# foundation work



## peteo (Jan 8, 2011)

I need to ask a question that I should already know the answer to...

I have recently talked to a few prospective clients about digging foundations. I havent dug one in a long time, almost ten years. the last few that I did do were for precast walls so everything was set to one grade with a pit for the sump. my question is do I dig it the same way for a block foundations or do I need to dig down for the footer area as well? I am not sure how they do it anymore since I havent done one in so long. also, I know bid questions are generally frowned upon but I took a job digging some footers for a guy and I gave him an hourly rate. do you guys generally go by the hour or a bid price for footers? the job is for an addition to a garage. thanks for any advice you guys give.


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## greg24k (May 19, 2007)

Your surveyor should have the basement floor elevation on the survey. If he don't, it is very easy to figure out what depth you need to be i.e, If you have 8' basement with a 10" footing and you have a 24" window, you want the window to be at least 6-8" above final grade elevation. 

Keep in mind about the water table in the area, good idea to have a water table test done.


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## rino1494 (Jan 31, 2006)

I always figure where I want top of wall to be, then dig down the depth of the walls plus footer. For example, if at the garage, I want it to stick out 1 course of block on a 12 course foundation. I'll set up my laser, shoot that corner and lets say the laser was 1' higher than the the ground, I am therefore 4" higher than the top of wall. You would then have to dig to a depth reading on your stick 9' with a 8" footer.


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## JustaFramer (Jan 21, 2005)

So what you are saying is you have no control? You need to establish a control hub/mark and then you can establish your depth.


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## CanDoExcavating (Feb 11, 2010)

Dig the entire basement to footer depth, set your height so you have plenty of fall to all sides and make sure you have enough fall for your sewer. We generally dig sewer and water in first then you'll know the answer to that question. I usually set pricing off of cubic yards for the basement, garage footings by the foot, as well as walkout footings. As for actual prices only you know what your costs are good luck!


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## greg24k (May 19, 2007)

I don't know how it is anywhere else, but here whether it's required or not, before I build a house on spec or for a customer, I have a water table test done by engineer to make sure my basement floor is always 1' above the seasonal high water table if that condition is present. That will give me a dry trouble free basement. Next I have my building staked out by a professional surveyor and if high water table is present, I give all that information to my surveyor and I get stakes on each corner with elevations and a cut sheet with a basement floor elevation. When I am in the field and getting ready to dig, I will do minor adjustments to the foundation if needed to accommodate larger windows and adjust the garage floor height to get a pitch for the driveway water run off,etc. It don't get anymore simple then that. 

When excavating, I go 1 1/2-2 buckets (depends what bucket size is used) on grade for the footing, 8" in and the rest out on grade and lift inside the basement 6" up if it's a 10" footing, so you have 4" for the stone under the floor and you ok for the perimeter drainage depth outside the footing, for the pipe,stone and you can work around i,e. to do foundation paging and waterproofing.

I don't know how you run your sewer before you excavate the basement, I never in my life seen this done that way. Even if a sewer is going under the slab, you put the PVC sleeve under the footing, do the foundation and run the sewer after,stub it out before you do the basement floor. If the W/S going through foundation, I put the sleeves through the foundation wall, this way when we run water and sewer to inside the house, the sleeve already through the foundation wall and the plumber don't have to bust through the block and do the patching. Saves everyone time.


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## CanDoExcavating (Feb 11, 2010)

Here in south dakota Sioux falls area they want gravel or select fill between the footings for drainage, just one of those local things it allows the ground water to get to the drain tile very quickly. As for the sewer and water it's way easier to dig it in first, it allows you to see the stub in and curb stop as you are digging to them. Quite often we have water pushing up the rock they put around the sewer stub, by doing it first it allows you to see it immediately pop the cap and gives you time to get pump in before your trench walls become water soaked and their stability compromised.


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## peteo (Jan 8, 2011)

thanks guys! much appreciated. yeah we always dig our sewer and water in first and then do the basement and garage. I just couldnt remember if I was supposed to cut the whole floor to footer depth or not. thanks again. :thumbsup::clap:


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## dayexco (Mar 4, 2006)

when i'm faced with such a dilemma..i do one of 2 things. i look at the blueprints, or if none are available..i ask the guy pouring the footings what depth he wants them dug. typically solves the problem in short order.


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## greg24k (May 19, 2007)

Well Mason is not the person to ask, GC or who ever is in charge should be asked that question and should have an answer, unless you dealing with a surveyer direct. When I have my lot staked out, and if I don't dig myself, my excavation guy will ask me if there is any changes...if not he got the cut sheet,all he has to do sets up the laser and set his depth and digs the basement. 
The elevations is not something you guess or dig as deep as you can or want, if you dig to deep, you could have major problems or back charges.

They set elevations according to surround area grades, final drainage grades, home elevations on adjoining properties, etc.


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## rino1494 (Jan 31, 2006)

greg24k said:


> The elevations is not something you guess or dig as deep as you can or want, if you dig to deep, you could have major problems or back charges.
> 
> They set elevations according to surround area grades, final drainage grades, home elevations on adjoining properties, etc.


Maybe that is what is required of you in NJ. We've done over 500 houses in the last 20 years and never had a plan with a FF elevation. We layout the house with the GC within the set backs, make sure it is square with the road and set up our laser and shoot grades. GC leaves and we start bailing dirt by 9:00. We always go over the grades with the GC, that way he knows if there is dirt to be exported or imported. No engineers, no surveyors. It isn't rocket science.


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## CanDoExcavating (Feb 11, 2010)

They set elevations according to surround area grades, final drainage grades, home elevations on adjoining properties, etc.


That's what we do but sure don't need a special sheet. Surveyor stakes I set height and definitely not the foundation guy at least here in the Big city LOL. Commercial jobs are a different story surveyor sets height using a nearby benchmark


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## greg24k (May 19, 2007)

rino1494 said:


> Maybe that is what is required of you in NJ. We've done over 500 houses in the last 20 years and never had a plan with a FF elevation. We layout the house with the GC within the set backs, make sure it is square with the road and set up our laser and shoot grades. GC leaves and we start bailing dirt by 9:00. We always go over the grades with the GC, that way he knows if there is dirt to be exported or imported. No engineers, no surveyors. It isn't rocket science.


Who set's the corner stakes, or you just pick a spot on the lot put 4 stakes, square them off and start digging?

How do you know where your property line is if there is no stake out?


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## greg24k (May 19, 2007)

CanDoExcavating said:


> They set elevations according to surround area grades, final drainage grades, home elevations on adjoining properties, etc.
> 
> 
> That's what we do but sure don't need a special sheet. Surveyor stakes I set height and definitely not the foundation guy at least here in the Big city LOL. Commercial jobs are a different story surveyor sets height using a nearby benchmark


It is not a special sheet...you never heard of a cut sheet with a floor elevation? and I never said foundation guy, someone else said it...I hope you dig better then you read :thumbsup:


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## rino1494 (Jan 31, 2006)

greg24k said:


> Who set's the corner stakes, or you just pick a spot on the lot put 4 stakes, square them off and start digging?
> 
> How do you know where your property line is if there is no stake out?


Most of the work we do are in developments and the property corners are marked. Typically, on a older piece of property, the owners will have it surveyed. Doing a customer home, the GC usually meets with the HO to determine house placement and elevation. When we show up, we layout the foundation based on what the HO and GC has determined. On a spec, we meet with the builder and go over house placement and elevations. 

We stretch strings along the front and sides of property line and measure to make sure we are in the set backs. We always lay out the houses because we have dug some in the past that were wrong and we had to come back to fix them. We get paid for it, but it just the idea of doing things twice. 

That is pretty much the norm here.


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## mudpad (Dec 26, 2008)

Here is a picture of how NOT to do it. This is a new house being built between my jobsite on WKU campus and my little home away from home apartment. I couldn't believe what I was seeing. While I am a block away arguing with a geotech and structural engineer about whether "fractured" rock will bear the required 10kips or if I have to dig down through the fractured and verify solid rock, this guy is pouring footings on topsoil, with roots running thru it, 6" thick in places, no rebar, step downs anywhere from 3" to 11" (I measured some just for giggles). some of the step down bulkheads were embedded in the concrete so he just broke em off or left them in place. 

Believe it or not, the mason showed up the next day and did a pretty decent job of laying the foundation walls. He had to cut almost every block in the first course off the footing.


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## rino1494 (Jan 31, 2006)

If I dug a footers with those many steps, the mason would shoot me.

What is code for frost depth in Tn ?


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## greg24k (May 19, 2007)

rino1494 said:


> Most of the work we do are in developments and the property corners are marked. Typically, on a older piece of property, the owners will have it surveyed. Doing a customer home, the GC usually meets with the HO to determine house placement and elevation. When we show up, we layout the foundation based on what the HO and GC has determined. On a spec, we meet with the builder and go over house placement and elevations.
> 
> We stretch strings along the front and sides of property line and measure to make sure we are in the set backs. We always lay out the houses because we have dug some in the past that were wrong and we had to come back to fix them. We get paid for it, but it just the idea of doing things twice.
> 
> That is pretty much the norm here.


Is what I thought you have to have something staked out to get the building location, thanks for clearing that up.:thumbsup:

Around here is a little different. We never place property corner markers. When the lot is cleared and top soil is stripped, surveyor comes out and stakes out 4 corners and offset stakes 10' off. Then we string it and mark it, then dig it. Mason comes next using the same stakes, pulls the line and drops the foundation corners, pulls the string and sets his forms.
When the house is sold, and HO requests property corner stakes, I charge about $150 per corner stakes.


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## CanDoExcavating (Feb 11, 2010)

Sorry Greg the foundation dig was not at you. As for the cut sheet it would be a special sheet for a house here. All our foundations are layed out with a total station marking each building corner, garage corners, and building control lines plus lot corners. As far as all gc's are concerned it is not the excavators job to stake the house. Oh and thanks for pointing out my mistake by the way had you been paying attention as YOU read you would have seen the post I was referring to. Thanks for playing!


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## greg24k (May 19, 2007)

CanDoExcavating said:


> Sorry Greg the foundation dig was not at you. As for the cut sheet it would be a special sheet for a house here. All our foundations are layed out with a total station marking each building corner, garage corners, and building control lines plus lot corners. As far as all gc's are concerned it is not the excavators job to stake the house. Oh and thanks for pointing out my mistake by the way had you been paying attention as YOU read you would have seen the post I was referring to. Thanks for playing!


No problem at all Bro... Thanks for clearing that up as well :thumbsup:


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