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Editors:

Put your name here

Graphic Design:

Jean-Baptiste Vervaeck

Version:

Date:

CEB Microhouse Build Guide

v1.0

Jan 1, 2020

Open Source Ecology Build Guide Series

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Table of contents

Prelude: Notes on Using this Guide

  1. Introduction
  2. Design Requirements
  3. CAD
  4. Bill of Materials
  5. Tools
  6. Build
  7. Finish Checklist

Appendix

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

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Notes On Using this Guide

TED Talk Lin

ABOUT: This guide - the CEB Microhouse Build Guide - is part of a build series for the 50 Global Village Construction Set machines. The intended audience is people who are building the world around them. If you want to start a business building microhouses, please consider the Summer of Extreme Design-Build for immersion training.

HOW TO USE: You can use a QR code reader to scan the bar codes to access content online.

COLLABORATION: This is a collaborative effort. You are invited to help edit this guide. You can edit this document or make a copy, make your edits, and email us describing your proposed changes. To join our open source product development effort, join our Developer Team, or get hands-on experience in our Workshops. For other ways to get involved in OSE work, see the Getting Involved page on the OSE wiki. You can email us at info@opensourceecology.org

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  1. Work Breakdown Structure

Coordination

Template with formatting

Bob and Mac - tool list

Marcin- Bond Beam

Joe - Slurry and Cement - Mixing

Aidan - Foundation�

Pieter - Mesh and Stucco

David - initial truss support - design + reality

Patrick - Scaffold

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  • Foundation

Aidan

The MicroHouse Belize foundation consists of two components:

  1. Cyclopean Footer
  2. Concrete Stem Wall

These two sections of the foundation were poured in two days by two workers working for 7 hours per day.

The foundation used 5 bags of cement for the stem wall and 13.5 old, rock-hard bags of cement for the footer. About four 40 foot pieces of rebar were used in total. Roughly 15 wheelbarrows of sand and 19 wheelbarrows of gravel were used.

½” Screen was embedded in the stem wall for Basket Technique

https://www.youtube.com/watch?v=k5GV5USvT3U https://www.youtube.com/watch?v=W--bci1C_JE https://www.youtube.com/watch?v=7mzvEgDLPn4 https://www.youtube.com/watch?v=N_akSziGAH4https://www.youtube.com/watch?v=EcNodWLK BEw https://www.youtube.com/watch?v=XItoxQYSorw

https://www.youtube.com/watch?v=9ROrmRYOwf4https://www.youtube.com/watch?v=AKQCN0_ILRk Howdy folks Dustin Reddusk here, i’m contributing through out with some youtube videos and other references on the how to’s that are established ways to approach the DIY maker. The above videos are different ways of building and pouring footer fundations.

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  • Foundation

Step 1: Marking Location

Put 2 stakes in each corner of the house. See next page for exact stake locations.

Cut 1 stake 8” above the ground. Using a string level, mark the other 15 stakes and cut them to the same level as the first stake.

Using a nail driven in to each stake as a mounting point, run string along the outside edges of the foundation.

You now have marked your foundation and can begin to dig

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  • Foundation

First Step

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  • Foundation

Step 2: Digging Footer

Using pick axe, shovel, and digging bar, dig the footer.

The footer should be around 18” deep according to local builders.

For the Belize Microhouse, the footer was dug 18” wide and 18” deep.

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  • Foundation

Step 3: Pouring Footer

Using large rocks and concrete, fill in the trench. Use the strings to level the footer

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  • Foundation

Step 3: Pouring Footer

You can also use the forms for the stem wall / bond beam to level the footer.

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  • Foundation

Step 3: Pouring Footer

You can also use the forms for the stem wall / bond beam to level the footer.

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  • Foundation

Step 3: Pouring Footer

You can also use the forms for the stem wall / bond beam to level the footer.

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  • Foundation

Step 3: Pouring Footer

You can also use the forms for the stem wall / bond beam to level the footer.

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  • Foundation

Step 3: Pouring Footer

You can also use the forms for the stem wall / bond beam to level the footer.

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  • Foundation

Step 4: Stem Wall Forms

Now that the footer has cured overnight, you can begin the stem wall. The stem wall is poured concrete reinforced with rebar. There are form boards for this pour.

The boards required are:

  1. 4pcs: 14’ 1”x6” (hardwood)
  2. 4pcs: 12’ 1”x6” (hardwood)

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  • Scaffolding

Patrick

The boards required are:

  • 4pcs: 14’ 1”x6” (hardwood)

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  • Tool List

Bob and Mac + Patrick

Ladders, Hand truck, Dollies

Scaffolding frames and planks

Some standard number of regular tools? Hammers, screwdrivers, chisels, rasp, plane, wire cutters, extension cords, lamps, etc.

Portable table saw, Drill press, Chop saw

Work Gloves, Helmet, Safety glass (polarized preferred), Steel toed work boots, lifting belt

Cordless tools: Circular Power Handsaw, Impact Driver, Screw Gun/Drill

Bit Kit (Various Drill bits, Several Philips head #2, Various Torx head bits)

The following videos will list carpentry & masonry tools list ~ here are some necessities.

Carpentry: Tool Belt/ Apron and HD bag to carry tools, 16-20 oz Estwing Frame Hammer, 30 ft 1” wide measure Tape, Speed Square, Torpedo level, 4ft aluminum magnetic level, Chalk line, Line level, 3/4” Chisel, Wire & side cutter, Tin Snips, Needle nose pliers, Cats paw, Flat bar, Razor Knife, Japanese Saw, Flat /half round file,etc...

Masonry: Apron, WP Gloves, 14”x 5” Stainless Steel Trowel,SS Bucket Trowel, Masonry Brush, Aluminum/Plastic Hawk

Here are some youtube videos that will cover basic carpentry and masonry tools. In regard to masonry tools i thought the last video here covered most tools needed

Https www.youtube.com/watch?v=Eer2xYAkS5U

https://www.youtube.com/watch?v=sbRoBrdYaRA

https://www.youtube.com/watch?v=AHau

https://www.youtube.com/watch?v=9V-bl3gsQdc

https://www.youtube.com/watch?v=TkXl-GaVV_E

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  • Workflow Optimization

Patrick

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  • Mesh and Stucco

Pieter, Bob & Mac

Stucco / Earthquake Basket Method

In order to further reinforce the block structure against earthquakes, wire gauze and wire mesh were embedded into the walls to contain the structure in a ‘basket’.

A narrow gauge wire gauze was laid on top of the cement foundation square with about a 4” overlap on both the interior and exterior side.

When the bricks were laid, short lengths of small gauge wire connectors which were about 20” in length were placed at intervals of about 18” apart laterally on alternating courses of bricks, vertically. These wires would be used to secure the larger gauge ‘chicken wire’ sheets to the structure on completion of the bricklaying.

The optimum design for these small gauge wire connectors was to twist two together in the middle and splay the two ends apart.

The chicken wire was applied in the largest overlapping sheets possible, and secured with the connectors which protruded from the bricks on both sides of the wall.

Note: the wire mesh/chicken wire should be installed as tight as possible to the wall. No more than ½” (finger thickness)away from wall. Anchored securely w/wire ties.

Here are some youtube videos to illustrate professional applications.

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  • Mesh and Stucco

Pieter, Bob & Mac

The intention was to keep the chicken wire tight and not more than about 1cm (a finger’s width) away from the CEB’s. It proved to be difficult to keep the chicken wire at the requisite distance from the CEB’s as some ‘bubbles’ formed which would make the stucco application uneven and unstable.

In the end it was necessary to revisit certain areas and affix the chicken wire closer to the CEB’s using either staples (0.5” or 0.75”) or 3” screws with washers where the gaps or movement were at their largest. Ultimately, the chicken wire was fixed securely enough and proved to be ideal for the stucco application.

Stones were placed along the top walls and under the chickenwire in order to better integrate the walls with the bond beam when poured.

Prior to the application of stucco, the walls needed to be thoroughly wetted to assist in the adherence of the stucco to the wall. Water was applied by either throwing water from buckets or, more optimally, using a hose and pressure washer.

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  • Mesh and Stucco

Pieter, Bob and Mac

Stucco was applied using one of two methods: a hawk (flat board with a handle) and a trowel was used to push the stucco onto the wall and smoothed over the area, starting from the base and working upwards to the top of the wall on both the exterior and interior walls, or a more rapid method of ‘throwing’ the stucco onto the wall very rapidly, and smoothing quickly, but this appeared to be a more wasteful method unless the stucco which fell to the ground was re-used.

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  • Walls

Marcin

To build the walls, start with 4x6x12” CEB block. The block should be placed as close to the house walls as possible, to reduce the amount of movement by collaborators.

To build straight walls, we found that using string is difficult with a large group - as someone is likely to move the string or it gets hung up on some protrusion. Historically, unless there is only one or two people laying, strings have not worked.

So we used wall forms. A brick stop board was screwed into or hung from the corner posts of the wall forms. The wall forms were quite a build project in themselves.

Once the forms were used effectively, it took only about 4 seconds to lay each slurried block. Workflow document was one person passing slurried block to up to 2 layers.

The challenge was moving the forms up.

  • We had long overhangs from the laying forms on each corner - as we were using purlin wood that we couldn’t cut as we would use it later.
  • Due to the hardwood used - some screws stripped and we had to cut them off

Learnings:

Forms for the brick stops were difficult to build, and they were not easy to move up.

Solutions could be making a better brick stop design - or reducing the number of people laying block so that string actually works. For example, a single layer on each side, fed by a support team of slurry makers, block carriers, snd block dippers in slurry - this could go really fast. We have seen rapid block laying

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  • Slurry Feed To

Walls

The overall workflow from earth, water, cement to slurry was:

  1. 5 gallon buckets are used to fill the 55 gallon drum, about half water, half earth. Water first! Both for cement, slurry, and stucco. It’s about not letting materials settle at the bottom. Then about a gallon of cement per 55 gall (about ¼ bucket).
  2. Tractor augers the mix
  3. Remove auger, then remove Buckets.
  4. Buckets are carried over to walls.
  5. Initially we started treating slurry as mortar, but then switched to slurry dipping and no mortaring.
  6. Wheelbarrow is easier to dip bricks in.
  7. At the end - we let it dip and rip! No mortar, just think of dip, with thin slurry layers so courses don’t get uneven. Look at those smiles:

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  • Bond Beam

Marcin

The bond beam is a reinforcing structure on top of the 15-course (7.5 feet tall) CEB walls. This structure has

The bond beam in the CEB Microhouse build was concrete. The concrete formula was

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  • Slurry Mixing

Joe

  1. Mixing - Slurry Mix
    1. Materials
      1. Mixing Machine - Tractor with Auger
      2. Container - 55 gallon drum
      3. Dirt/Earth
      4. Portland Cement
      5. Water
    2. Method
      • Set up 55 gallon drum and tractor with auger so that the auger can reach into the drum
      • Start adding materials to the drum.
      • Initial recipe
        1. 5 parts dirt
        2. 3 parts sand
        3. 7 parts water
        4. ½ part portland cement
      • This is not a science - start with the initial mix recipe. You are looking for a consistency that is like a ketchup or a bit more watery. It needs to not be “morter” it should run like watery ketchup.
      • When mixing the recipe changes to only adding more water and dirt and a bit of portland cement to get the right consistency. Sand stops being added as it does not play the most important role in the mixing of the Slurry.
    3. Suggestions
      • Create attachment for the auger that better mixes the slurry. An attachement that will act as a mixing paddle int he 55 gallon drum. This can be welded.
      • Ensure that the bottom of the Auger and the bottom of the drum are protected from each other. We punched a hole into the drum with the auger and made it not usable.

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  • Concrete Mixing

Joe

  • Mixing - Concrete Mix
    • Materials
      • Mixing Machine - Cement Mixer - Gasoline
      • Portland Cement
      • Aggregate - Gravel
      • Sand
      • Water
    • Method
      • Initial Recipe (5 gallon buckets were used)
        • 5 parts Aggregate - Gravel
        • 4 parts Sand
        • 2 parts cement (1 bag - 42kg)
        • 1-2 parts water
      • Use your discretion with the amount of water. Water will make the mix too loose - which will weaken the concrete over time
      • We added water first, then gravel, then sand, then cement - the goal being to have the mixer do the mixing faster. After trial and error the order above worked the best for mixing quickly without over taxing the motor.
      • The mix should be quite coarse, not runny at all. Remember the phrase that you place concrete, you do not pour it.
      • Water is the final ingredient as well as the first ingredient - add very small amounts at the end to get the right mix consistency.

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  • Stucco Mixing

Joe

  • Mixing - Stucco Mix
    • Materials
      • Mixing Machine - Concrete Mixer - Gasoline
      • Portland Cement
      • Sand
      • Lime
      • Water
    • Method
      • Initial Recipe (5 gallon buckets were used)
        • 6 parts sand
        • 1 part lime
        • 2 part cement
        • 1-2 part of water
      • In the mixer add a water, then sand, then lime, then cement
      • Continue to add small amounts of water to get the mix to the correct consistency. You are looking for a wet, slightly runny. You should be able to throw the stucco at the wall can get it to stick as in the photo.
      • Once you get the consistency that you like you empty the mixture into a wheelbarrow and get it to the Stucco Crew.

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Rake Studs (support for outer Trusses)

Rake Studs

Due to materials and time we used less than the designed quantity

Sapodilla wood

This wood varied in dimensions

Correct angle cuts did result in gaps. Slide rake studs to best fit.

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Rake Studs continued

Inside view of rake studs

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Rake Studs continued

Screws go in at 45 degree angle

Some of the wood split when installing screws in.

To prevent splitting the wood, drill holes first.

Two screws each side, top and bottom (8 total per rake stud)

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  • Bill of Materials

BOM Link

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  • CAD

Full files available in Sweet Home

3D and FreeCAD.

CAD Link

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  • Tools

Tools used to build

Minimal tools are required. These are also found in the Bill of Materials.

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  • Build Instructions

Modules