Tag Archives: caliche rock

How Long Will it Take to Erect My Post Frame Building?

How Long Will It Take to Erect My Post Frame Building?

This is a popular question posed not only by many potential building owners who are considering doing work themselves, but also by contractors who are considering erecting a building for others.

Before any question of construction time can be addressed, let’s eliminate one crucial variable –dirt. Time to lay out a building and dig holes depends upon so many factors. Is the building site level? If it is level, is your building’s prepared pad, actually large enough to place batter boards on? Sites “too tight” to work on will slow everything down.

October 30, 1996 when my company set a world speed record constructing a fully featured two car garage on site, we had a daunting task of it being under five feet from fences along one side and an end. And we still completed it in 31-1/2 minutes! Yes, minutes!

What is the site’s soil like? Soils with medium soil bearing pressures (1500-2000 pounds per square foot), generally are pretty good to dig in. Extremely sandy? Conical shaped holes will be created and they are hard to clean out. Lots of clay? When wet it sticks to everything, when dry it can be as hard as concrete. Head sized rocks? An auger will only pull up rocks up to one-half bit diameter. Limestone, granite, or caliche? If it sounds hard, it probably will be.

Available equipment type for digging holes plays a huge part in digging time as well. By hand with a shovel and clam shells is going to be much slower than a line truck with an auger.

So….putting dirt in our rear view mirror, we move forward (and upward)!

When I was running my own construction crews, we used to monitor carefully approximate amount of construction time it would take crews to erect our buildings. There were always some exceptional crews, ones who we would shake our heads at wondering how they built things so fast. One particular four man crew, would start on a 60’ x 120’ x 16’ riding arena Monday morning, and be in our office at noon on Friday with building done and collecting their payment. Their secret? They had worked together for so many years they did not even have to talk to each other on a jobsite. Each knew instinctively what to do next and what their fellow crew members were doing.

When I put up my first prefabricated roof truss assembly building, I contracted with them for roof steel installation. On this 60’ x 84’ building, I was almost disappointed when they completed it in under four hours!

Getting back to more average performances…. measuring person hours (yes, I had an all-female crew) to building value ended up being a fairly constant measure. Keeping in mind, this is all my crews did, so they had lots of experience They would assemble $120 of materials per person hour. Other than those few exceptional crews, this was a solid number to work from with a variability of about 10%.

For an average building owner doing their own work, I’d look at it taking twice as many hours, provided their “homework” of reading assembly instructions and reviewing plans for their next day’s work was done off actual construction time.

Can you construct a post frame building kit package yourself? Most probably, and as long as you are physically capable, will read and follow instructions, it will be a beautiful building. Should you build it yourself? Assuming a $24,000 building kit, plan on around 400 person-hours. Hired out, it is probably reasonable to spend roughly $12,000 for labor. Obviously this dollar amount will vary greatly from locale to locale. Factors such as distance to travel to a jobsite and costs for insurance weigh heavily into this equation. If a labor quote is $12,000 and you can build it in 400 hours, you have “paid” yourself $30 per hour.

Besides cost savings, there is a satisfaction of having created your own beautiful building and chances are –the outcome will be better than having hired it to be done!

Pole Building Holes in Caliche Soil

One of our clients is preparing his site in order to dig the holes for his new post frame building kit. He happens to live in an area of Washington State, east of the crest of the Cascade Mountains, which would be best classified as being high desert. He has encountered the bane of excavators in the more arid regions of the American West – caliche.

Our client reports: “After completing site excavation, I’m left with several areas that have caliche rock where I need to dig column footings. It’s a very hard, concrete-like layer of calcified sedimentary rock and I’m wondering if you guys have suggestions on how to dig through this most easily. The best idea I’ve come up with so far is a skid steer with a jackhammer to break through the caliche and hope that it’s not more than a few inches thick. I’ve also read that some people have had luck with a mounted auger that has a rock-drilling bit. Wondering if you can recommend any preferred methods that you’ve come across as I’m currently expecting that I’ll need to deal with this rock for at least half of the 28 column holes.”

What exactly is caliche soil?

According to the sum of all human knowledge (aka Wikipedia):

Caliche (ka-lee’-chee, or sometimes klee’-chee) is a sedimentary rock, a hardened natural cement of calcium carbonate which binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semi-arid regions. Caliche is also known as hardpan, calcrete or duricrust. The term caliche is Spanish and is originally from the Latin calx, meaning lime.

Caliche is generally light-colored, but can range from white to light pink to reddish-brown, depending on the impurities present. It generally occurs on or near the surface, but can be found in deeper subsoil deposits, as well. Layers vary from a few inches to feet thick, and multiple layers can exist in a single location.

My advice on digging through caliche

Back in the day I was a post frame builder in your neck of the woods and we did hundreds of buildings which ran into caliche. We finally just invested in a ram hoe attachment for our skid-steer and found it was able to get through it every time. You should check in with your local equipment rental companies to see what they have available in this realm. You might also contact the local utility companies, as often they have equipment sitting unused and will come drill holes for a nominal fee.

One Might Expect I Would Call This Good

However I am thinking there must be another, maybe even better way. Well, thanks to the internet, I have found the poor man’s water jet/drill (as shown in the photo).

Here is how it was built and used:

“Needing to dig a series of post holes in my hard (caliche) dirt was a job I was not looking forward to. Even the caliche bar protested the job and merely bounced off the stuff. So I was either going to do it the hard way with good old blood, sweat, and blisters, pay someone to dig the holes for me, or come up with a better way.

I went to my hardware store and purchased a 30″ length of 1/2″ black iron pipe, a 1/2″ to garden hose adapter, a ball valve, a 90* elbow, a 1/2″ to 1/4″ pipe thread reducer, and a 1/4″ barbed nipple. Screw these all together and you have something that looks like the photo.

Attach the hose, turn on the valve and feed into the ground. I sunk this to the valve in less than a minute, which amazed me because this dirt is truly like concrete. For bigger holes, just drill a series of holes next to one another. The water tends to soak into everything between, and you can use a post hole digger to make your hole now that it’s not bouncing off the hard stuff.”

Have caliche on your new post frame building site? there are solutions!