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Tom B 08-16-2009 08:11 AM

My mason screwed up. Should I start over?
I just realized that my mason, who supposedly has 18 years of experience, laid all the bricks for the first 4 courses of my oven DRY. From what I read, this was a critical error and the mortar may have dried instead of cured. Doesn't help too that it was over 80 degrees yesterday. And this was after he made a point of saying how the plans said the bricks needed to be soaked. I feel this is a critical error, and he should knock down the first courses and start over, but even if that is on his nickel, this has a to me in time and schedule conflicts. So here is my question community: has the integrity of my dome been compromised and should I insist that he start over?

Les 08-16-2009 09:23 AM

Re: My mason screwed up. Should I start over?
I didn't soak my bricks. Granted, there was some moisture from the wet saw, but as I got to the top they were completely dry (the glue didn't work if they were wet). If the brick joints look good, you most likely do not have a problem.


mluttropp 08-16-2009 09:47 AM

Re: My mason screwed up. Should I start over?

I just finished the soldier course on my oven and I only soaked the bricks for a miniute or so just to make sure the mortar stayed workable as I put things together. This morning I thumped the soldier course with my knuckle and I found it made an interesting bong sound like a bell. I suspect that is an indication that all of the bricks have been bonded together. You may want to tap yours and see if it makes a similar sound. If you are really worried you could try and pull on of the bricks off. It it does not come of easily I would suspect you are just fine.

captkingdom 08-16-2009 04:56 PM

Re: My mason screwed up. Should I start over?
I don't think you mentioned what sort of mortar you are having him use. If it is a Portland cement concoction it is not too late to mist it and keep it wet for a period of time for curing.

Mitchamus 08-16-2009 06:20 PM

Re: My mason screwed up. Should I start over?
Soaking the bricks just makes them easier to lay (& cut), it stops the mortar from drying out too quick while you get them positioned in the right spot.

If you're good at what you're doing, (i.e. - fast like a proper mason) you shouldn't need to wet the bricks, at least at first while they can be laid relatively quickly...

just my 2 cents...

ThisOldGarageNJ 08-16-2009 08:25 PM

Re: My mason screwed up. Should I start over?
are you using heat stop 50 mortar ? I only soaked my bricks for a few minutes, just to keep the dust down and help keep the blade cool when cutting. Many of the dome bricks I cut with a chisel tool and didnt soak at all. Though I did mist the dome during construction. It sounds like you should be ok,, Dont ask him to take it apart, ask him if he guarentee's his work ??

Tom B 08-16-2009 08:51 PM

Re: My mason screwed up. Should I start over?
I did use Heat Stop 50. The bricks were cut with a wet saw in advance of laying them but they were very dry. I went to the web site for Heat Stop 50 and found an article under a "how to" link: Building a Masonry Firebox with Refractory Mortar. Here is the link: Build Masonry Fireboxes

The article says "Hydraulic-setting mortar sets up, or cures, like Portland based mortars rather than drys. Premixed or air-drying mortar does dry...Because the pre-mixed refractory mortar is not a hydraulically setting mortar (it dries out rather than cures by chemical reaction like ordinary mortar does) the mason can make very thin joints and doesn't have to pre-soak the firebrick. "

This strongly implies that the bricks should not be dry when set, because the Heat Stop 50 (dry mix) cures, rather than dries. I am going to call Heat Stop in the AM to confirm this. As for my relationship with the mason, he is an out of work mason who I just hired for this job, so there is no guarantee here.

If I am correct, the bricks should have been wet, so I will back where I thought I was...wondering if the whole damn thing will collapse or develop nasty cracks.

One thing I was thinking about doing, if I decide to not force him to tear it down and begin again, is to cover the exterior of the dome with a layer of refractory mortar, after the dome is in place, to bind it all together. I would not be doing that normally, because this will be an enclosed oven, but I might now because of this issue.

Les 08-16-2009 09:11 PM

Re: My mason screwed up. Should I start over?
Tom - it will not collapse. I only used the mortar on the back side to maintain the gap distance and my oven is working perfectly. You WILL get cracks - we all do.


dinoforno 08-17-2009 07:13 AM

Re: My mason screwed up. Should I start over?

My dad was a mason and of course he thinks we are all nuts. They did not have HeatStop 50 in his day. And the ovens he built in the old country are still standing...there was no science as I put it to the work that is on the this forum. Although he is impressed at times when he hears what people have done and the use of heat stop 50 is not all that new as he remembers at the end of his career using special type cement/morta for brick fireplaces. He has never had a problem with the curing process. When I shoe him the work that is being done on this forum by masons and most importantly non masons he is very impressed but for a 77 year old work horse he would say that it is fine the way you have it. Especially if you are going to cover with mortar layer or blanket.

Then again he is old school I am not going to say he is an expert at this by any means but he has been saving me. A lot of time even if science meets old school is like oil and water.

The one thing he said was the old churches and arch's of Rome in some cases are still standing today. It is not the mortar that is keeping them together it is the structure of how the brick is placed and the weight is disperesed properly.

Good luck!

Roadkyng 08-17-2009 07:33 AM

Re: My mason screwed up. Should I start over?
I wonder if the masons in ancient Pompeii used 'refractory mortar' and soaked their bricks before building? :D

Seriously - you are having the same kind of concerns we all do when building. That it won't be perfect and it will fall or crack. As others have pointed out these things are fairly simple. I have to keep reminding myself that I am not working on the Space Shuttle. I am covering the outside of my bricks with a mortar layer after I make sure all gaps are filled with brick chips. I want all the thermal mass I can get as I intend to do baking as well as pizza.

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