Geotechnical Testing for Home Construction: Proof is Possible, but It Hurts on our House Build

Geoff Hebner of Padstone Geotechnical Engineering returns to run a simple test on the dirt before pouring concrete, and Corbett finds out he’s not as slick as he hopes.

[badlandskid]

Awesome video and poignant lesson. I really learned to appreciate the customers who requested geotechnical engineering on their projects. It may make your work more complicated initially but not as complicated as dealing with lawyers and hundred dollar words later.

[wayneblanchard]

Your pain. My gain. At least knowing about soil stability under a footing which I may never need to know. I still LOVED this. The pointy thing went in to easy but saved you thousands. Thank you for walking the walk.

[markbenn]

You have a great attitude about this👍🏻 you’ll be rewarded for chasing down the facts

[ernieforrest]

A common procedure in some areas of the country due to type of soil etc.
In some cases a wider footing is required, others might include a deeper excavation into more stable soil.

[ek]

You are lucky to count with the knowledge of a soil consultant.

Most important part of a building is the foundation.

This quick consultation will save you money down the road in very expensive repairs.

[lubierjaramillo]

Preecise recomendation to set a solid bed of rocks prior to proceed with the foundation👍👍

[EchoTangoSuitcase]

One of the things that I learned along the way is that over-engineering stuff at the beginning of a project is often cheaper than having engineering consultants come in.

Which is NOT an argument against engineering consultants. It's an argument in favor of "over-building".

For example, and this is going back BEFORE the day recorded in this video... (Also, taking into account the rock.)

I probably would have excavated down a couple of feet and about twice the planned footer width. and blended the materials with portland cement. There are a couple of ways to do it. One way is to shovel the cement right on top and blend using a rototiller, another is to actually use a cement mixer to blend it dry, then wheelbarrow it over to the footer area and dump it in before raking it out. I would likely have chosen the latter method since it allows my to layer in some Geogrid. Everything gets compacted with a jumper or vibrating plate. That portland cement trick is an old soil correction hack that I think goes back to the 19th century. Lime also works. Mainly, you want to keep organic material out. If you think you have a lot, dilute the soil with sand before adding the cement or lime.

That's quicklime, by the way. Hydrated.

Lime is better for fine grained material like clays and silts, cement for coarse grained soils with a high sand content. Either way, when I've done it I was aiming for 5% - 10% of the total material.

There are actually formulas and specific guidelines for this stuff, but I generally just went seat-of-the-pants with it. The guiding principle was the "Nuke it from orbit" school of thought. Nobody ever complains when something is TOO strong or solid.

[patrickcummins]

Thanks guys. I just started a job as a field tech. Lol, I already use a 5/8ths piece of rebar to use as my rod to determine the footings.

[DinkyDoughnut]

Good shout, I like the explanatory views and what is gonna be done in compacting the soil and the reason why the windows or doors are not opening. now I know why a property which has excess ground movement.

[pats]

My house, in virginia would not stop moving. Drywall cracking, door sticking, cabinets pulling away from the wall were the indications something was wrong, it's the soil. The house was built on expansive soil, having an uplift pressure of 900lbs per sq ft, one level ranch on full basement 1600sqft. The builder and building dept failed to follow the expansive soil policy. 1.5 years of battling the building dept and builder and still not done with the repairs. My geotechnical firm designed the removal of the backfill, replace with gravel/ topsoil and 19 helical piers. By the time it's over, the cost, estimated $50k. The only way to tell if the soil(clayey soil) is good; have the soil tested for expansiveness. As far as the video goes, the point is; verify the foundation soil, to do that you need a qualified geotech to examine the soil, and it shows that.

[geofreak]

The Durham-Geo Slope Indicator static cone penetrometer probe has q gauge on it that actually gives q bearing strength reading and is more reliable than just a static probe

[kylehamilton]

I worked with Geoff on a large retaining wall south of Atlanta. Great guy!

[questioneverything]

I have seen push rods with gauges for soil testing, takes the guess work out.

[FourthWayRanch]

Should have done that before you made the forms. That county doesnt require soil test?

[lousertich]

I have done many basements and see that you are there every day with the bad weather . I really do like the fact that you are out there kicking the shit with the workers and taking on the tough results from learning the proper way . Radon has been a factor in my stint as a Professional Laborer because of buried trees and ? Now with the form a drain you said it will be vented through the roof? My first thought was? Are the drains running into a crock with a sump pump? in the house or are they flowing with gravity away from the house and if it does run into a crock how does vent through the crock ? I have only vented for radon on the outside of a dwelling not inside . Still learning ! after retirement.

[terrapuraregenerative]

Are there some tests that can be done by yourself before to call a specialist. Like for the soil health assestment?

[jameswright-]

how much do geotechnical engineers charge for doing the foundation soil test bores which should include wet and dry density, compaction, moisture, bearing capacity and as you say "quantifiable high performance ."

[tinkermouse-scottrussell]

I received a lot of good information from this video thanks for taking the time to share it with us.
From Elliot Lake Ontario Canada.

[AndyHoltOutdoorUniversity]

So glad you’re sharing the real world. Lots of knowledge to be gained by understanding the details.

[garrettp.]

How does walking on the dirt "loosen" the dirt?? Also, wouldn't rain further compact the soil?