The big masking tape no-no – and 9 more painting mistakes to avoid

It might be tempting to skip the preparation stage as it can take longer than you think to get a room ready for painting. If you need to fill, sand or prime the walls or woodwork, for example, it can be tempting to do a rush job and move on to the fun bit.

But it can be a false economy as you end up having to redo areas or realise halfway through painting the walls that you really should have paid more attention to the preparation at the beginning.

Rob Green, co-founder at Coat Paints, says: “Don’t skip the prep. Wiping down and sanding surfaces before painting can feel like a chore, but if you want a perfectly smooth and super tough surface for years – get rid of the grime first.”

A painting mistake many make is not priming walls before applying the topcoat.“Priming creates a stable and porous surface for the paint to adhere to,” says Pav Wąsik, founder of Uptown Interiors

“It provides a bonding layer between the substrate (such as drywall, wood or previously painted surfaces) and the paint. This enhanced adhesion helps the paint to adhere more securely, reducing the chances of peeling, chipping or flaking over time.”

Priming walls for painting can also help create a more even finish. “Different materials have varying levels of porosity, which can cause uneven absorption of paint,” explains Wąsik. “Priming helps to regulate the surface absorption by sealing porous areas and creating a consistent base. This ensures that the paint dries uniformly, resulting in a more even and professional-looking finish.”

One painting mistake to avoid is not having enough paint. “Working out the exact amount of paint you need isn’t just down to the space, it’s also dependent on the quality of paint and can be specific to the brand,” says Emma Bestley, co-founder and creative director of YesColours.

“To know how much paint you will need, simply measure the length and height of the space, then multiply the figures together and you will have the square metre total. For the whole room, we suggest measuring each wall this way and then adding them together.”

Lots of paint companies have handy paint calculators on their websites. You simply type in the height and length of your walls and the calculator will add up how much paint you will need.

Paint is made up of a combination of liquids and solids and, over time, will separate. If you don’t stir the paint before using it, you’ll find that it’ll be thin and watery or thick and gloopy, which will give you an uneven, patchy paint job.

Stirring paint before you use it will mix the liquids and solids back together, forming a more uniform consistency and colour. This applies to a new tin or a tin of paint you’re reopening. Do use a paint stirrer – they are made for the job because the holes down the length of the stirrer help the paint mix and flow evenly, and the flat surface means you can get right to the bottom and sides of the tin, too.

As with the preparation, it can be tempting to start adding a second coat of paint as soon as you’ve finished painting the first. However, it’s wise to wait until the paint has cured (dried).

“It’s important to allow time for paint to fully dry and harden, so following the recommended drying time is an essential step in the painting process,” explains Bestley. If you apply a second coat too soon then you risk the paint not adhering to the first coat, which can cause bubbling, peeling and streaks. Most paints have a two-to-four hour drying time but do read the back of the paint tin carefully for specific timescales.

“Colour is one thing, but paint is especially formulated for the surface it’s designed for,” says Green. “So using an eggshell finish on woodwork means it’ll adhere (stick) properly, and last a long time. Matt is fine for walls, but often not in steamy bathrooms – where you’ll want a waterproof sheen finish. Take some time to work out what finish you need for the project, because making the right choice will pay dividends.”

Does paint go off? How long does it last? It depends on whether the tin has been opened before or is new but using paint past its best is definitely a painting mistake to avoid. “The shelf life of paint can vary from one year to 10 years,” says Bestley. If you’ve found a previously opened tin of emulsion in your garage or shed then it’ll probably be fine to use if it’s less than a year old, as long as it was resealed properly.

An unopened tin of paint will last a lot longer as the unbroken seal will have helped keep the emulsion away from the elements. However, unopened or not, a lot comes down to storage. “The key is to protect paint from freezing,” explains Bestley. “Once a paint freezes, it affects the consistency and becomes stringy, gritty or lumpy. 

“Old paints had an antifreeze with Volatile Organic Compounds [VOCs] added but they were removed due to the hazardous nature of the chemicals. But this means modern water-based paints freeze quicker and easier.” 

The shelf life then becomes shorter so storing them inside, perhaps under the stairs or in a utility room rather than a cold shed or garage, would mean fewer radical changes in temperature throughout the year, which can help to prolong the life of the paint.

Having to pick loose bristles out of wet paint is a pain. It makes buying the best paint brushes that don’t lose their bristles well worth it. That doesn’t mean having to spend a fortune to find good quality ones; buy the best you can afford.  

Look for brushes that are the right size and have the right type of bristles for the paint job you need to do, too. Synthetic bristled brushes are usually good for water-based paints and natural fibre brushes are good for oil-based paints and varnishes. 

It can be tempting to paint a room by starting with the walls first, because usually there are more of them to paint versus any other surface in the room. However, there is an order to paint a room that you should follow, and for good reason.

“Start with the ceilings and then work your way down, painting the skirting boards last. Paint drips and splatters will completely ruin the final look so painting from the ceilings down will help to keep splatters at bay,” advises Ken Jensen, senior technical consultant at Crown Paints.

There’s nothing more annoying than wobbly, uneven paint lines between ceiling and wall or wall and woodwork, which ruin the look of your paint job. That’s where masking tape becomes a DIY decorator’s top tool. But do you know when to remove masking tape for the best results?

If you’ve painted with a steady hand and not overlapped the masking tape, then the consensus amongst decorators is to remove it once the paint is dry to the touch. This means not leaving it until it’s fully cured, but midway through the drying time (which you can find on the paint tin).

However, if you’ve been a bit slap-dash and the paint has gone onto the masking tape, then peeling off the tape when the paint is still a bit wet is much easier and less likely to pull the paint with it.

I tried this with FrogTape recently. As I pulled the masking tape away from the skirting, on the areas where the paint had dried to the masking tape, it did pull away up some paint which I then had to go back and fill in. Removing the tape on the areas that were still a little wet, perhaps half an hour after painting on a hot day, resulted in nice clean lines.

The angle you pull the masking tape away at is also important – 45 degrees is recommended, as is tackling small sections of tape at a time, especially if you’re not used to doing this job. You have much more control over how you angle the tape, and it reduces the risk of pulling large chunks of paint away too.