Heatproof Plaster on to fireline board

Hi

I have justed had a hole in the wall fire installed into a false / bulit out chimey breast and it has been boarded with fireline board. I am now looking to plaster the board and was wondering if anyone had done this before and what they have used.

I have seen Vitcas and a few others do heat proof plaster but they all seem to say that they need to go onto screed and cant be apllied to plaster board.

Any advice or suggests welcome

Don’t like to distress you but Fireline is not suitable as a lining board for a chimney breast; can I also ask what you used to support the lining board, not timber I hope? Fireline does provide additional fire protection (class 0) over standard board (class 1) but is only designed to withstand a one-off exposure in the event of fire. It’s still a Gypsum based board &, as such, is not suitable for continual exposure to temperatures above 49 degrees C, it will most likely fail fairly quickly. With elevated temperatures you need a high temperature board such as Supalux which is suitable for boiler lining applications.

I’ve used Vitcas plaster around stoves but never over lining boards, it’s always been over a conventional sand/cement/lime render which, done correctly, will withstand the heat as good as Vitcas heat proof screed. Vitcas finish plaster should still work OK over lining board, given the correct preparation.

Here ‘s a link to a similar archive thread;
//www.diynot.com/forums/viewtopic.php?t=224751
A search will throw up many others, one or two with a whole bunch of links on relevant topics I’ve put together.

I assume you’re also aware that installing a stove is subject to Building Regulations.

Thanks for the info

If i use the supalux will timber supports be ok if they are kept to the correct distance stated inside the fire manual?

Also will the Vitcas plaster go straight onto supalux, i have read on the vitcas site that it can go straight onto mineral board, is this the same sort of thing?

The fire is in the process of being installed at the mo (can attach a picture if need be to help explan) but when it comes to pluming in the fire that will be done subject to Building Regulations i.e not by me.

I have had a quick search but not really found the answers to my questions so really appreciate the help and advice.

Richard C said:

Here ‘s a link to a similar archive thread;
//www.diynot.com/forums/viewtopic.php?t=224751
A search will throw up many others, one or two with a whole bunch of links on relevant topics I’ve put together.

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Sounds to me that the plastering wiki is screaming out for an update from you on the merits of heat proof plastering.
You are our resident expert.

dazpoynter said:

If i use the supalux will timber supports be ok if they are kept to the correct distance stated inside the fire manual?

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How are you constructing the false chimney breast? What are you doing about a flue liner? You cannot use any combustible material within the distances stated in the B Regs. personally I would not use any form of stud construction even if it were steel framed. The flue, fire opening & hearth construction are also subject to Regs compliance not just the physical fire installation. Here’s another link for you explaining the relevant Building Regs;
http://www.stovesonline.co.uk/flue-distance-to-combustibles.html
and anther very similar thread to do with constructing a false chimney
//www.diynot.com/forums/viewtopic.php?t=250360
You will see that in this case the OP went for block construction in the end.

dazpoynter said:

Also will the Vitcas plaster go straight onto supalux, i have read on the vitcas site that it can go straight onto mineral board, is this the same sort of thing?

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As I said, I’ve used Vitcas plaster before but only over render base. I have, however, successfully plastered other similar construction boards with Gypsum plaster, even when the manufacturer says you can’t! Similar to practically all construction board, Supalux is a high suction background as far as plastering goes & such backgrounds can be difficult to plaster but it can be done with the correct preparation & if the spread knows what he’s doing. Boards must first be sealed first to control the suction, this involves PVA coating at least 24 hours before & left to dry. A bonding coat of PVA is then applied in the normal way & plastered while still tacky. Vitcas does behave slightly different to conventional gypsum finishing plaster but this should not present any problems to an experienced plasterer.

dazpoynter said:

The fire is in the process of being installed at the mo (can attach a picture if need be to help explan)

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Pictures are always helpful.

dazpoynter said:

but when it comes to pluming in the fire that will be done subject to Building Regulations i.e not by me.

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Plumbing in; interesting, what type of fire are you planning to install? You need to be careful & ensure you employ only a Registered Installer for the type of fire your having who understands all the relevant Building Regulations (there are several) & will give you a compliance certificate at the end of it. Using an unregistered installer or DIY will entail a Building Notice submission, inspection & possible witness testing before your LABC will issue a compliance certificate.

The fire is a balanced flue Gazco Studio 2.

Here is a pic of how to install the fire from the instructions which i have followed:



And here is a picture of what i have done:



The fire is only resting in place and will be installed (plumbed in as i called it) to all the correct regulations by a professional.

I have also just spoken to the company i brought the fire from and they said that they use Fermacell although after reading it it doesnt seem to be as good as Supalux. If i was to use Supalux would the 12mm stuff be fine.

Again thanks for your help.

So it’s a gas fire you’re installing, things are now starting to make a little more sense . I don’t have specific experience with gas fires, only solid fuel wood burners & multi fuel stoves so have been looking at the manufacturer’s installation instructions for your particular stove. These state combustible material must be a minimum of 50mm from the sides of the stove but this seems very close; Building Regulations Part J http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADJ_2010.pdf state a minimum of 75mm for an unshielded installation, reducing to 50mm when fitted with a 25mm thick non combustible shield (see diagram 39); the stove instructions seem to be at odds with this & don’t even specify a minimum thickness of shield (board) to use, not that I can find anyway. It’s difficult to see from your photo how much you’ve allowed because of the polythene sheeting, is there an air gap between the stud & side of the stove? Because of the above ambiguity, I would advise you seek further guidance before you go proceed! The sides of the fire opening must also be shielded a minimum of 400mm above the fire. Did you consider using their cool wall kit?

12mm Supalux will be OK to line the front with but given what I’ve said above, you may need to go thicker on the fire opening to comply with B/Regs. You will also need some additional support noggins in that studding. Not familiar with Fermacell but it doesn’t seem to say what it’s made of or suitability as a boiler lining material; if it’s a Gypsum based board I can’t see it being any better than plasterboard as far as withstanding constantly elevated temps around a fire.

I assume you’ve checked that the position of the B/flue outlet will meet the minimum required dimensions to any openings? Needless to say you must have it installed, tested & commissioned by a Registered Gas Installer.

Thanks Richard for your time and effort, really appreciate it.

With regards to the B/Flue all falls with the correct regulations and so does the gas fittings.

I have been in touch with the fire company that sold me the fire and they say they use Fermacell on their installs so i then phoned Gazco and they recommend to used Masterboard or if i really want to i could use Supalux. They also said that it should be 12mm thick as stated in the instructions on the top of page 22 and i quote 'Line the aperture for the appliance with 12mm thick non- combustible material as shown'. I then asked the reason about the 50mm clearance and why it was not what you said and they gave the reason that as its glass fronted and is therefore a self-contained unit all the regulations are meet inside the fire structure, basically it has a shell / case over unit giving it the necessary space.

I have now come to the conclusion that i will leave 50mm around the fire as stated (400mm above) then have a lining of 12mm Supalux around the internal of the stud walling and the have a 12mm Supalux board over the front of the stud wall which will then be covered in Vitcas heatproof plaster.

Thanks again Richard C and any other advice or info would be great.

dazpoynter said:

I have been in touch with the fire company that sold me the fire and they say they use Fermacell on their installs so i then phoned Gazco and they recommend to used Masterboard or if i really want to i could use Supalux.

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Masterboard I’m also familiar with &, being a calcium silicate board, it’s broadly the same as Supalux. Fermacel may be the same spec but I could not find any info on their website that says what it’s made of!

dazpoynter said:

I then asked the reason about the 50mm clearance and why it was not what you said and they gave the reason that as its glass fronted and is therefore a self-contained unit all the regulations are meet inside the fire structure, basically it has a shell / case over unit giving it the necessary space.

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Hmm, not sure; sounds like a bit of waffle to me but they are, after all, the manufacturer & their advice should be (but not always) gospel! For the price of a phone call I would still talk to your LABC.

dazpoynter said:

I have now come to the conclusion that i will leave 50mm around the fire as stated (400mm above) then have a lining of 12mm Supalux around the internal of the stud walling and the have a 12mm Supalux board over the front of the stud wall which will then be covered in Vitcas heatproof plaster.

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Sounds OK but I would check with LABC regarding the above; personally I think 12mm will be OK but it’s all going to be down to your RGI to sign it off! If you have one in mind, I would check that they are happy with what you’re doing. As I said before, I don’t work with gas installs & I’m not sure if RGI’s can sign off the other Building works your doing; you should always clear it with them first & work within their guidance.

dazpoynter said:

Thanks again Richard C and any other advice or info would be great.

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Just come back whenever you need to, no problem; sensible people are easy to help!

dazpoynter said:

The fire is a balanced flue Gazco Studio 2.
And here is a picture of what i have done:

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Very nice. I nearly went for a Gazco Studio - not cheap are they! Went for a Drugasar instead still waiting for it - been on order and paid for since December 2nd last year and still no definite delivery date !!!!

Just ordered my metal Gyplyner and Supalux today - feel violated . Have you got any updated piccys of the install?

How are you doing Rich?

hotrod said:

How are you doing Rich?

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I'm fine mate but could seriously do with some sun

Hi. I came across your post while searching for some fire info.
I've just purchased the same fire as you have. Nice pic by the way.
I just wondered how you got on with the project mines being fitted next week didn't know weather to use stud or have a bruck chimney breast built.
I was also thinking of mounting a tv above. What's you thoughts. Do you have any pics of completed project

Many thanks. Chris.