hottubbrad
Registered Users
Posts:5
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| 06/05/2008 1:04 PM |
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Having just moved from the West where we have dirt (and plenty of it), I am now building the footing for my new home on bedrock. The issue is the bedrock is uneven (about 15" from one end of the house to the other). What is the proper method of pouring this level?? Initially, I thought step footings, but you can't cut steps into stone for under your cribbing (to limit concrete waste).
What is the best method without wasting too much concrete? My ICF block are 18" high and the first course will be cut in 1/2 to 9" high.
Thanks.
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Paul Stevens
Registered Users
Posts:143
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| 06/05/2008 4:13 PM |
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Don't build footings, carve your ICF straight to the rock. Where are you building? Sounds like the Canadian Shield to me. I can give you a better understanding if you want to give me a call. Depending on where you are maybe I can give you a hand. I am in Barrie, Ont.
705-333-1091
Paul |
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Paul Stevens
Registered Users
Posts:143
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| 06/05/2008 4:15 PM |
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| Try pour footings at your corners so that you have a solid starting point. try to have them either 18" or 9" incremants that way you can level as you go, knowing at which height you are supposed to be at , like I said before, call me and I can talk you through it easier!!! |
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Chris Johnson
Registered Users
Posts:341
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| 06/05/2008 7:55 PM |
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| Don't forget to drill and epoxy vert bars into the rock |
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Chris Johnson - Pro ICF
Napa, CA
Come for the wine, Stay for the ICF work |
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Paul Stevens
Registered Users
Posts:143
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| 06/05/2008 8:00 PM |
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| 10-4 Chris, I didn't forget. Hey, give me a call let me know if you found out anything. |
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hottubbrad
Registered Users
Posts:5
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| 06/06/2008 9:41 AM |
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I can't do the scribing method as we are in a supposed seismic zone. Near Ottawa. The wall must be put on a footing and not pinned to the bedrock. This allows movement if a seismic event occurs. Stupid, but thats life.
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Paul Stevens
Registered Users
Posts:143
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| 06/06/2008 2:07 PM |
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pick up some rolls of Tyvec house wrap, (cheaper than fast foot) use 2x4's for your footing boards, get it nice and level then attach your Tyvec, to the 2x's, make sure the Tyvec drops down either side and runs across the bedrock. You can check out pics on one of the sites for got to www.fab-form.com. that should give you a good idea. It is not a perfect way but should save you some concrete, also saves lots of plywood.
FYI, I was in California and saw a job where a 5000 square foot house was all scribed to the rock and using tyvec, engineer and building dept. approved it, and they definitely have a seismic problem, so it asks the question, who's right? |
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vermaraj
Registered Users
Posts:34
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| 06/06/2008 3:06 PM |
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| Tyvec is functionally equivalent to fast-foot? Specifically over bedrock or for general use? |
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Alton
Registered Users
Posts:314
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| 06/06/2008 4:16 PM |
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Vermaraj,
Tyvec house wrap should work well over rock since dampness should not be a problem. Fast Foot is used primarily for foundations, especially where rising dampness from the footer to the wall could be a problem. Fast Foot would probably be too water & vapor resistant to use as a house wrap. |
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Alton C. Keown
Residential Designer and Construction Technology Consultant
Auburn, Alabama
334 329-0957 AT&T Cellular |
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hottubbrad
Registered Users
Posts:5
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| 06/07/2008 8:30 AM |
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| OK so how do I stabilize 2x4's that are sitting 18"in the air above the bedrock?
I see the stakes in the dirt....but what do you do in the ROCK?? |
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Chris Johnson
Registered Users
Posts:341
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| 06/07/2008 12:29 PM |
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| As difficult as this sounds, drill 3/4" holes in the rock, use 3/4" stake dowels...it is a lot of work but it works |
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Chris Johnson - Pro ICF
Napa, CA
Come for the wine, Stay for the ICF work |
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hottubbrad
Registered Users
Posts:5
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| 06/08/2008 6:29 PM |
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| What do you think the most cost-effective steel would be for the stakes? I need about 90 stakes at 12-20", depending on where they go. I remember seeing 24" steel stakes over the years, that are pointed and have a slight head on them for a sledgehammer.... I just don't know where you would source them out...maybe surveyors.....
any help on this would be appreciated...
Also, which method would you use to fasten the form to the stakes? Steel roll strapping?? or what? |
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Chris Johnson
Registered Users
Posts:341
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| 06/08/2008 8:57 PM |
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Footing stakes are available in 18, 24, 30, 36, 42 and 48" lengths...I normally buy 36" that cost $ 2.45 each. I figure on a rock job like yours 20-25 will be damaged beyond repair when finished.
They come with holes in them, set them in the ground/rock, I use a 2 1/2" screw through the available holes to secure the 2x with.
Source them out at a supply house...even HD sells them in my area...overpriced mind you but, when in a clinch I'll get a few there
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Chris Johnson - Pro ICF
Napa, CA
Come for the wine, Stay for the ICF work |
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aronmac
Registered Users
Posts:39
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| 06/08/2008 10:06 PM |
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| Hey Chris, I was on a job where we had to drill a 3/4" hole for every stake. We greased every stake and put a plastic sock over them so that we could pull them out after the pour. Then after the pour, we put a screet pin on the stake (one which you can tighten to the stake with a screw) and pryed them up with a breaker bar, or vice grips. |
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Chris Johnson
Registered Users
Posts:341
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| 06/08/2008 11:16 PM |
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| Yes, we do that as well...now ask your laborer to remove them and see how many he bends the S41T out of and they become garbage...just venting a little...you get what you pay for |
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Chris Johnson - Pro ICF
Napa, CA
Come for the wine, Stay for the ICF work |
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robinnc
Registered Users
Posts:115
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| 06/08/2008 11:44 PM |
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Let me ask a probably dumb question. When they build bridges.......they go 'down' to bedrock to anchor it 'to' the bedrock. What's the story here??
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Paul Stevens
Registered Users
Posts:143
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| 06/09/2008 6:45 PM |
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| There are no dumb questions only dumb answers, and unfortunately I don't have one, anyone got a dumb answer, Chris??? |
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Chris Johnson
Registered Users
Posts:341
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| 06/09/2008 8:51 PM |
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Well...here is my dumb answer...
A bridge requires a pre determined depth into bedrock to provide not only shear stability but also to 'lock' the sides of the piers to help prevent it from moving/shifting under stresses caused by several factors including...but not limited to vehicular traffic (Live Load) Wind loads (TBD), sheer weight of the structure itself (Dead Load).
Without properly anchoring the structure to the ground the dead load by itself could very well allow the structure to collapse as the piers would be able to slide out and skid on the surface. Now if that didn't happen but you add a live load which would be causing harmonic vibrations the undue stresses could very well make everything shift and slide...hence, dig into bedrock and lock it in.
The above noted response is just a theory and not an actual mathematically calculated answer "DO NOT USE FOR CONSTRUCTION"
Someone want to tell me if I was even remotely close in my assumption?
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Chris Johnson - Pro ICF
Napa, CA
Come for the wine, Stay for the ICF work |
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Paul Stevens
Registered Users
Posts:143
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| 06/09/2008 9:03 PM |
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| WOW, now that's some answer, I felt dumb just reading it!! |
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woulfcc
Registered Users
Posts:185
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| 06/09/2008 10:58 PM |
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Just my $.02 worth here , I have used 5/8 or 3/4 re-bar asstakes drilled to the same size and dry fit into the rock.
I use elc. conduit bracket's to get the hight on a 2X6 to grade hight and screw it on elevation( use 2 per stake).
I would like to try the tyvec or fast footer but landscaping fabric is cheep and and works well for me.
All I save is the 2x6 and key way holding the vet. leave the the rest. (I f@#*N hate pulling stakes out)
One thing more is weep holes are about 4 ' apart using 3" drain tile so water can drain in or out and not build up.
This works well for me (your results may very).
I am sure Thar are a lot more tricks out their than this keep what you need and let go of the rest.
I hope this helps.
Regards,
Scott |
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Changing how the world BUILDS!
One build at a time.
Woulf c.c. |
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