Eric's WFO build

[eprante]

Hello everyone,

I have decided to stop lurking and start my build thread. I have cut down a tree, dug a footing for a retaining wall and poured the footing thus far. Today as I was dry stacking the bricks for the retaining wall I discovered that the blocks were not 8x8x16 as I assumed, but 7 5/8" by 151/2". Since everything I know about masonry I have read here, and I was planning on incorporating my retaining wall into the form for the slab( 16" blocks work out perfectly if you stack them end to end for 80") So my question is: do I find blocks that are exactly 16" or do I mortar in between them?
Question 2: I have decided to use the homebrew hi temp mortar, any problem using fine beach sand? I hope not since I lugged home about 70 lbs of it today.


Eric

[KINGRIUS]

Re: Eric's WFO build

Yeah all the concrete blocks around here are 7.5" by 15.5". Make up the difference with mortar(1 part type N masonry cement, 3 parts sand).

I was asking all kinds of questions about sand last month. Answer: All sand is high temp resistant. You don't want to use a sand grain that is too big to work with. Beach sand sounds okay to me.
Don't forget to post your progress pictures. We like pictures!
Um by the way, I think beach sand might be federal property but you didn't hear it from me.

May your build prosper,

Darius

[eprante]

Re: Eric's WFO build

I am sure I broke several laws taking it from the beach, but I made a clean get away. The ocean is always replenishing the supply. Thanks for replying. My daughter borrowed the camera this weekend, so I will get pics up next week, hopefully with more progress.
E

[ttriche]

Re: Eric's WFO build

Lars' tip is key: Sift your sand. Your 1:3:1:1 mortar will be *much* easier to work with.

I got crushed by work but now I'm coming down the home stretch on my own oven. Will be nice when it's done, lots of winter braising and roasting in store.

[dmun]

Re: Eric's WFO build

Is ocean sand salt bearing? Is that a problem?

[jmhepworth]

Re: Eric's WFO build

I dry stacked the concrete blocks without putting mortar between them. That makes them all a half inch shorter, so you have to include that missing half inch in your calculations. But having built a four foot high enclosure for some gila monsters using mortar between and on top of the blocks, I can attest that it's much, much easier to dry stack them and fill them with concrete. We had much more trouble keeping the wall on the gila monster enclosure level, square and plumb than we did dry stacking them for the pizza oven stand. I'm not a good enough mason to do it mortaring them together.

Joe

[eprante]

Re: Eric's WFO build

dmun,
Beach sand from close to the tide line may have some salt in it, but salt being water soluble gets washed out of the sand up on the beach. There is 100 yds of beach to the high tide line, enough for the salt to be dissolved even by the very infrequent rain here in San Diego. At least I would think so.
Eric

[RTflorida]

Re: Eric's WFO build

From what I have been able to find online in a quick search. Beach or sea sand can contain varying amounts of salt, depending on where harvested and whether it was wet, dry, or damp. It is recommened that it be thoroughly sifted and washed (other organic contaminants are more detrimental than the salt).

As for the salt itself, it has and can be added to cement and mortar mixes to lower the freezing point in colder climates. The rule of thumb is no more than 10% salt content in the mix (I don't know if this is by weight or volume), in any case, I don't think beach sand contains nearly that much salt. Supposedly, if you stay under the 10% there are no detrimental effects and no reduction in strength.

The beach sand itself seems to be the biggest problem. It is generally not recommended for construction use. It is considered a "tumbled" sand with rounded edges and smooth/slippery surface to the grains; accordingly, portland cement and other bonding agents do not adhere well with beach sand, lessoning the strength.

As inexpensive as sand is, I would just buy it. It has already been cleaned, sifted and is the right stuff for the job.

RT

[eprante]

Re: Eric's WFO build

I have been under the radar for some time while I dug out the tree roots, built footings, a retaining wall and formed up the foundation. I am ready to pour concrete this weekend. It is exciting to actually start working on the stand and oven. Thus far it has just been a lot of hard work, and my family keeps asking when is there going to be some bricks?
Eric

[Tscarborough]

Re: Eric's WFO build

It is not recommended to use beach sand. It does contain salt and will attack the rebar (not too big a worry in this case) and will cause efflorescence (may or may not matter depending upon your finish.

[eprante]

Re: Eric's WFO build

The beach sand was for the hi temp mortar home brew, but I think that I have decided against it.
E

[eprante]

Re: Eric's WFO build

was able to pour the foundation last weekend with thanks to my son, nephew and father in law for the help. Hopefully I can upload the picture.
Eric

[ThisOldGarageNJ]

Re: Eric's WFO build

Hey Eric,
Welcome to the club,,, so many people dont realize how much work goes into a proiect like this,, even as your seeing the "simple" digging for the foundation is a pain.. I hit a few roots too...

But, It looks like your off to a great start...

Cheers and keep going
Mark

[eprante]

Re: Eric's WFO build

Thanks Mark, a load of block for the stand and prep area are being delivered today. It will be nice to be working above ground so my family can actually appreciate that there is progress being made.
Eric

[Neil2]

Re: Eric's WFO build

Do you have a construction joint across the "wings" of your slab" ?

If not it will crack there. To control the cracking, you can cut surface construction joints using a angle grinder, a thin cut off blade and a straight edge. Cut about 3/8 inch deep.