If you’re currently thinking of replacing your fireplace with a cultured stone one, you might like to consider the following tips on cultured stone fireplace construction. Cultured stone isn’t a euphemism for a particularly refined or expensive stone. Cultured stone could also be referred to as faux or mock stone, not being a naturally occurring substance.
To the observer cultured stone will look perfectly natural but it is in fact a composite, usually made from a natural rock that has been ground to a powder and mixed with cement and possibly sand, to make an artificial stone.
The advantage of cultured stone is that you can create any texture and color of stone you desire – so that it exactly fits in with the décor of the room in which you will construct your cultured stone fireplace.
Preparing for the Construction of your Fireplace
Having fully removed the old fireplace surrounds and mantel, make sure the wall surface onto which the cultured stone fireplace will fit is clear of any loose material and is reasonably smooth. Especially if the cultured stone fireplace construction is going on to an outside wall, fit a moisture barrier such as a heavy grade tar paper to act as a moisture barrier. This can be quickly fitted using a masonry staple gun.
As you’ll be fitting stone onto the wall you need to make sure the substrate to fit it onto is a good and sound one. Spread a scratch coat over the area that the cultured stone will be fitted to with a trowel and hawk.
Depending on the surface area this is required over you might need to first add some lath work, to ensure the scratch coat adheres well. Before the scratch coat dries gouge some scratches in to it, this roughened surface will help the cultured stone mortar to bond to the scratch coat.
Fit the Mantel First
Before starting to fit the cultured stones you need to fit the mantle, and then build the cultured stones up to it. Having decided the height you want the mantel to be, mark the center for its position and then with a level mark the length along which it is to be fitted. Another advantage of fitting the mantel now is that you can cover up the screws holding up the mantel with your cultured stones.
Fixing the Cultured Stone
Before starting work fixing the stones, if you have any specially prepared cornerstones – put them to one side so that they are easily recognizable as you’re working. Then, starting at a bottom corner apply a generous, half inch, layer of the mortar mix to a cultured stone and press it firmly onto the scratch coat, holding it in place for a few seconds.
When applying the mortar to the stone create a bevel shape away from the edge of the stone, as you press the stone and mortar against the wall it will naturally ooze outwards anyway. Don’t forget to offset subsequent rows of cultured stone with ones cut in half, to avoid creating continuous lines of mortar vertically as well as horizontal ones; also periodically check your working for levelness and that the cultured stones aren’t bulging unnaturally.
You’ll need to cut some of the cultured stones to get a good fit around the mantel if nowhere else. You can use a masonry hammer to do this, but you’ll get a much better ‘line’ using a diamond tipped wheel on a grinder, a four inch grinder should be sufficient here. With all the stones in place you can then fill in the joints, or point them, with the mortar mixture.