After several weeks’ worth of preparation (I had no idea there was so much involved before we did this ourselves), the foundation pour happened! Two nights before the pour (Sunday evening), we got a wonderful heavy rainfall. We were concerned at first that it might do damage to the trenches, but all was well. Our concerns over the muddy road were also unfounded.
Footer between garage and house
Then Monday evening, we got another heavy rainfall (have I mentioned that we have not had any rain since May prior to this?). Again, we were concerned over the road conditions and the possible damage to the trenches. At 5:05 a.m., the subcontractor who would be doing the actual pour pulled into our drive. He said all was well with the road and the trenches, so the pour was on! Soon after, his son, cousin and two other workers arrived. At just after 6:00 a.m., the first concrete truck arrived.
Truck #2 arrivesPouring the footersPouring the house portion of the slab...
They began with the footers, starting with the wall between the house and garage. Since there is a step-down between house and garage, that portion needed to dry a bit before the lower garage level would be poured. Pouring it first allowed the braces to be removed before the garage pour.
"J"-bolts insertedCorner before finishingDoorway from Garage to House
The subcontractors worked really well together and did a great job. If you are interested in getting concrete work done in SE New Mexico, we would highly recommend them (Samuel Castro 575-420-6615). We were also very happy with the service offered by Roswell Ready Mix (575-622-1186) . They have a large fleet of trucks and were able to handle the timing required for a good steady supply of concrete for the subcontractor.
We chose to have 3000 psi concrete plus the added fiberglass to add more strength to the foundation. Since we are considering doing a concrete floor stain, we want to try to avoid even small surface cracking as much as possible.
In order to protect the plumbing from the concrete during the pour, after the pipes for Showers, Toilets and Bathtubs are cut to 1/2″ below the finished surface, sealed with duct tape and then protected with cardboard. For the toilet drains, three layers of cardboard is fitting around the PVC and one layer of cardboard is cut to size for the top. For shower and tub drains, a cardboard box is cut to the correct height, filled with filldirt and sealed shut. A small amount of fill dirt is placed on the box flaps to hold its position. This allows the concrete to be poured and smoothed right over the tops of these drains. After the pour, the openings can be accessed by chipping away the small amount of concrete on the tops.
Measuring height for the cut..Marking the pipe...Cutting the pipe...Cut to correct height...Duct tape top...Completely sealed...Box cut to correct height...Fill with fill dirt...Level fill dirt
Toilet drain dab-outs are slightly different, so a separate set of photos also follow:
Toilet drain Cut toilet drain to height...Duct tape...Check height...Cut box to correct height using excellent multitool.Using the saw as a straight edge...Wrap cardboard around toilet drain.Three layers of cardboard...Cardboard cap for good measure.
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:
Nearly all rebar in place...Corners bent without Cheater pipes.18" apart Rebar meets footersLaying out the rebar
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:
Footer/Slab Details
Photos of non-cleaned out section of the footer:
Lots of pickaxing still required...No beveled edge yet.
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.
Cleaned out cornerNote string line -- right on.Cleaned out with beveled edge
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:
Place the batter boards at least 8 feet out from the edge of the cut. This allows ample room for the Ditch Witch to maneuver to the end of each cut, minimizing the pickaxe work to be required later.
Make a practice cut on a location well clear of the foundation. This allows you to shorten the learning curve on how to line up the blades and keep the lines straight on the foundation.
On cuts that intersect another cut, don’t cut the first cut completely to the edge. The second cut can remove the material without the risk of caving in the sides.
Wherever possible, orient the Ditch Witch so that the auger is on the inside of the foundation. This will move the majority of the dirt to the inside of the foundation to use for additional fill.
Remember to use sunscreen on your neckline. I ended up with a sunburn there. Face, arms, hands were all fine… just the neckline got scorched.
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.
String lines, batter boards and orange marking paint define the outside edges of the foundation.
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.
