Due to regs, hearth takes up 36% of room space?

[Alycidon]

Pretty sure I have seen this elsewhere and have replied in detail a few weeks ago,   the drawing looks familiar.   You will recall I was concerned about the height of the beam above.

 

The regs appertaining to the installation of wood burning stoves are  Approved Doc J, 2014,  the front section only,  the rear is for oil appliances.   You can download a free copy from the web,  no need to pay, its a big doc so dont print it !!. 

 

Hearth requirements are:

 

A,  To the rear,  if the wall to the rear of the stove is non combustible and at least 200mm thick then a 50mm clearance is needed at the rear.  I assume this is going into a brick built chimney.   If its a false breast with a combustible ( plasterboard) wall to the rear then fit the Charnwood optional heatshield, (see specs below),  you can then come down to 100mm or slightly more.

 

B,  To the sides,    A, within the opening,   there is NO legal minimum.  We would strongly advise 150mm each side but will install down to about 100mm each side.   You need a good airflow around the stove to allow the air to circulate and get the air coming out into the room.   B,  if the stove projects into the room beyond the front of the fireplace opening then you must have a min hearth of 150mm each side.

 

C,  In front of the appliance.    The requirement is actually only 225mm from the foremost part of the appliance.    However we recommend at least 300mm.  Door on the Aire ( I am a Charnwood dealer) is 470mm wide,  most of which is glass.   So while 225mm is the minimum then a hearth covering a wider depth would be recommended,   you dont want a bit of hot ash dropping on the carpet or wooden floor from the glass.    You could go 225mm,  then lay a piece of glass of the floor in the winter,  that is one solution.  If the floor is tiled then its not really to much of an issue. 

 

https://www.charnwood.com/files/documents/specifications/aire5.pdf

 

I would advise the installation of the optional Charnwood direct air kit if possible,  this ensures that incoming external air is always at the same pressure as the air at the top of the chimney thus the stove works well.  We do have an Aire live in our Buckinghamshire showroom,  without the air kit installed, and it still works very well though.    I think you said this is a new build,  in that case air ventilation to the stove room is a legal requirement irrespective of stove size on all houses built since 2008.  a direct air supply into the rear of the stove resolves this problem.  

 

PM if necessary,  if a builder is installing this then I am a bit worried,  ideally get your local Charnwood dealer to supply and install.  

 

A

 

Edited May 23, 2020 by Alycidon

[aesmith]

On 23/05/2020 at 18:33, slim reaper said:

The area also has to be higher rest of the floor area so bang goes the whole of the floor as a hearth...which I presume was a joke .

That surprises me, do you know why that is?  I can't see the requirement mentioned anywhere on a quick look.  When we had the Rayburn the "hearth" was actually lower than the floor.  It was a concrete floor with two layers of Marley tiles glued down, so the "hearth" was made by cutting off the tiles for an area in front of the Rayburn, and painting the bare concrete with some heatproof paint.  Mind you there was not Building Warrant or anything when we did this, although the stove installer was pretty knowledgeable and methodical so I think he'd have let us know if that wasn't acceptable.

[slim reaper]

From my understanding the hearth needs to be on a different level making it more difficult to extend the carpet or rugs into the danger zone

If you look at diagram 27 of part j of building regs it shows it

Edited May 25, 2020 by slim reaper
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