never mix a strong acid with an alkali
  • Never mix acid with bleach
  • Don't pour water into acid
  • Protect eyes from HCl
  • Keep strong acids off chromework
  • When using strong acid, its advisable to flush the loo a few times afterwards, in case the sewage piping contains metal or mortared pipework, which acids attack.

Bio-enzymes

These eat biological matter, but can take a very long time to do so. Also unlikely to survive being added to a drain full of caustic or acid. Too slow for drain unblocking.


Mechanical

Rod

The most effective mechanical unblocker. Use when other measures have failed. Drain rods are £15-20 a set in 2012.

Metal tape/wire

A reel of flexible metal strip or tape makes a low cost & physically small rodding device. Also sold in rotating containers for greater effectiveness.

Wire

2mm Iron wire is enough to remove many types of blockage. Cost is minimal, and its already to hand in many cases. An advantage of iron wire is it can be fed in through a 5mm hole, which are easily made anywhere in plastic drain pipe.

Wire does not generally clear a drain fully, but makes a passageway for water. The remainder of the blockage should then be cleared with a suitable chemical.

2mm wire has minimal ability to go round corners, its only good for very short distance rodding.

3mm coathanger wire is much too stiff and behaves badly. 1.6mm wire is much too flexible, and 1mm wire is useless.

Plunger

Block all other airholes, eg overflow. Push plunger down gently but firmly, and pull up with force. Good for sinks where the blockage is an accumulation of small pieces, eg food.

Hose

Insert hose down drain. Block all holes with towel. Turn hose on full blast. Prepare to get wet and make a mess. Works on soft blockages, but messy.

Pressure Washer

Can unblock drains, but very messy, and unblocking sewage creates disgustification and a health hazard. For sewage, full splash protection is desirable, but it won't keep you clean & dry.

Outdoor blockages only.

Curtain Wire

Curtain wire can be used for clearing blockages close to access points. A metal wire/tape tool is better, with much greater reach.


Cleaning points

Plugholes

Some sink/basin plugholes have a built in strainer, sometimes this just needs to be lifted out and cleaned.

Traps

Waste traps fitted under sinks, basins, baths and showers can be disassembled to empty the accumulated crud, and allow rodding access to the pipe. There are a few different styles of trap, but all unscrew by hand, or if stiff with gentle use of a wrench.

Filters

Some washing machines have a cleanable filter at the bottom on the front.

Rodding Access points

Rodding eyes

Drain covers

Open pipe ends

Re-assemblable joints

Compression and some pushfit joints can be disassembled and reassembled. Disassembly is impossible with solvent welded pipe, the parts fuse to make one solid piece of plastic.

Drilled hole

access hole resealed

A 5mm hole allows a 2mm iron wire to pass inside the pipe. This is useful for solvent weld pipework with no means of access. A 5mm hole is drilled, and capped after use with either

  • a piece of plastic pipe and some pipe weld solvent, or
  • a rubber washer, a bent metal washer and a cable tie (pictured)
  • a short screw
  • piece of plastic, silicone, cable tie


See Also