a week of warm and damp will take it up to 80% or so of final strength which will be hard enogh to work on and to hold the mass of blockwork
do any planishing after 24 hrs to give a nice even finish to bits that will show ,a foot of floorboard with a block handle will make an adequate tool to rub the surface smooth
some metal poking up into the blockwork will help tie it all together
keep the blockwork damp as you go along and try to let the mortar for the blocks set off enough before adding more layers ,
when blocklaying a stiff mortar holds the block against gravity better than a more runny bricklaying mix .make sure the blocks are well wetted and take your time with bubble ,string and rubber mallet to get each block set perfectly .if layer one is perfect it is easy to build up
if the oven is to be very heavey it may be worth filling the hollow blocks with concrete as you build up for extra commpressive strength
at a guess the oven will be heavey
I left it longer than you suggested, for a variety of reasons, but I have finished the top slab. Layer of self levelling this week to bed the firebrick oven floor on. First pizza cook scheduled for 2017.
Nick
Joined: 02 Nov 2004 Posts: 34535 Location: Hereford
Posted: Tue Apr 28, 15 3:12 pm Post subject:
2017? Feh! It'll be done before the middle of 2015!
im sure i mentioned it at some point but when you first fire it up ,start slowly with a few sticks for a few hours to dry it gently rather than having steam venting like yellowstone on a busy day( adding several hundred weight of wood and some wp into a damp oven might be rather more exciting than you need )
once it cools down after the first test firing any cracks can be filled with clay or fire cement and then refire with good hardwood .
the best traditional oven wood is hawthorn but other timbers will work ,prunus juniper,and oak all add flavour but avoid things like laburnum and yew for the obvious reasons
would you like a bit of "olaf" he does make exceedingly good pizza dough if you plan ahead and ferment your thin crusts in a genuine napoli style
Nick
Joined: 02 Nov 2004 Posts: 34535 Location: Hereford
Posted: Tue Apr 28, 15 4:16 pm Post subject:
I would love some Olaf, please, but I'm going to suggest you don't mail it this week. I do only have the vermiculite render, and then final coat to add, but, you know, just in case...
I have some starter myself. I wonder if neglect has killed it yet...