How to Open Up a Fireplace: Your Complete Guide
8 mins to read

How to Open Up a Fireplace: Your Complete Guide

# Interior Design

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The 1970s might have been a great decade for music and fashion, but not so much for home interiors. Rooms were swathed in psychedelic brown, wood chip, and wooden panelling as the determined rejection of the past embraced a brave new, distinctly brown future. 

Original features, such as period fireplaces, were boarded over or, even worse, dismantled and chucked in skips.

Then came the 90s, and suddenly everyone was ripping off the plaster in Victorian houses to find old fireplaces and period doors. And, thankfully, we've never looked back since. 

This article is about how to open up a once-boarded-over fireplace to transform the charm and beauty of your living spaces.

Let's get started.   

Should I open up my fireplace?

Open fireplace with fire burning

Opening up a fireplace instantly transforms your room. From an ugly blank wall, you can create a focal point for your space — whether you’re uncovering an old fireplace or building a stud wall faux chimney breast from scratch. 

A fireplace instantly says Home. Even during the warmer months when there's no need to heat your room, an open fireplace or wood-burning stove adds atmosphere and that inimitable hygge, making a space more welcoming and comfortable. 

And in the summer, you can burn a candle in your wood-burning stove to enjoy the hypnotic flicker of a flame without the heat. 

Do you need permission to open up a fireplace?

You generally don't require permission to open your fireplace in your home. However, you may need to consider building regs or planning permission if you need to work on your chimney, especially if it affects your home's exterior look. 

You'll need to consider your chimney. You might have a Class 2 flue, suitable for gas and electric fires but not solid fuel fires. The best scenario is that you discover a Class 1 brick chimney, which is ideal for natural fires. 

However, don't fret if you discover a Class 2 prefabricated flue — it doesn't rule out a real fire. But you may need to consider another fuel type, such as bioethanol fuel, which you can safely burn without the need for a flue or chimney. 

What should I consider before opening up my fireplace?

Living room with open fireplace and decorated christmas tree

Before you apply mallet to plaster, think about what you might want from your opened fireplace. 

Consider what you are going to use your fireplace for.  Do you want a purely decorative fireplace, or do you want it to warm the room? This will have a significant impact on the amount of work required. 

Remember that a real fire requires a Class 1 brick chimney to burn wood or coal. However, if you’re considering burning bioethanol, no worries about the chimney. You can even get a fake flue for that extra-traditional look! 

Finally, a wood or coal-burning fire requires regular cleaning, and your chimney will need annual sweeping. Are you prepared to take on this maintenance? However, biofires are much easier to maintain because the fuel creates no soot, ash, or mess. And you don’t need a chimney, so there’s no annual sweeping. 

How do you know if there’s a fireplace behind a wall?

The most obvious sign that you have a covered fireplace is a chimney breast. But there are other ways to determine if something exciting is nestling behind the wallpaper. 

The knock test

If the fireplace has been boarded over, you'll notice a hollow sound when you knock on the wall with your knuckles. 

If it doesn't sound hollow, it doesn't mean there's no fireplace, but it might indicate that it was bricked in. 

Speak to your neighbours

Find out if anyone else in the street has opened up a fireplace in a similar property to your own. That’s a pretty sure sign that you have a covered fireplace. 

Look for a ventilation brick

If the previous tenants of your home had the fireplace professionally covered, the fitter should have installed a ventilation brick. This prevents dampness. 

Remove the ventilation brick, and shine a torch into the hole to gauge the size of the old fireplace aperture. Hold a candle by the hole — if the flame is drawn into the gap, it's a good sign that the chimney is functional. 

Check for a hearthstone

Lift your carpet to see if you have a thick, heavy slab embedded into the floor around the chimney breast. Again, an excellent sign that you have a fireplace! 

Can I open up my fireplace myself?

Worker opening up a white fireplace


Yes — absolutely. However, be prepared for a lot of mess, so make sure you get dust sheets! 

It's a reasonably straightforward task, as long as you're not changing the shape or size of the fireplace opening. In that case, consult a specialist builder. 

Read on for a step-by-step guide to opening up your fireplace. 

The anatomy of a fireplace

When you’re removing the plaster or brick around your fireplace, look for the following parts:

The lintel is a horizontal (or occasionally curved) beam that sits across the top opening of the fireplace. This is holding the wall up, so do not remove the lintel without additional structural support! You could affect the integrity of the chimney breast and even bring the ceiling down! The lintel could be made of brick, steel, concrete, or even wood. 

The jambs sit underneath the lintel and complete the basic "frame" of the fireplace. Again, the jambs are supporting features of your chimney breast, don't be tempted to remove bricks further than the supporting jambs (unless you're supporting the chimney wall with a temporary brace.

The recess is the alcove opening of the fireplace, extending towards the back of the chimney breast. We don't recommend tampering with the recess as a DIY project.   

What are the UK’s fireplace regulations?

Many towns and cities around the UK are now Smoke Control Areas, which means there's a limit on the amount of smoke you can release from your chimney. 

Additionally, it's essential that you burn seasoned wood certified "Ready to Burn" — this means that there's a low moisture content, producing less smoke. You could get a £300 fine if you burn anything else. 

In Smoke Control Areas, you can burn:

  • Anthracite
  • Semi-anthracite
  • Low-volatile steam coal
  • Gas
  • Bioethanol 
  • Oils or liquids for adapted fireplace

Is an open fireplace safe?

Man in snowboarding gear sitting next to open fireplace

All fires are dangerous if incorrectly used or maintained. However, a well-maintained open fireplace is perfectly safe as long as you adhere to these common-sense safety rules: 

  1. Have your chimney professionally checked for safety — this is your first priority, especially if the chimney hasn't been used for years! A blocked vent will blast smoke and even fire into your rooms! 
  2. Maintain a safe distance from the flames — use a fireguard and don’t stand too close. Open fires often spit sparks, which can cause a house fire. 
  3. Get smoke and carbon monoxide detectors fitted. If your chimney is not operating optimally, your fire can produce carbon monoxide - an odourless, invisible, deadly gas. 
  4. Only burn permitted fuels — never burn old furniture or scrap wood indoors, as it’s likely to have been treated with harmful chemicals, paints, or varnishes. 

Can I open my fireplace merely for decoration?


While traditional fireplaces are attractive decorative features, you may want to help keep your town's air clean. 

Because even Ready to Burn fuel releases some smoke and chemicals into the air, so you might want a greener alternative, such as bioethanol.

Ideas for a decorative fireplace


You might not want a wood or coal burner, but you might still want a real fire that nicely heats your room. 

So, you could enjoy the best of both worlds with a beautiful bioethanol fireplace — bioethanol stoves offering the traditional look of a wood burner or the uber-modern curves of a freestanding fireplace, such as the futuristic Stow White

Bioethanol offers warmth without the smoke, soot, or mess. And you'll never need to sweep the chimney, and you won't pollute the air. 

And bioethanol fuel burns cleanly, so there's no cleaning up, and the fuel is readily available online or from some big hardware stores. 

How to open up a fireplace: the process

Get a skip before you start — you’re going to need it! Lay down protective sheeting, and prepare for the fun!

1. Remove the existing fire

Safely remove your old gas or electric fire. Be extra careful with gas pipes and electrical wiring — get a professional to do it if you’re unsure.

2. Pull away the plaster

Tap the wall for signs of hollowness, then break the plaster away with a hammer and chisel. Start from the air vent and work slowly outwards, being careful only to remove what you need. 

Once you've removed the plaster, you'll get a good idea of what's underneath.

3. Open up the recess

The fireplace opening may have been bricked over, so use a hammer to knock out the bricks gently. Stop when you reach the lintel and jambs — don't go any further, or you could damage the rest of the wall. 

The previous owners may have lined your chimney with a gas liner — remove this, as it won't be suitable for a real fire. 

If you're considering installing a larger fireplace than the original, consult a specialist builder.

4. Examine the cavity

After exposing the cavity, get the chimney professionally checked for damage. 

Use fire cement to repair cracks in the fireback, and check to see if the chimney has been blocked or capped. You'll need to open this up if you intend to burn fossil fuels. 

5. Sweep the chimney

This isn’t a DIY task — get a professional to sweep the chimney. They may need to clear debris.

6. Check the chimney’s performance

Hold a lit candle inside the recess to see if it draws the smoke upwards. If not, it needs sweeping or repairing. 

Want a fireplace, but not to pollute the air?

It's a conundrum, isn't it? You want the beauty of a real flame, but you don't want to pump carbon and pollution into the air, affecting your town's air quality. 

Well, there are alternatives. Find out more about bioethanol by exploring the articles in our comprehensive blog

Positive review of ImaginFires experience

Happy renovating!