DIY Pizza Oven Build

[lgw]

We've recently completed a modular pizza oven build at a community garden we run in Lewisham. We build a sturdy base out of 10 oak sleepers with a connected side table. We used fire cement to fix the dome to the fire brick base then covered the dome in vitcas outdoor oven render, followed by 1 inch of fibre wool insulation, followed by chicken wire meshing and a further layer of the vitcas render. We ran out of render just before we could finish the second layer.

Because we were under time constraints to get the project ready in time for an upcoming event we finished the rendering with Bostik ready mixed fire cement. The cement is gradually going off after 3 days however seems to be curing extremely slowly. We've lit a few very small fires to begin the curing and it is gradually hardening however has shown a few minor cracks here and there(which we've filled with the same fire cement product).

Does this sound like it will harden properly as the fire cement tub does say not to use for rendering?

[downunderdave]

Oct 22, 2018 21:32:18 GMT lgw said:

We've recently completed a modular pizza oven build at a community garden we run in Lewisham. We build a sturdy base out of 10 oak sleepers with a connected side table. We used fire cement to fix the dome to the fire brick base then covered the dome in vitcas outdoor oven render, followed by 1 inch of fibre wool insulation, followed by chicken wire meshing and a further layer of the vitcas render. We ran out of render just before we could finish the second layer.

Because we were under time constraints to get the project ready in time for an upcoming event we finished the rendering with Bostik ready mixed fire cement. The cement is gradually going off after 3 days however seems to be curing extremely slowly. We've lit a few very small fires to begin the curing and it is gradually hardening however has shown a few minor cracks here and there(which we've filled with the same fire cement product).

Does this sound like it will harden properly as the fire cement tub does say not to use for rendering?

If you built from a modular kit then it should have come with instructions which you should follow. As the outer shell is really only a weathercovering and does not see high temperatures it does not need to be  made from a refractory material, a normal cement render is sufficient. 1” of insulation is generally considered inadequate, with 3” normal. Did you insulate between the firebrick floor and the supporting sleepers? If not they’ll probably burn and you’ll have trouble keeping an adequate floor temp up.