[Knight Family]

So in our new house, we've decided to refit a cast iron fireplace. Has anyone done this or point me in the right direction on what to do? DIY is not an issue as I'll put my hand to any tasks from brick laying  / plastering but small / med jobs.

I've done a search of web sites etc but helpfull advice always good.

[alfieplot162]

hi,i got a cast iron fire place fitted and they used bonding its like plaster but stronger, i hope this helps alfie

[Stree]

Right........ assuming its an original casting and not a repro.
First... At the back of the piece an at either end towards the top there should/will be either a small protusion like a hook or an eye or something similar These are  there so that you can get a heavy gauge wire attached to the casting......... When I say heavy gauge I mean something the thickness of coathanger wire or thicker. Anything less is not worth doing .
You will need about 4 inches of a loop of this wire sticking out after uts fastened to the casting.
Next. Offer the casting up to the wall in its final position. Mark a spot in line with where the wire is attached and just above the top of the casting on the wall. If its a cast top that bolts on do this with the top unbolted and removed. If its an unfinished top meant to be finished with a wooden or other surround just use the top of the casting as a guide.
Remove the casting and  get a scutch chisel or an SDS bit and make a hole about inch and  a half diameter and about  five inches deep.............So that the bottom of the hole is level with the top of the casting.. The next bit is where the skill comes in. You have to plug the hole with lead.. Strips of lead, full depth of the hole but lining the sides, so that there is room for the wire to go in the middle of the  hole to its full depth. with the lead in place, offer up the casting again and feed the wire into the lead lined cavities........
Make sure the casting is level and plumb. Feed more strips of lead in to the holes until you cannot feed any more in, the get a drift or piece of steel rod and begin to hammer the lead into the hole. As the lead is hammered in more room will appear and more lead must be fed in until ot is absolutely packed in, the wire will be locked into the lead and the lead will have taken up shape with the irregularities in the hole in the masonry so if its hammered in good and tight it has locked the casting against the wall.
The mantle top. either a cast one or a timber/plaster/ stone one will cover the hole although you can skim it over with plaster anyway if you wish..... The bottom of the casting is held to the wall either by brackets if its a cast not meant to have a surround to finish it or if it is meant to be finished with a surround then when the surround is fixed to the wall this will retain  the casting.
If you prefer to use bonding as suggested then go ahead..But first ask yourself how  it is going to fix a cast iron piece to a wall?  I know it is done this way but is inherently unsafe unless there is a substantial mechanical fixing also..
You will be aware of how much these things weigh. Imagine that tipping forward on to the hearth rug..........
PS yes I have fitted these, and the above is the traditional way. If its a repro then it may even have drilled lugs so you can fix it with rawl plugs !
Good luck anyway, and work safely

[Knight Family]

thanks, Its not got holes or anything I can see. I think its a repo with use of a wooden surround.

going to have a good look at it easter weekend and see when I can do.....

[mumofstig]

Mine was re-attached with long screws into the brickwork through flat metal straps/strips diagonally across the top corners. These were hidden by the wood surround.

I suppose that the bigger size mirror brackets would do the same job and also be hidden
Good luck, they look lovely when finished

[Stree]

If its a repro that is meant to be retained by a timber or other surround then the surround will hold it to the wall. In this case bonding will be used to seal the inner edges of the surround to prevent air being drawn through any gaps. This is the only function of any bonding, it is not an adhesive apart from on a porous strata such as a masonary or plastered wall.
Mirror brackets are ideal for retaining a surround to a wall, 2 at each side top and bottom and  ideally they must be sunk into the surround (mark around where the bracket is to be fastened and pare with a sharp chisel until the bracket sits flush when screwed to the surround)  and  the protuding wings bent slightly backwards, with a corresponding hole chipped in the plasterwork, to allow it to be skimmed over level with patching plaster when fixed, so an invisible fixing.
It is important to use brass or stainless steel screws for this, ordinary screws will rust and fail.
If the surround is being fixed to a decorated wall then you can cut the wallpaper with a very sharp blade and carefully peel back a section where the bracket will be fixed, then afterwards skim it and refix the paper.

[Knight Family]

great thanks, so thats one simple task. The other one will be the fire back as its integrall, so I'm aware I got to back fill through the vent flap, and then fire cement the top to allow slope to stop sut collecting.

But is there anything to note or be aware off??

[Stree]

Please clarify exactly what you refer to as "vent flap" As good an overall description as you can would help.

[Knight Family]

Is it called the dampener? Basicly its a solid cast iron fireplace with incorporated fireback, and at the top of this there is a flap that can be opened (when in use) and closed shut when not.

[Stree]

What size is the aperture of the vent/damper?
If it is big enough then do the following:
 first clean out the hearth fireback with a stiff brush and then liberally wet the brick or render there. wire brush the back of the cast iron where the infill is going to contact and rub down with a bar of soap......Reason for this is so that it acts as a mould for the following:
Prop the surround in its final position and brace with timber props at the top so it does not move and put something heavy like bags of sand at the feet so they too do not move...
Break up bricks, concrete, rubble, or use large pebbles etc  ready to use as infill.
Next is where bonding comes in handy again. Mix a bucket of bonding, making it sloppy enough to pour/push through the vent but not too sloppy so that it runs out of the bottom as water. Some water will seep through, the right mix will keep it to a minimum.
Once you have a bucket full in then drop in a bucket full of the rubble........Continue like this until the mix is about 2 inches from the top, leave for a couple of hours to set ( test it through the vent ) then remove the surround ( the soap should prevent the bonding coming away with the surround ) and complete by capping the infill on a slope as desired to the required height. Leave to set overnight and it should then be ready for the surround casting fixing.

[mumofstig]

They lined behind the metal with a layer of cardboard before infilling, then removed it before the final fixing. They said this was to allow room for the fireplace to expand when it got hot.........do they still do this I wonder

[Stree]

Usually down to manufacturers installation instructions.
One thought though, if the cardboard takes care of expansion rearwards, what takes care of it sideways and up and down?
I reckon the cardboard serves the same purpose as the soap, IE stop it bonding to the casting .
Saying that, it would do no harm to use the card, just that the gap will fill with soot instead.