Casa100 Build - Chico CA

[hillscp]

[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

[david s]

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

https://cdn11.bigcommerce.com/s-5fz3...611791.PNG?c=1

and these

https://www.bing.com/images/search?v...t=0&ajaxserp=0

[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]

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

[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;.

[david s]

As the inventor of this little innovation, that I’ve been using for 13 years, I should be speaking with some authority, but I’m really not sure. I use a single hole, around 12mm (1/2”) in diam, cast into the precast supporting slab for our product. It works pretty much like the little hole in a saucepan lid, both reducing steam pressure as well as providing a path for water drainage either liquid or vapour. In this regard the larger the number of holes the better I should think. I often remind myself of a new electric kiln that I fired empty (according to manufacturers instructions) up to device temperature. At around 400C (750F) around 100 ml of water began dripping out from one front bottom corner. The water in the refractory, being driven out hitting the cooler metal outer casing, condensing and running down the sides to exit via gravity at the front corner. I was surprised that this occurred at such a high temperature. This also led me to design a venting system to allow steam pressure relief and a pathway for water vapour between the inner and outer domes to the atmosphere.
regarding the mesh over the holes I prefer to place it on the inner or upper side of the slab, but this is only possible if it’s glued on before the floor insulation is laid over it.

[hillscp]

I tied the rebar to the block and poured the lintel today. I'll remove the form tomorrow after work. 24hrs should be enough? I put 4 pieces of rebar in the top. Went pretty smoothly.. My daughter helped.

The only thing of note was that the epoxy I bought to anchor the rebar was a disaster. It cured way too fast and clogged up the applicator. I ended up throwing it away and getting some portland based anchoring cement. Much cheaper and far easier to work with.

[hillscp]

I pulled off the front of the form. Looks really good (to me)! Little steps and victories. Just in case you were wondering - PAM works great as a release. I'll leave the inside of the form up until later this evening. I'm going to have to cut out the center members so I can pull the sides away (the screws face the concrete)

[david s]

I’m not sure what you used as a release agent, I use mineral oil/kerosene 50/50, but it can interfere with the bonding of any subsequent coating applied over the casting if you don’t scrub it off. That’s part of the reason I dilute the oil and apply it sparingly.

[hillscp]

PAM is spray on cooking oil. I did use it sparingly. Almost pure canola oil. Maybe I'll scrub it with detergent, I want to tile it.

[david s]

Yes, scrub it with detergent, let it dry, paint on an acrylic tile sealer, then tile, using a quality outdoor tile adhesive.

[Gulf]

For future builders following: My advice is to not use a release agent of any kind for a surface that will be tiled. The rough surface is what you want anyway.

[hillscp]

I am getting close to pouring the hearth. After that I have a lot of design decisions to make. I'm pretty sold on building a "house" out of metal studs and hardi backer covered in stucco and tile trim.

First things first though; the hearth. I'm using the instructions that came with the kit for reference. They are somewhat ambiguous and downright contradictory in some cases .

Here is my plan for the Hearth construction

• Build a support structure inside the block base using 2x4's. Start by creating a support around the inside edge then suspend horizontal members from the edge support. Leave the vertical supports a little short and shim them underneath so they can be adjusted and removed easily.
  • Question - How far apart should the horizontal cross members be? The widest span is 47" so I'm thinking one horizontal member should do? That leaves ~24" between horizontal support members. I have a recurring nightmare about the whole thing falling down.
• Lay 1/2" hardi backer on the support frame and across the top of the block
  • Question - I have worked with hardi backer before laying tile. Is there any reason to tape the seam in the middle?
• Build a form around the perimeter with 2x6 lumber and 2x4 vertical supports. The concrete should be 3.5" plus .5 inches of hardi backer making a 4" thick hearth.
  • Question - How should the form members be fastened at the corners? Just screws through the lumber and into the end grain? I have a fear of it coming apart. Screwing into end grain scares me.
  • Question - can I be successful mixing 18 60lb sacks of concrete in a wheelbarrow with a hoe or should I rent a mixer? Reasoning is that I'm not sure how fast I need to be getting all the concrete in the form
  • Question - How far apart should the rebar be. Instructions say 1/2" rebar 12" on center. Should I add mesh?

Thanks in advance. the next thing will be framing the house with metal studs. I've never worked with them before.