Casa100 Build - Chico CA

[UtahBeehiver]

There is really no specific size requirement for weep holes. Since you already have a bit for the rebar, I would just use it. Be careful when you reach the other side, go gently, it will crater out. Option is to drill a small diameter then drill larger from both ends. Silicon some wire mesh on the bottom to keep the bugs out;.

[hillscp]

david s I searched the forum and found reference to the weep holes being 1/2". Is this correct?

[david s]

The standard is 4” thick with steel reinforcing in the lower third of the slab so it’s in tension rather than compression. If making it thinner be aware that it’s strength is proportional to its thickness (halving thickness produces 1/4 of the strength).
the slab should go to the outside of the blocks and fill every second core with concrete and steel bar.
support the cement sheet near the centre with some 4x2, but place wedges under them for easy removal that won’t damage the concrete when you pull them out. Also cast in a few weep holes near the centre of the slab to assist underfloor insulation drying and draining. I use some foam rubber inserted into the concrete after it’s been screened off.

[hillscp]

david s - That is a slick solution. Unfortunately I tend to go to Lowes when looking for ideas and they do not stock those 45 degree blocks so it did not occur to me. I am modifying the sketchup model as I go along to reflect what I "should" have done and I agree that this would have been the best solution for the lintel. Keep me feeding ideas.

The next big thing will be pouring the Hearth.

I intend to use hardi backer as the base for the Hearth and extend it over the block but I'm looking for experienced opinions. I have two questions.

1. Should the Hardi Backer go all the way to the outside edge of the block base or should it only extend to the inside edge in which case the concrete would go over the top of the block.
2. Should I put rebar in the block cores sticking up about 3 inches to anchor the hearth to the base?

Anything else?

Thanks!

[david s]

For anyone following this thread a far easier way to do it is to use these.

https://cdn11.bigcommerce.com/s-5fz3abyf4b/images/stencil/1280x1280/products/964/449/45_single_block__94205.1588611791.PNG?c=1

and these

https://www.bing.com/images/search?view=detailV2&ccid=rJYlDUsW&id=CEE48324210D9158D91D7F50EBF0D9AD55E137E9&thid=OIP.rJYlDUsWq9MRhOITp9OADgHaE9&mediaurl=https%3a%2f%2fth.bing.com%2fth%2fid%2fR.ac96250d4b16abd31184e213a7d3800e%3frik%3d6TfhVa3Z8OtQfw%26riu%3dhttp%253a%252f%252f4.bp.blogspot.com%252f-2TSO3XrSuEc%252fUJbsYtg5ERI%252fAAAAAAAAIxA%252fP16r6pbOelA%252fs1600%252fDSC_0210.JPG%26ehk%3dqao6yVMbr%252brwnKiziSV7kUnbagtiKMJsbQ9MZAvtRLM%253d%26risl%3d%26pid%3dImgRaw%26r%3d0&exph=1071&expw=1600&q=knockout+blocks&simid=607994698688901827&FORM=IRPRST&ck=507F5CCE8D1AA50ECAA596DB6533A90F&selectedIndex=0&idpp=overlayview&ajaxhist=0&ajaxserp=0

[hillscp]

Went to Lowes and bought a hammer drill and a 5/8" bit. Drilled some holes to set rebar. I also bought some epoxy to anchor the rebar. Hopefully I'll pour the lintel this Saturday if I don't decide to brew a batch of beer instead Now I have a hammer drill LOL

[hillscp]

[hillscp]

I would take out the half block at the top of the pic and remove half of the block ion the other side. Then form those two voiids to pour monolithic with the lintel.

Thanks - that is the perfect build! - problem is I already filled the cores and it would take significant effort to remove them now So I built the form now I just need to rent a hammer drill and put rebar in the wall.

[Gulf]

I would take out the half block at the top of the pic and remove half of the block ion the other side. Then form those two voiids to pour monolithic with the lintel.

[hillscp]

I made a model of the lintel form. I'll have to rent a hammer drill and put short pieces of rebar in the sides to tie it to the block base. Vertical and horizontal rebar for the sides and top.

[UtahBeehiver]

+2, both Gulf and I poured mono lintels on our ovens. There is a recent build from Minnesota that did a nice mono pour as well, just search around.

[david s]

The conventional method is to use lintel or bond beam blocks and fill them with reo and concrete tied into the vertical cores of the blocks on the ends.

https://www.google.com.au/amp/s/theconstructor.org/construction/masonry/bond-beam-lintel-block/29496/

[Gulf]

+1 on going with the lintel. You can pour it monolithic with the hearth slab. A bladeless jigsaw will work just as well for vibrating the forms.

[hillscp]

After staring at it for a while I decided to go with the lintel. I think it gives it a more finished look. Maybe I'll tile it.

[hillscp]

Question for everyone. I am thinking about whether I need a lintel across the front opening or if I could get away with just leaving the hearth unsupported there with re-bar going across. I could pour a lintel and tie it to the block with re-bar but I would rather not if I can get away with it. (see drawing)