15 Top Mistakes Tradespeople Make

Whether it’s a sparky, a plumber, landscape gardener or your regular builder, there’s no trade immune from on-the-job blunders. Newbie tradesmen can arguably be forgiven for forgetting the rules but old hands should know better. Here are our top 15 mistakes that tradesmen should avoid.

Electrical settings

A common mistake many electricians make at some stage is using a digital meter on an incorrect setting: AC instead of DC, ohms instead of voltage, or checking a high voltage range with a lower range volt-meter. All these can leave the sparky momentarily baffled, or worse, cause a painful accident.

Electrical safety


Plumbing – Incorrect drain slope

Even an amateur can guess why it’s important that drains slope downhill. Properly draining away into the sewers is what pipes should be doing, but it’s an exact science because if it’s a fraction out in either direction, you’re in danger of either an under-slope or an over-slope. The best plumbers have it down to an art.

Safety first

Many electricians will tell you their biggest fear is accidentally working on a live current. Presume the current is always live and double-check that everything is disconnected and locked off. Trusting the labels is not a good idea as changes to voltage may not be noted.

Electrical Fuze Box


Last-minute changes

Whether it’s the architect, contractor or builder, making a sudden change after plans are finalised – such as moving a door or window – can invite a whole new set of problems. For example, being forced to move an integral beam support could leave you with one very unhappy engineer, not to mention extra costs.

Cutting corners

Contractors risk running into problems when it comes to cutting corners on a project, but one of the most costly mistakes they can make is cutting corners on public liability insurance. It can seem an easy way to keep costs down at the start of a project but any on-site accident or injury could end up costing a whole lot more, not to mention the reputational damage that could ensue.


Public Liability Insurance

Building agreements

Often mistakes are made due to unclear terms as to what is to be done. An agreement between builder and owner should be clear and detailed from the beginning. Not specifying the build from the beginning means you’re inviting hidden costs, causing construction to take longer than planned. In a worst-case scenario, the contractor may abandon a messy project in favour of a more lucrative one.

Building wrapping

It’s safe to assume rain is always a probability when working on a building site in Ireland. Incorrectly ‘wrapping’ the building at the end of the day can let water and damp in, and lead to mould and rotting wood. A tarp thrown over with a few bricks holding it down is a sure sign of a cowboy builder. Seams should be overlapped and properly sealed to make a weather-tight bond.

Floor plans

Lack of foresight in designing a floor plan will quickly become apparent when no sunlight streams into the main rooms, or the windows miss the main vista entirely. Even a quick recce of the site will help spot these.

Beautiful living room


Skipping the prep

Most professional painters would never dream of skipping the prep before a painting job but some newbies are eager to start and get the job done fast. Lack of time spent on cleaning and prepping the walls around cracks and dents, results in shoddy workmanship.

Not clearing the room

A little bit of paint goes a long way. The best painters ensure they have cleared all the furniture, light fixtures and hardware before getting to work. Drywall dust will seek out every nook and cranny, and flecks of paint will find their way onto every surface, so no chances can be taken.

Lack of planning

All contractors should work from a sound structural and design plan. When installing anything from scratch, a contractor, builder, engineer should think of all eventualities and not just the job at hand. For instance, will routing pipes in a certain way lead to unnecessary noise when the toilets are flushed? Or do these cupboards leave room for the planned top-loading laundry machine underneath? Functionality is key.

Over-ambitious gardens

Landscape gardeners love their work. Give them enough scope and they will come back with lofty plans. This is great of course, and why they’re being paid, but often the client is left with a beautiful garden they have neither the time nor skills to maintain. Soon it turns into a jungle, avoided by all. Sometimes simplicity is best.


Mismatched plumbing

Sometimes plumbers discover they have the wrong pipe or plumbing fixture for the job. Maybe it’s just a small job they want to finish quickly. An unscrupulous plumber may push on and use the dud part anyway, which could lead to corrosion or disastrous plumbing problems later on.


Another mistake landscape gardeners make is not accounting for wildlife. The wildlife don’t care how precious the design is, and will colonise the garden, regardless. You may invite in some unwanted animals by planting non-native plants, or worse, you may end up repelling birds or insects that are vital for the garden to thrive.

Hiring unskilled labourers

Tradesmen may be pitching for a job against other builders and contractors so it can be tempting to keep costs down. One way to do this is by hiring unskilled or inexperienced labourers. This might make the quote look good but will result in shoddy work, with the builder carrying these workers through the project and picking up the slack on errors. If the quote seems too good to be true, it probably is.