Plasterboard Chimney Breast – Yes Or No?
If you’re trying to pretty up an old home, one of your first stops will likely be the old, grungy chimney breast. While it’s not exactly easy work (though more time consuming than challenging), there are a few ways to make it look a bit better. The most common approach you may find online will be to plaster over the old fireplace. Applying a plasterboard chimney breast is not only entirely possible but a relatively easy and good new look. While I personally prefer the look of bare brick, not everyone does, and that’s okay!
A plasterboard chimney breast is both safe and entirely possible to apply.
Keep reading for a breakdown of what you’ll need, and how to do it.
Plasterboard Chimney Breast – Options
Now, we’ve actually covered this a bit in the past in our plasterboard fireplace article. The conclusion we came to there was that a plasterboard fireplace isn’t the best idea for a seemingly obvious reason – plaster isn’t fireproof. A chimney breast, on the other hand, is a different story.
Some people don’t like the look of bare masonry and would like to cover it up. Like we said in the linked article above, this comes with a few choices. You could paint the masonry with a mist and skim coat, apply a concrete render, or plaster over it with the right process – don’t worry, we’ll get to that in a moment.
The long and the short of it is that if you’re dead set on applying plasterboard over the masonry, you can. But there are other options that are both cheaper and, in my opinion, look better. With that out of the way, let’s get to how you should apply a plasterboard layer over the bare masonry of a chimney breast.
Plasterboard Chimney Breast – Application
There are two main ways to apply plasterboard to bare masonry – the dot and dab approach, or building out support for the plasterboard. Let’s start with the dot and dab, and move onto the (admittedly) harder second option after that.
To apply plasterboard with the dot and dab approach, you apply thick lumps of specialised adhesive onto the masonry. After that, you just… press the board into place. This is generally not a wonderful option if you plan to actually use the fireplace. This is for one reason – unless you get a heat-resistant adhesive, you run the risk of it running (and failing) when the masonry beneath is heated.
The other option is a bit harder to accomplish in an aesthetically pleasing way, but it is entirely possible. This path involves building out a specialised stud support system for the plasterboard. Since we’re assuming that you want to use the fireplace, it’s important that you do this right. Some forums may suggest using a timber support system – they would be wrong.
Because there’s a fire that will be burning, heating up the masonry, it’s absolutely vital that you choose the proper material. Using a specialised, heat-resistant stud system will ensure that heat transfer doesn’t damage your plasterboard outer layer.
Alternatives & Other Important Knowledge
Another option you may see suggested is using a sand cement finish (render), covered by plaster. Gypsum (plasterboard) is generally not great with heat, leading many people who want a plaster look on their chimney breast to opt for this route. While it’s entirely possible to install plaster and plasterboard over a chimney breast, it may not hold up long term.
Another common suggestion for sealing the corners of your chimney breast is to use corner beading for the corner of the plastered chimney breast. While I cannot personally vouch for this argument, I’ve seen it reiterated several times that this is actually the wrong way to go about it.
The issue lies in the fact that a corner bead will be subject to contraction and expansion when exposed to heat. The alternative approach suggested was to freehand your corners. While this is likely the better solution, it’s really rather difficult to do as an amateur.
When to Call a Professional
This is the part where most people check out. Hiring a professional defeats the purpose of DIY plastering, but there are cases where it’s the prudent thing to do. In this particular case, I highly recommend hiring a professional plasterer. Plaster and plasterboard are not known for their heat resistance, and using the wrong method could have disastrous results.
While it’s a great ego boost to brag that, “yeah, I installed it myself,” it’s less nice when your hard work starts to crack. For this reason, along with the number of variable approaches, I have to side with the professionals here. There are a lot of choices to make, such as how you’re applying the plasterboard, and what it’s affixed to. Even one wrong decision could spell disaster for your project. And without being able to actually assess your chimney breast, it’s hard to give accurate answers.
Paying someone who does this for a living can be expensive, yes. But do you know what’s more expensive? Replastering a heat-damaged chimney breast. And if you have to do that, you’re likely going to be kicking yourself for not heeding my advice.
While applying plasterboard over a chimney breast is entirely possible, it requires a bit of knowhow and specific knowledge of the home. While I can recommend building out a stud support system for your home in comparison to dot and dab – I may be wrong. Without being able to assess how your home is laid out, I can only offer basic guidance.
Hiring a professional to lay plasterboard around your chimney breast will result in a few things – you pay someone to do the job (which costs money), you get a beautiful, modern chimney breast, and you don’t have a damaged chimney breast in a few months or years. All of those, minus the cost of the professional, are good outcomes – so take my advice. At the very least, consult with a professional plasterer to get solid advice on what not to do before continuing.