… starting a new phase of life.
Since we are doing all the prep work ourselves for the slab foundation, we also did the installation of the rebar for the foundation. We did get some help from a couple of local construction workers who worked with us for an hourly wage. That helped a great deal and made the work go much more quickly. The entire family did learn how to wire rebar and how to insert support rebar for the footers. Here are a few photos of the process:
This week has been a very hot and tiring week of plumbing work. After trenching the main lines for the plumbing plan (6″ wide and up to 59″ below the surface of the slab as the trenches sloped toward the septic tank) the real work could begin.
We began by taking the difference between the elevation of the slab and the depth of the entry pipe into the septic tank. That difference was 59″. Since the ground slopes toward the septic tank, there was a natural slope that required us to dig less deep trenches on certain parts of the foundation.
The distance from the farthest fixture to the septic tank was approximately 140 feet. Using a combination of 1/4″ slope for the 2″ pipes and 1/8″ slope for the 3″ pipes, we were able to lay the initial pipes fairly deep below the slab and then slope the drain and branch drains toward the septic tank.
Using a riding trencher ditch witch with a 6″ wide trencher, we dug the trenches. It is critical to lay out the trenching plan to avoid driving over trenches and collapsing the sides. It is also critical to use string lines and exact measurements on the form boards to insure your trenches are placed in the proper locations. We further used intersecting string lines (again with exact measurements) to mark the locations of fixtures within the foundation. Failure to locate these exactly will result in toilets placed too close or too far from walls or waste and drain pipes that do not exit the foundation in the center of a wall. This is extremely critical; measurements should be taken multiple times, string lines placed and rechecked before and after placing fixture location.
A few things we learned…
To avoid leaks, you cannot kink pipes at intersections and no pressure can be placed on a fitting. Blue glue can help with sealing minor seapage during the pressure test (apply, let dry for 2 hrs; reapply), but will not stop a leak. A leak will require you to cut out the offending fitting and replace. (Don’t ask how we know this — ).
Make sure when you are building your fittings, make sure you don’t work yourself into a corner and find that you have two sections that need joining and no room to pull the lines together for the joint… leave yourself room for mating up different branches of the system by working in the best sequence to allow room to maneuver.
The good news was that, with a few changes, our rough-in plumbing inspection was a success. The local inspector came out and did the inspection with the water test yesterday. He complimented the work, but required us to make some changes on the design because we used the wrong code book. Apparently, the international standards (which we used) are not acceptable. The local inspectors use the universal standards, which required us to completely rip out the fittings for one of the bathrooms (and a couple of other individual fittings) and lay it out differently. Finding out this information in advance would have saved time and fittings…
After this final work to finish the changes, we’ll be able to cover the plumbing ditches and begin work on the rebar for the foundation. This makes us very happy.
I’m a bit slow in posting updates (we’ve been really busy!), but here is a panorama shot of the house with form boards in place.
I immortalized the final bit of footer cleanout with this video:
Just a quick post to let you see how the footers looked just after digging with the Ditch Witch. Since then, they’ve been completely cleaned out and form boards are cut… another update picture to come.
We decided to tackle our own foundation. The estimates we are receiving for much of the work on the house are in most cases double the cost of doing doing it myself. The cost for labor is very high, and sub contractors are adding a percentage on top of the cost of materials. As a result I have decided to manage my own monolithic foundation pour. I will do everything except the actual pouring of concrete. I have a sub who will inspect the pre-work, make recommendations for improvements, if any, and bring a crew to mash the mud into the holes and smooth it all out.
Lacking an experience in concrete work other than to watch it done several times, I turned to literature to learn as much as I could. I found the book, Foundations and Concrete Work, published by the editors of Fine Homebuilding, to be an excellent reference and source of information which ultimately boosted my confidence in tackling the job.
The book has sections dealing with; the basics of concrete, the basics of foundations, working with rebar, concrete tools, and information on various types of foundations. The book is more geared towards the northern tier where footers, stem walls and floor joists or basements are built. There was little on the peculiarities of the monolithic pour which is prevalent in southwest residential construction. I found the basic information to be be very useful. The section on the use of rebar and how to tie the various portions together was a great help. In addition the discussions of compacting soil was helpful with building the pad. Many of the techniques discussed in the section had a bearing on how we built up the foundation pad. I would recommend this book for the novice homebuilder and give it 4 out of 5 stars.
Now that the Ditch Witch work is complete, there is quite a bit of hand work still to be done on the footers. Cleanout of the remaining loose dirt, redistribution of all the augured dirt on the pad and cutting a 45 degree bevel on the inside top of each edge of the footer require some sweat.
Here is a drawing to illustrate the footer/slab plan:
Photos of non-cleaned out section of the footer:
Photos of cleaned-out sections follow. Note the 45 degree bevel on the inside edge. Adding that bevel increases the amount of concrete on the edge of the footers and reduces the stress points where the slab and footers meet.
The pad was so solid that a pickaxe was required to clean out the corners adequately. The key is to get the bottom of the footers cleaned out down to rock or virgin soil. Any non-compacted dirt in the footers can result in eventual settling and cracking of the foundation. Since the pad is already leveled, we are moving the augured dirt to the inside of the foundation to build the pad up evenly. We probably will not require any crusher fine fill, since we have enough fill dirt to build the pad up the 1″ or so needed. The form boards will be 5 1/2″ above grade, so building up the interior of the foundation another inch will still yield a 4 1/2″ thick slab. 4″ is the nominal thickness… any extra adds additional rigidity.
We will be using a long, straight board to pull the dirt on the slab level by putting a lip on the board and dragging along the form boards to achieve a level surface. We plan to sink several pieces of vertical rebar into the slab with the tops level with the form board. These will serve as a pivot point on the interior of the slab for anchoring the long board when pulling the dirt level on the slab. Photos to follow when we get to that point.
After a few weeks’ delay, we are back on track with preparation of the foundation. Friday and Saturday we were able to get all the footers dug with the help of a rented Ditch Witch. This machine will dig the 24” x 12″ footers using modern building methods.
Through planning the order of the cuts, we were able to minimize the amount of hand work that will be required to fully prepare the footers to support the foundation. We had to go through a slight learning curve as we began the work. Discovering the best way to keep the lines straight, using a two-person team to help with start and stop points, keeping the string lines free of the dirt piles and assisting with raking level the start points for each dig made the work go more easily and enjoyably.
We took a video of the first cut… the cut for the entry door of the house:
Lessons learned:
Now that the footers are rough-cut, we are in the process of hand-cleaning the ditches and evening out the additional fill-dirt from the cleanup.
Amidst a bout with kidney stones, extremely hot and windy weather, we finished our building pad and foundation lay out. I started by staking out a general layout of the foundation, placing corner stakes for the foundation in the location that we wanted the house to sit. This was not an exact layout just a general one done with a tape measure, stakes and string lines. Since we sit on 5 acres with no required set backs and no easements, I was not concerned with citing the corner of the house +/- ¼”. It was sorta a “looks about right” placement methodology. Had we been building in a subdivision, I would have used surveying equipment to place the foundation exactly in accordance with the plot plan.
With my foundation line in place, I used a Bobcat and removed the top few inches of top soil under the foundation and scraped away the vegetation around the foundation for several feet. The solid material under the pad has been undisturbed for millennium and we are about 16-24” above the first rock layer. My footers will extend, in most cases, through the soil and rest on the rock. Combined with rebar, 3000psi, fiberglass impregnated concrete; I think we will have a very solid foundation.
I then placed corner stakes for where I wanted the pad built up. I placed them 5’ on the outside of the foundation perimeter. That will give me a good buffer to work with when doing the trenching for the footers, and provide material to create a suitable run-off grade sloped away from the foundation. I then used the CST/Berger 800’ Dual Beam Rotary Laser to set a perfectly level string line at 6” above the highest grade. The lowest point on the pad was 6” below the existing ground layer.
I ordered more than 200 tons of fill dirt and with a Bobcat I moved layers of dirt around the pad, using the string lines as both a perimeter guide and a height guide. As I moved the dirt I ensured I compacted as I drove the Cat in reverse with a majority of the weight of the machine on a nearly level bucket. The weight of the Cat and bucket being drug across the dirt aided in compaction. It is essential to compact between layers (4-8” recommended depending on soil quality) rather than filling completely and then compacting. Such a manner will result in only the top 6-12” being compacted and the bottom layer rather “fluffy” Over time the ground will settle resulting in foundation complications.
After the boys finished school, the assisted me in getting a fairly level pad (+/- 2”) by running supplemental string lines across the pad. Wherever the string touched the pad it was too high so I removed some dirt. Where the string was above the pad, I added fill and compacted. I was surprisingly able to build a fairly level pad using this method. During the evening and into the next day, we sprinkled the pad heavily allowing the water to trickle down into the layers as best as possible to aid in further compaction. I rented a walk behind vibrating roller and ran across the pad at least 4 times resulting in an even greater compaction.
I waited for the top of the pad to dry somewhat to prevent the caking of mud on the rollers. My concrete sub and a very seasoned home appraiser both were impressed with the work. Since I had never built a pad before I wanted a few folks to look at it.
The next step was to accurately (+/- 1/8”) lay out the exact perimeter of the foundation so that the footers could be trenched and the form boards could be placed. I purchased the CST/Berger 800’ Dual Beam Rotary Laser to do the work. I figured rental on the device for as many days as I would need it for the pad, the foundation, interior work, etc. would begin to add up. It thought it would be well worth my time to buy it. It took me a while to learn the nuances of the device and make sure I was taking accurate readings and properly setting up the level. In the end I will have a lightly used, well cared for device that could be sold. I am certain this is a cost effective decision.
I established a system of string lines and batter boards which defined the entire perimeter of the foundation. I used conventional methodology for this task, relying on 36” steel stakes rather than wooden stakes, given the density of the ground. I took several diagonal measurements where possible to ensure everything was square. Given the dynamic nature of the perimeter, with lots of corners and 45 degree angles, taking the diagonal measurements was not easy. My worst measurement was 3/8” over a 60’ length. I was striving for ¼”, but moving one stake impacts several others. It’s not as easy as squaring a rectangle with four corners. I think I will leave well alone and refine the “square-ity” in the framing stage. Once I was pleased with the work, I used line marking spray to trace the outline of the foundation, which you can see from the image. The next phase will include trenching the footers and placing the form boards, followed by rough in plumbing.
This past week has been spent with various aspects of making life a bit more comfortable on the homestead. Such things as repairing a burnt out water heater caused us to learn a few new things(an error made by our electrician after power was supplied caused the tank to fill to only halfway, above which one of the heating elements burned out, shorted out the tank and began leaking).
We also began unpacking those things we will need during our stay in the RV and organizing things to allow some convenience. The bathroom inside the workshop is excellent… the washer and dryer are very handy… this is so much better already than the RV living we did during our evacuation from New Orleans after Katrina.
When we envisioned building ourselves, we really had not planned to do the site preparation ourselves, thinking it must be something to hire out. However, once we got the estimated cost of $7800 to build it up, we decided to put pencil to paper and see if that seemed reasonable.
After calling the local suppliers of fill dirt to compare pricing, getting information from them about compaction and delivery, we calculated how much fill dirt we would need to build up the pad to the desired 9″ or so. We also checked pricing on rental equipment and called up a brother in law with lots of dirt-moving experience. He provided some excellent tips regarding what type of equipment to rent, how to compact the dirt properly, etc.
After all this, we figured we could do it ourselves for less than half the cost. About $2400 in fill dirt ($11/ton in large loads; $16/ton for the last 15-ton load), and about $750 for a 3-day rental on the bobcat came to only $3150. We still need to rent the roller, but don’t expect that to be terribly expensive, perhaps no more than $150. On this first thing, we were able to save about $3500 by doing the work ourselves. Granted, it took a bit of time to master the technique of spreading the fill dirt evenly, so it may have taken an extra day of equipment rental, but it was still well worth the effort.
The work on preparing the site for building the house began on Monday morning with the renting of a bobcat for site preparation. Over the weekend, DH and the boys used the laser leveling gear to determine just how much slope there was to the building site. As it happens, it was only about 6″ total, so pretty level to begin with. After that, DH used the bobcat to scrape away the vegetation and dig the (very hard) surface off to prepare to add fill dirt.
The delivery of the fill dirt was very interesting. Arriving in very large trucks, they delivered 25 tons per truck (100 tons total) the first day… another 100 tons the second day and a final 15 tons in a smaller truck to finish off on the third day. On the second day, during the dumping of the load from the second truck, we had a bit of a scare.
The truck backed up very quickly, coming within 6″ of the RV. My not very excitable husband got excited and yelled at the driver to stop… just in time. I was filming at the time, so it is documented… the noise of the trucks are such that you can’t really hear my husband saying (as he walked away): “Boy, that was close!”
DH took time to teach the boys how to drive the bobcat… both of them thought it was great fun. No doubt their computer game skills helped them a great deal! We have some vids to post showing their skills… The first is of the oldest boy (13 years old), working the magic:
The next video is of the youngest boy (11 years old), at the controls of the Bobcat:
The pad has now been built up to a fairly level state, with extra space built-up around the edges to allow for porches, patios, etc. This weekend has been spent watering the pad in preparation for rolling to compress the soil further next week.