Friday, 21 February 2014

Building a wood fired bread and pizza oven - A box to hold insulation

It will probably never be said that my choice of exterior cladding for this wood fired oven is anything to look at, but on the other hand in terms of function it is just a box to hold all the insulation in.  In this case that is going to be a very large amount of insulation.  It is thinnest at the front around the door at a thickness of about 11cm.  Around the remainder of the oven there is a gap between oven mass and insulation of approximately 20 cm.  Under the hearth there is 10 cm of Foamglass.

Exterior of the oven
 The outside of the oven has been tack welded together, in each corner there is steel angle which allows some overlap and allows some adjustment of the panels.  The corners were clamped together and checked with a spirit level.  The box is held up by first attaching some lengths of steel to the concrete slab with rawl plugs and  hex head screws.  The panels are then also welded to those lengths of steel.

Foil faced ceramic and mineral wool insulation can be seen
 The front of the oven and the exterior cladding is separated with layers of foil faced insulation, ceramic on the hottest side and then mineral wool.  This needs to be kept separate from my baking so this will be encapsulated with sheet aluminium 0.2 mm thick.  This is  enough to hold its shape, but not so thick that it will conduct lots of thermal energy away from the hot side of the wall envelope.
Aluminium sheet to encapsulate insulation around the door
Tomorrow I am hoping to finish insulating the oven and fire the oven ready to bake on Sunday and Monday.