How to Identify DIY Plumbing in a House You’re About to Purchase

DIY Plumbing in a property you'e about to purchase

DIY Plumbing is still going on behind closed doors. Plumbers are finding these poor installations as soon as they arrive at a job and share them on social media to show what they need to fix. Last year I shared some common ways illegal plumbing can be identified during a plumbing inspection and I want to share these with you here if you are planning to purchase a property.

While the terrible installations shared on social media can make us laugh and shake our head, the issue is people still believe they can do their own plumbing and get away with it.

Sometimes they do get away with it, but most times it will be caught out. The purpose of this post is to equip you on what to look for and what you can do to prevent yourself purchasing a home that requires extensive plumbing work to get fixed.

The conveyancer can pick up abnormalities from plans when they check for certification on bathrooms and kitchens. There are some checks the conveyancer won’t pick up though which will be identified in person. This is why inspections on site are paramount to ensure you know what you’re buying.

Here are the key areas you need to check for yourself when identifying DIY plumbing in a property you’re about to purchase.

1. If it doesn’t look right, it’s probably not

If you see pipes at an odd angle, fittings that look unusual, back fall, unusual spaces between taps and fixtures or fittings that have been installed twice or connection upon connection – like this classic toilet, it’s most likely been done by someone without a plumbing license.


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A post shared by Tscplumb (@plumblife27)

2. Bad Silicone Job

Applying silicone neatly is a skill in itself. If there is silicone smeared all around a toilet waste, shower cubicle, sink waste or on pipes underneath a house, you know the job has been done by someone who didn’t want to get a plumber involved. Silicone can provide an additional seal but is only used as a temporary fix. Most plumbers will use it sparingly and certainly won’t smear it like a dog’s breakfast.

bad silicone job

3. Flex hoses connected like skipping ropes

Flex hoses are a common connection for taps and toilets. They do have their headaches and require to be checked regularly for rust or fraying to avoid a blowout. If you see flex hoses connected like a skipping rope, you know DIY plumbing has taken place. They aren’t mean to be joined together to create long water lines or used to connect a hot water unit. If you see too many flex hoses connected together, that should raise an alarm that DIY plumbing has taken place.

Unfortunately you won’t know what is behind the walls of your property, but for the sake of explaining what to look for on exposed water pipes, this photo from Flow Plumbing Drainage & Gas Fitting Pty Ltd shows what you don’t want to see with your flex hoses.


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This is not how to rough in a shower mixer. #crapplumbing #flexihookerseverywhere

A post shared by Plumber 💦 Drainer 🔥 Gas Fitter (@flowpdg) on


4. Too Much Glue

PVC pipe and fittings are connected with glue and primer. This seal allows for the PVC pipe and fittings to weld together. Most often, PVC pipe that has glue and little evidence of priming could be a sign of DIY Plumbing.


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#mates #matesrates #crapplumbing #perthplumbers

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5. Piggybacked PVC Fittings

Waste and sewer connections require skill in using minimal connectors and bends to create a neat pipework installation that has the correct fall. When you see multiple connections piggybacked together, it’s a sign DIY Plumbing or a really bad plumbing installation has taken place.

6. Wrong Sized Pipe Connections

Another sign is seeing a 50mm pipe connected through the floor into a 40mm pipe. This is not only illegal it’s not even standard practice. Dad and I once went to a house where a 50mm sink waste was connected to a 40mm waist through the cupboard. The owner advised his brother-in-law who was ‘handy’ helped him install it. No chance of that house selling till the work would be rectified.

7. Duct Tape Everywhere

Duct tape can fix many things, but plumbing is not one of them (although many will give it a red hot go!). If you see duct tape holding up a fixture or wrapped around a pipe, it may be concealing a bigger plumbing problem the owners need to fix.


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Ummm #plumbing #plumber #plumbers #plumblife #crapplumbing

A post shared by Crap Plumbing ( on


8. Water and Waste flowing through the wrong channels.

Sewerage connected to a storm water drain is a big sign of DIY Plumbing taking place. It’s important for a plumber to make the right connections. This one is little bit harder to identify, but your licensed plumber should be able to inspect with a drain camera to ensure the right waste is going down the correct channels.

9. Hot and Cold Water on the wrong side

Hot should be on the left and cold should be on the right. When you turn the taps on, the right temperature water should flow through. A building inspector will pick up this basic defect. It can be an easy fix, providing the water pipes are accessible under the vanity or in the wall.

10. Water builds up in in the drain when the tap is turned on

If the basin fills up when the tap is turned on, there is a potential blockage. If all the fixtures back up with water, there is most likely a blockage on the main sewer. This could lead to a bigger problem like tree roots. This can require considerable cost to fix. This is a property maintenance issue rather than a DIY Plumbing issue.

For renovated bathrooms, if the water flows down the shower slowly, there could be tiler’s grout stuck down the waste. Always turn the water on fixtures in the home to see how easily the water flows down the drain.

Many DIY plumbing fails will be identified by a licensed plumber. While it’s recommended to get a building and pest inspection before the sale of a property goes unconditional, it’s just as important to get a plumbing inspection. The plumber can also check the drains with a drain camera and their report can give you peace of mind about the property you’re about to purchase.

Plumbing is an expensive area to fix if it’s been done incorrectly. Save yourself the financial disappointment of fixing work that was covered up by the previous owners by booking a plumbing inspection.

What other DIY Plumbing fails have you found in a property, not mentioned here?