Fireplace Recess Prep for Multi Fuel Stove - Hearth Paint, Mortar for Pointing, and Black "Stuff"

[Oxbow16]

Hi all

 

Apologies for hogging this forum of late.  The stove will be installed soon hopefully, and then I'll stop with all the questions!!  

 

The stove is going into a fireplace recess which I'm now finishing the prep on.  There's a few things I'm not sure about and wondered if anyone can help please?

 

1. The constructional "hearth" in the recess could do with a lick of paint.  Any suggestions as to what paint would be best to use?  The fitter said emulsion should be ok, but a little googling seems to suggest emulsion isn't so great with high temps.  I should add we are having a Woodwarm Fireview with no legs.  So the ashpan section of the stove is in direct contact, although I won't really need to paint directly beneath the stove; just the visible parts to the side and front...

 

2. There's the odd gap in the pointing, some of them very deep (150mm).  I'd like to fill them before the stove goes in but I'm not sure what' best to use and whether it needs to be heat resistant?  Saying that, I've no idea what the existing mortar repairs and pointing were done with?! 

 

3. One of the side walls is covered in "black stuff".  I'm happy with the aesthetic; in fact I like it.  But could it potentially cause any problems?  If so, I'm thinking best to remove it now while I can...  

 

Photos below. 

 

Thanks a million

 

 

 

 

Edited February 3, 2021 by Oxbow16

[Oxbow16]

Hi again

 

RE my Point 2 above.  I've read through the Q&As on this page:

 

https://www.screwfix.com/p/cementone-general-purpose-mortar-grey-5kg/36857

 

and the chap says this is not suitable around fireplaces.

 

So just wondering what would be best... I've read lime based mortars are good for around fires, but they take a long time to cure and the install is quite soon.

 

Would a basic mortar be ok do you think and if so...:

- What's the best ratio?
- What type of sand?
- Do I need to use a plasticiser or any additives?

 

I can't work out if the ready made mortars in tubs are literally just cement and sand mixed, or if there's more to it?!

 

Also, would it be best to ram bits of stone or similar into the gaps so that they're not as deep?

Many thanks

 

Edited February 5, 2021 by Oxbow16

[Oxbow16]

Here's some photos of the holes in question:

 

 

 

 

 

 

 

 

 

 

[Gav_P]

I’d happily chuck any mortar in those holes. Think about what’s already there... has that been “approved” for use... worst case is it dries out and falls out again.
 

I wouldn’t paint it, leave it as is.. it has character.

If you really want to paint it, I’d use some garage floor paint. Hardy stuff. 

[Vijay]

I've used this in the past https://shop.vitcas.com/vitcas-heatproof-mortar-10kg.html and they'll probably do everything you need https://shop.vitcas.com/products/heat-resistant-materials.html

 

Or you could try this stuff too https://www.toolstation.com/fire-cement/p38992?store=BK&utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=CjwKCAiA9vOABhBfEiwATCi7GPGty09XagmrIofU8n7Gb4XofRaM92-FlJ-29R3vL9ubhYcVIk1eehoCAVcQAvD_BwE

 

You could then try spraying the bricks with a high temp rattle can of spray paint

Edited February 5, 2021 by Vijay

[Oxbow16]

Thanks Vijay, but we don't want to paint the bricks as we like them as they are.  

 

As for the heatproof mortar, I did find that and thought to begin with it was what we need.  But on closer reading I think this is for inside open fire places, for fire bricks, and that kind of thing.  IE - where temps reach the 1000C+ mark.  On top of that, the vitcas mortar says "It is also not suitable for use as a rendering or gap filling material."

 

I'm thinking standard normal mortar will be fine, but just not sure whether to use sharp or soft sand, plasterciser or no plasterciser, ready mix, etc.  

 

Cheers