Metal blanking plate to protect from wood burner stove?

[HappyHippyDad]

My customer is having a wood burner installed.

The stove installers have said he needs to get the 2 sockets that are directly behind the new stove position removed. They are approx 9-12" away (guess).

It would be a right pain and expensive for the customer to have the cable removed from the walls and hidden in the ceiling. I was thinking a metal blanking plate would be sufficient? Is there such a thing that would be suitable?

I have found this, but it says 'grey in colour' making me think it has some kind of finish on it which may just burn off, not sure.

RS PRO Grey 2 Gang Blanking Plate | RS

uk.rs-online.com

 

[littlespark]

Metal is a heat conductor, so it’ll get hot behind the plate just as much as in front.

It’ll possibly not get so incredibly hot, as the back of a stove will be insulated as to not damage the wall.

 

[LeeH]

Going from my wood burner experience, it and the surrounding area gets hotter than the sun so no, a plate will be no good.

Can you disconnect/reroute the circuit leaving the cable in the wall? If it’s decommissioned it shouldn’t be an issue for HETAS.

Cut the cable off flush, and fill it full of cement.

 

[HappyHippyDad]

Thanks for those 2 replies, it's given me a bit to think about.

I have some ceramic fibre wool left over from when I needed some. From LittleSparks post i can see that the metal plate is going going to get extremely hot, so the wago's and conductors left inside the back box cannot be in contact with the back of the metal blanking plate. I could wrap them in the ceramic fibre wool which has a very high fireproof temperature resistance, something like 1000°c?

 

[Dave OCD]

I don't think that would do very much to prevent the heat getting to the pvc insulation and eventual heat damage may well be inevitable. Much better to disconnect the cables and reconnect together as required remotely from the Wood Burner, I know that's probably easier said that done but they decided to have the thing and it's not worth risking insulation failure.

 

[davesparks]

If you wrap the conductors and joints in thermal insulation then it may protect them at the terminations, but it will also mean they are now installed in thermal insulation with the obvious implications for the size and CCC of the cable.

But you still need to consider the cable in the wall behind the wood burner which will also be getting rather hot and will have it's effective CCC reduced as a result.

 

[Lucien Nunes]

The way to protect something from radiant heat is to put something reflective on the front to minimise the amound of heat absorbed, then an insulator to prevent whatever is absorbed penetrating, then as little as possible behind so that heat that does get through the insulator can dissipate. But as mentioned whatever you do to keep heat out will also keep it in, so there is a real risk of this cable running too hot unless it is genuinely within range for Iz with one side insulated at whatever the resulting ambient will be with the stove burning.

When we got our narrowboat there was just a metal reflector panel behind the wood-burning stove which did get painfully hot. When we upgraded the stove some 10 years later, we removed the metal and found signs of scorching to the woodwork behind. We put Supalux heat-resistant insulation board in its place and tiled it, and poked a thermometer in the wall cavity to check it was at a sensible temperature.

 

[Dave OCD]

When you compare the relative ease and low cost of getting the cables well out of the way of the woodburner with the potential future problems coupled with serious access issues after it's installed I'd say it's the only sensible option really.

 

[123]

Most likely find that there will be a plasterer involved anyway so if needing to cut a hole in the ceiling they should be able to patch that when they are on the job for little extra cost.

 

[HappyHippyDad]

Thanks for all the replies everyone. It doesn't sound like there is any suitable way of keeping the cables in the position they are. I think a hole in the ceiling will be the only option. I'm seeing the customer tomorrow and will give them the good news!

 

[davesparks]

I think a hole in the ceiling will be the only option.

Is the flue going up through the ceiling?
If so there will already be some disturbance of the ceiling anyway that you may he able to coordinate with.

 

[happysteve]

The way to protect something from radiant heat is to put something reflective on the front to minimise the amound of heat absorbed, then an insulator to prevent whatever is absorbed penetrating, then as little as possible behind so that heat that does get through the insulator can dissipate.

When we got our narrowboat there was just a metal reflector panel behind the wood-burning stove which did get painfully hot. When we upgraded the stove some 10 years later, we removed the metal and found signs of scorching to the woodwork behind. We put Supalux heat-resistant insulation board in its place and tiled it, and poked a thermometer in the wall cavity to check it was at a sensible temperature.

Ooh, snap!

Also used to live on a narrowboat.

When we moved on land, we got a Zeeschouw to play with, took out the fridge, and fitted a tiny wood burner ("Sardine stove"). I offset the Supalux sheets (double layer on the bottom just for strength) from the wood work by one inch offcuts of copper pipe, then used stainless steel sheets as a reflector and something to easily keep clean. Worked really well!

 

[littlespark]

Coal fire in a touring caravan…. Beat that!


Back to the OP;
I had one job where’s new wood burner was going in corner of room.. double socket in the way.
Was a partition wall, so just removed cables back to next socket… which was through the wall in the hallway.

I never thought that the heat might go right through the wall. I assumed the wall would be clad in insulation to prevent heat from getting through completely.
Wall was filled with glass wool anyway.

 

[HappyHippyDad]

Is the flue going up through the ceiling?
If so there will already be some disturbance of the ceiling anyway that you may he able to coordinate with.

Yes, it is. I'll have a closer look when next there. I completely forgot about it today when with the customer as we were talking about other bits he wants doing.