Fire surround size vs size of fireboard

[mattcyp]

Apologies for another fire thread, but I haven't managed to find any info on my current question so far. 

BS8511 says that the hearth should extend 150mm to the sides of the stove so, for a squirrel which is 388mm wide that would be a 688mm wide hearth.  The BS then goes on to say that the vertical fireboard behind the stove should be as wide as the hearth. 

This makes sense, but I can't find a supplier of either Skamol Super Isol (e.g. Midland chandlers) or Skamol Skamotec 225 (which has lower conductivity values than the super isol) that comes in boards bigger than 1000mm by 610mm.  

So, to me the choice appears to be either have a slightly narrower hearth and vertical back than the regs suggest, or to have to buy two sheets and try and put a join (and potential weak spot) somewhere on the vertical back.

Has anybody else come across this conundrum, and if so, a solution. 

Thanks!

[rjasmith]

Have you tried John Opie's (link here)?

Richard

[mattcyp]

Yeah, they have been very helpful in putting me onto Skamotec 225, but couldn't send a piece bigger than 610 by 1000mm out to me. 

They did suggest some glue for joins, but I wasn't quite sure how well it would mantain the heatproofness. 

Thanks for the input
Matt

[nbfiresprite]

The solution is to use a lap joint with the edge faces to be joined angled at 45 degrees,  This was recommand to me by the Danes themselves.

[mattcyp]

Thanks firesprite - that makes sense.  With that in mind, I'm plannin to use a 610mm sheet in the middle with two strips or around 100mm on the edges (so there are two joins, but both are a long way from the hottest bit of the surrons as they're quiter near the edges.   Would you make the lap/ mitre joins with the plane of the lap perpendicular to the direction heat is travelling, or perpendicular to it?

Parallel:

                            ____\\__________//______
                                         ________
                                        | Fire         |
                                        |               |

 

 

Perpendicular (if that makes sense):

 

                            ____//__________\\______

                                         ________
                                        | Fire         |
                                        |               |