4 courses up... and a big question

[Throw Deep]

I'm having a "sinking spell" and need some advice asap.

As the title says, I've got 4 courses up on a 36" oven and it is looking great. This is my first attempt to lay brick and am coming on up the learning curve...but I'm feeling pretty stupid at the moment. Somewhere along in the third course I started noticing gaps between the bricks (the invented "V" so...I started buttering the side of each brick with Heat Stop in addition to the bottom before setting it.

Now showered and tired after a full day of laying brick I've been thinking about those cracks. So I go out and set a light in the center of the oven and, dang it, I can see the light shining through those cracks between some of the bricks.

My question...is this a problem...meaning I have to tear it all out and start over or will the insulation coating render my problem...not a problem at all?

[Ken524]

Re: 4 courses up... and a big question

Throw Deep,

Can you post some pictures for us to look at?

[Dutchoven]

Re: 4 courses up... and a big question

Definitely post some pictures...there very likely is a workable solution other than tear down...Dutch

[Throw Deep]

Re: 4 courses up... and a big question

I'm not sure if this link gets you to pictures but I think it will. Thank you for your help.

Bob


Picasa Web Albums - Robert - Pizza oven

[Acoma]

Re: 4 courses up... and a big question

Cracks between bricks, not within the bricks is nothing. Yes, mortar those areas, clean them after a few minutes, but do only a couple bricks at a time or you will be further frustrated. As for the inverted V, you will need to photo a spot so that proper advice can be given. With the inverted V, Ken has posted ways to handle it, I believe after his 7th course? Let's say you have the V, eyeball the gap and bevel the top to bottom of each brick connecting them. Example is .25 gap at bottom needs to have .125 shaved from each top corner wall. Again, check out Ken's gallery for further clarification too. Lastly, photo these issues for us to better help you.

[Acoma]

Re: 4 courses up... and a big question

Sorry, just saw your Picassa. You don't need to sweat things. Do go back and mortar the inside areas to create a flush wall, and clean as you go.

As for the outside wall, I prefer to have my mortar flush with bricks as I go as well, and you can do that too. You have 1-2 days of clean up to do with this.

Give the mortar a day to cure, then find your dome floor center. Once found, be sure your dome is circular for each course. You may not be at the arch, but worry about that later. For now, you can use a marker, or whatever, with a string for consistancy, and mark irregular spots. Once done, use your grinder and carefully shave the walls to create the nice round dome wall. Trust me, better now, then further issue later. I have done it on my 6th and 7th course and am glad I did.

[Throw Deep]

Re: 4 courses up... and a big question

Thank you Acoma, Dutch and Ken...it's a relief that I don't have to knock down and re-build the walls. I pointed the gaps inside and out and worked on the "high spots" with my new grinder...which Acoma gave me an excuse to get...I've wanted one for a while. I've been using the string method from a center pivot so I'm fairly round and level. I'm planning on marking and grinding inside edges as I go up on each course.

The cuts on the bricks are okay so far but cutting out that "inverted V" may be beyond my capacity.

The current plan is to use 2 or 3 FB insulating blankets and add a few more inches of vermiculite/portland mix over the resulting dome. Hopefully that will seal up any small air gaps if there are any left.

One other question for down the road...when curing through a progression of fires...should it be cured before the insulation is put on or after...or does it matter?

Bob

[asudavew]

Re: 4 courses up... and a big question

One other question for down the road...when curing through a progression of fires...should it be cured before the insulation is put on or after...or does it matter?

Bob

Probably the most debated question on Fornobravo.
Either way is just fine.
But if you want to patch any cracks that could form during curing, just use a blanket so that it can be removed for repairs.

Dave

[Ken524]

Re: 4 courses up... and a big question

Looks like you have it under control, Bob.

Just remember to butter the sides of the bricks from here on out so any "V's" that you have are filled with mortar. When I did mine, I would butter the top of the previous course then the side of the new brick. Tap the new brick into place until mortar oozes out those cracks then clean it up with damp sponge after it sets for an hour and you'll be good to go.

(Beautiful pool back there!)

[gjbingham]

Re: 4 courses up... and a big question

I buttered the bottoms and both sides of each brick when I laid them, but I did not custom cut the majority of my bricks. I look at mortar as just being a solid space filler that mimimizes the possibility that a brick can move in any direction. I may be totally wrong, but I believe the actual bond strength of mortar to brick is very very low. Therefore, at least in my small mind, full mortar joints reduces possible brick movement problems related to thermocycling. (That said, you could easily make an arguement for leaving spaces to allow for brick expansion/contraction and I might believe you )

Make sure that if at all possible, you don't allow mortar joints to line up anywhere between rows. Almost all my cracks occurred at areas where the mortar joints were within an inch or so of the next row.

As far as the existing gaps in the mortar, I'd make a wetter mix and finger it into those voids, or spend 5 bucks on a grout bag and attempt to force it into the bigger ones.

The lower courses are almost vertical, so it may be that their strength due to the sheer weight of the bricks in a downward didrection will not be affected by voids, especially if you use cladding on the outside. There's a couple of discussions in this forum about failures of arches. If memory serves, it's somewhere in the middle third. That is where I'd get serious about structural integrety. - my advice, to be taken with a grain or two of salt.

[Dutchoven]

Re: 4 courses up... and a big question

OK...I concur with what everyone else has said...as far as an easier way to fill your gaps(insert funny line here) ...I would suggest getting yourself a grout bag...you should be able to find it at your local favorite help yourself home center...I recommend HD over the other one because the quality of the bag is better...I have just used this method to repoint worn brickwork on a 100 year old building...you would loop the mortar down with some extra water to be easier to squeeze out of the bag(just like icing a cake)...you would be able to stick the tip into some of those gaps and fill them up...wait until the mortar is "thumbprint" firm and then scrape it off flush with the surface...same can be done on the outside...for future courses you can keep a bit of looser mortar handy for the grout bag to touch up any area you might need some in...there also have been builders who used shims to set the angle of each brick and then the grout bag to fill the voids, removed the shim and then filled it's void also...
As far as the cut...if you are using a wet saw that will work...you could use your grinder to knock a bit off OR...you could rub the two bricks together for a good while and that will do it...this option will get 2 done at the same time......just kidding...that is so 18th century...called gauged brickwork...could you imagine rubbing bricks together to get the right joint...amazing!
I think you workmanship is quite commendable...keep your eye on the ball the rest of the way
Best
Dutch

[Throw Deep]

Re: 4 courses up... and a big question

Thanks to everyone for their tips and suggestions today. I'm hitting the sack and will be back out on course 5 early tomorrow. We have forecast another 60 degree sunny Alabama day and I'll take another day off work to move this along. My son is returning from Iraq on his R&R on March 1 and I'm determined to serve him a pizza when he gets home. With a 2 week cure schedule, I need to knock this thing out by about Wednesday. Wish me luck. Bob

[gjbingham]

Re: 4 courses up... and a big question

Go Bob go! Agressive schedule. If the weather holds, I don't think you need two weeks to cure it. 10 day should do it, being gentle. Take your time and do a good job. If nothing else, enlist a few of your friends to cut bricks or help in othe ways.

Your son will be home for more than just a few days, I hope. Maybe not if he's got a girlfriend closer to to his base, huh? Give him my thanks for his service in harm's way.

[Acoma]

Re: 4 courses up... and a big question

Well, our advice does vary somewhat. As you can see, our styles and creative ways still create a functional oven.

As for brick cutting, do you have a wet saw? If so, your inverted V should not be hard to correct as I had explained earlier.

For mortaring, wow! Unless your previous course is still moist from soaking, the bricks will suck up the water from the mortar FAST. I will throw my 2 cents. I use a small painter cup and fill it 1/2 way to last 2 to 3 bricks. I then mortar the brick to use (bottom side). I then do a QUICK mortar to the brick just placed down. I then use my fingers on the face side bottoms to confirm allignment. I also eye the spacing between the two side bricks, and use a temporary shim with marking to confirm lift in the back. While holding down the brick with my hand for a minute max, I use use my free hand to grab a sponge and wipe excess mortar from the inside face, and areas that have dripped down the wall. After a minute the mortar bonded enough to let go, the excess mortar on the face has been cleaned off, and I have also finished pressing any needed mortar into empty spaces on the top side. After 2 total minutes, I remove the shim and pour from the cup the mortar into the gap in back, pressing it in and holding the delicate brick that is bonding as well. I then use my moist sponge and delicately press the mortar into place in the back so that my brick is filled to the outside wall. I also wipe the empty area next to the brick just placed down so that mortar does not harden in the process which may create an improper lift, or issue for the brick that will go down.

Now I know my steps are time consuming, but if I had 1-2 people helping, I would fly through my build. As for you, take from our notes and use the steps to help you get it done. Do not rush through this just to have pizza for your son and jeapordize the integrity of the oven that I am sure you want for longer than a 1 night party.

[Throw Deep]

Re: 4 courses up... and a big question

Good morning, all. Help is on the way today so I'm hoping to increase my 2 course per day rate substantially.

My reason for doing it myself is to do it right...so I won't rush it even trying to make a schedule. My soldier boy will be here for a couple of weeks so March 1 is not an absolute drop dead date, but I would like to be ready about then.

Thanks for taking the time to give detailed advice. I read a lot before starting but once into the project it is so much more valuable.

Bob