Fire bricks or Pavers?

[pjm5755]

I'm new to the Forum, but have been thinking about building a wood fired oven for some time, and the information on the Forum is really helpful.

Whilst I understand that the risk of ovens failing can be avoided by using fire-bricks, I have a supply of pavers (the type used on driveways) which are very hard and I think I've read that they may have been used before in parts of bread ovens. It also will keep down costs.

Does anyone have any experience of using pavers in wood fired ovens, or possibly even seeing how they end up after being placed in an operating wood oven at high temperature?

I don't want to build my oven with pavers, only to find its been done before and failed. Or is this an experiment worth trying?

Any ideas, please?

[tapir]

Hi pjm5755, welcome on board. You could always build a series of fires on one of your pavers and see what happens.

I seem to recall on the original WFO forum, a chap called JerryM spent a lot of time and effort experimenting, you might want to check out his posts there:

Simple build - build started

Dog hutch - experimental WFO

good luck and let us know!

[pjm5755]

Thanks for the links.

I can't see the pictures, but assume thats because i'm only registered on the'new' forum, and would need to also register on the 'old' forum - is that right, anyone?

looks like Pavers have been tried, but i'm still not sure of their thermal properties and resistance to spalling under high heat, unless anyone has any experience of them in their WFO.

[tonyb]

My gut feeling is that using pavers is risky. The ones I've used for paving have been made of a mix of materials, so when you cut one in half it looks all mottled if that makes sense. The risk is that the individual 'bits' expand at different rates and cause spalling or worse.

[turkey]

Hi pjm, the old forum is locked for posting but if you register you will see the pics, there are loads of old build diaries so have a good look round there also.

I am sure loads of folks have used lavers, I seem to remember Terry our admin mentioned someone using them, hopefully he will pop up.

[slowfood]

When I built my brick oven I built the entire dome out of regular clay housebricks and used fire brick on the floor, The oven is sound. Get Russel Jeavons book "My Brick oven" He explains all about the bricks and also the easiest way to build a brick oven. Hope it helps

[cannyfradock]

Pjm

There are 2 types of pavers. Clay pavers and concrete pavers. Clay pavers....and clay quarry tiles have been used for the coking hearth. There has been some debate lately on the forum as to....them being able to stop from cracking or spalling over a long period of time.....time will tell. The clay pavers are 25mm thick and are usually red or blueish in colour.

Concrete pavers are about 50mm thick and come in various colours. WE advise against using any concrete product on an oven build although Richard Scadding uses concrete pavers on the hearth of his mobile clay oven.

If you can always use fire-bricks for your hearth and dome. A second best for building the dome would be storage heater bricks or reclaimed red clay bricks...or then class b engineering bricks. Dont use concrete bricks/pavers for your dome.

I believe RS's clay oven with concrete paver floor is small (60cm?) so it's not so difficult to continually feed a "ticking over" fire to keep the hearth hot enough for pizza baking. In any case it will take a lot more wood to keep the heat in. Any bigger with the diameter of the oven and these pavers will act as a heat sink.

Terry

[h12rpo]

Class B engineering bricks are relatively cheap here @ 40 p each

www.diy.com/nav/build/building-materials/materials/bricks___blocks/-specificproducttype-standard_bricks/Class-B-Clay-Engineering-Brick-L-215-x-W-102-5-x-D-65mm-9273679

[dougclay]

I got the solid blue engineering bricks at GA-Day, regraded because of discolouration and only about 20p each. The blue ones absorb and retain heat better than the red.
They take the heat too, no signs of fracturing or crumbling......

[ashleyreye]

I have read about many type of pavers in one of the websites and has given complete information about fire bricks and pavers. Actually, I want to use fire bricks to my home, Because these bricks are prevents from hazards. Fire bricks are available in affordable prices with good quality of material.

Link removed by Admin

ukwoodfiredovenforum.proboards.com/index.cgi?board=info&action=display&thread=1

[triggaa]

Hello all,

Any update on how the engineering bricks have faired?
I'm just about to construct a pizza oven and have the chance to get a load of engineering bricks for free.
I'd be much obliged to have any feed back on people who have used them.
On another forum someone spoke of exploding blue engineering bricks!

All the best

[cannyfradock]

Hello Triggaa...welcome to the forum.

On my first Pompeii I used a mix of old clay reds and engineering bricks. I built the oven blind without knowledge of how these ovens work, so I missed adding vital insulation layers below the hearth and above the dome. Although I don't use that oven...I have fired it up quite often (it won't hold heat but will reach extreem temps) and so far none of the bricks have spalled. On our old forum we did have 1 or maybe 2 people who said that they're bricks did spall......with bits suddenly flying off at speed. Maybe these bricks were of a concrete substance?.......it seems.....unless you get some first-hand feedback that you know as much as the majority of us that....some people have said that they can spall.

Saying that...many builds have been built on a shoestring which have been very successful using old red clays and engineering bricks (as long as they're not concrete....same goes for pavers. Clay will take and hold heat but concrete won't.

When I fired my clay brick oven up for the 2nd time, the oven was damp and I had no right in putting any more than gentle heat in the oven....I didn't. I fired it up to the hilt to see if any bricks would spall......they didn't, but the dome cracked in several places due to immense heat in a damp oven. Here's some pics of the firing...



Terry

p.s....I stood about 3 feet away and tried to peer in to look at the bricks and singed my eyebrows and lost my eyelashes.

[h12rpo]

If they actually are engineering bricks ( commonly called blues); then you wont have any trouble with spalling or exploding. My informant reckons they are fired at temps in excess of 1200 degrees ! As to their heat retention properties, I think they'll fare better than red clay house bricks but not as well as firebricks.
He also reckons that they were routinely used up till about 15 years ago in the local steelworks to line the furnaces.

I had some of these "ex steelworks" blues above a replacement window in my last house and ruined countless masonry bits trying to drill some holes for a curtain rail !

[dougclay]

In to my 3rd year with a hearth of Engineering blue (pavers) and the are fine. I removed them last year to fit under hearth insulation and some thermocouples and the were all still in top condition, so back they went..
They take a long time for the heat to transfer uniformly top to bottom, but then retain the heat for many hour afterwards.

The face side is nice and smooth, perfect for a hearth with nothing to caught on with the food or the peel..

[cannyfradock]

...great feedback guys. After h12rpo's post I googled the manufacturer (Ketley) to try to find some data on the "blue's" or "solid Staffordshire blue's"...but couldn't find anything on their refractory qualities.....but did find out they are class A engineering bricks fired to 1200 degrees....quite right Ian.

I had my doubts wether they would retain heat so it's always a bonus when someone ....thanks Doug, comes back with 1st hand knowledge of using the product in question. It's nice to hear, Doug that these bricks work.

Terry