Wiring in the room behind an open flame fire

So long as the wiring to those sockets is in the other side of the wall, and of course the wall construction is suitable for the fire place (brick or similar), it should be no issue. Any wall you can stick on wallpaper without it going brown (or smouldering !) will be fine for wiring.

Do check though that the cables are not on the side the fire is going and then poked through. If need be they will need to be re-routed.

Mike.

Are there any regulations around this?

Lots - but they're building regs - e.g. Approved Document J

But as Mike says, get the arrangements around the fire right and everything else should be pretty normal.

   - Andy.

Like Mipj1 said, don't set the wires on fire and you'll be fine.

mapj1 said:

Any wall you can stick on wallpaper without it going brown (or smouldering !) will be fine for wiring.

Yes, but it seems to be too early to tell at the moment.

There may be a reason why fireplaces are generally against an outside wall or paired up on opposite sides of an internal wall.

I suppose that it depends to some extent on the material to be burned and the construction of the hearth, but after a few hours, the bricks in our fireplaces glow red hot.

The boxes behind the sockets will reduce the thickness of the wall. I have no idea how thick the wall needs to be, but doubtless your registered installer will know. 

I'm with Chris on this. There must be a reason why there is only one fireplace with none backing onto it in an internal room. Was it external once and has been extended? Has the other fireplace been taken down (chimney pot still there)? What sort of fire is intended to be fitted? 

Need a load more info please.

Note that in Victorian properties the thickness of the back of fireplaces was often only one skin thick and the brickwork was usually poor as it would never be seen. Also products of combustion of solid fuel fires attacked the mortar between the bricks so great care needed when reusing such chimneys.

OlympusMons said:

Note that in Victorian properties the thickness of the back of fireplaces was often only one skin thick and the brickwork was usually poor as it would never be seen. Also products of combustion of solid fuel fires attacked the mortar between the bricks so great care needed when reusing such chimneys.

In the space under the stairs in the terrace house I was raised in was where we hung coats and kept paint and DIY stuff. We could look through the deteriorated joints in the brickwork and see the flames in the fire place of the next door neighbour. I don’t ever remember concern being expressed by my parents which was strange as dad had us all drilled in our fire escape routine. Perhaps we have a different slant on danger in this more enlightened time.

It seems that the principles of building construction have been forgotten. Chimneys are often built "back to back" as it makes the construction easier, but it is not because of temperature! Open fires are not just built against the bricks or whatever, they have a fireclay fireback, and then part J requires an impermeable lining to flue up the inside of the chimney to prevent combustion products from escaping into the rest of the building. You also need an air supply and a CO alarm. The old-fashioned large chimney spaces or inglenooks did not have the fire against the rear wall, thy had it contained by dogs or a basket, as building materials exposed to hot fires for long periods deteriorate badly.

The electrical parts on the opposite side of the wall will be fine.

From AD J looking at  either of the upper diagrams you do not want to be cutting into that 200mm or 100+100+cavity those thickneses mean that the far side of the wall does not get more than slightly warm. In effect on a solid plastered wall means OK to have wires and thin back boxes  into the plaster and render, but not if they are chiseled deep into the bricks/blocks. If need be the fireplace will need a thicker back so the fire is slightly further into the room, - but as has already been said, anyone who knows what they are doing will do this as a matter of course, or it won't get building regs sign off. If it is an under the radar job, then please follow the building regs even if an inspector never sees it.

David Stone said:

It seems that the principles of building construction have been forgotten. Chimneys are often built "back to back" as it makes the construction easier, but it is not because of temperature! Open fires are not just built against the bricks or whatever, they have a fireclay fireback, and then part J requires an impermeable lining to flue up the inside of the chimney to prevent combustion products from escaping into the rest of the building. You also need an air supply and a CO alarm.

Of course. It is much easier to have one chimney breast and one chimney stack (but with all the flues exiting through their own pot) than many individual ones.

Given that a chimney sucks the exhaust gasses away from a fire rather than the fire blowing them up the chimney, I fail to understand the modern business of having flue liners, etc. but it may be a reflection of having hermetically sealed buildings nowadays.

As with all construction matters, selecting the right tradesman can be the most difficult part.

There may be a reason why fireplaces are generally against an outside wall or paired up on opposite sides of an internal wall.

I think it's only a matter of architectural convenience - we've got a fireplace against an internal wall with nothing corresponding on the other side in our 1910 build house (indeed duplicated on the floor above as well) - I suspect down to site layout which means we have windows front & side rather than front & back so the layout of the rear rooms are at 90 degrees compared with the front ones.

   - Andy.