payner
sage
Reged: 03/22/07
Posts: 212
Loc: Bluegrass Region, Kentucky
|
|
Quote:
Just had a thought.. How deep is your "Frost line"?
18" deep monolith with 4 "pylons" may sound good, but the main square is only 18"... If the ground heaves under that, the Pylons will do nothing for it.. They may even crack off. You'd almost be better off with a SINGLE hole of perhaps 18" in the CENTER would probably be a better deal...
Hello WidowMaker: The frost line in Kentucky is 7 inches, except in the mountains where it is 8 inches.
Your project is looking good.
Randy
--------------------
CGE1400 w/XLT & FT MicroFocuser
Russian-Intes MK 91 Rumak
Takahashi FS-128
|
Digital Don
scholastic sledgehammer
Reged: 01/20/04
Posts: 803
Loc: Manteno
|
|
Manteno is indeed in Illinois at about latitude 41° - south of Chicago and north of Kankakee.
I think the 'official' frost line in this area is 42", but I've seen depth ranges between 40-50" quoted. My neighbor had a fence installed earlier this year and code required the post holes to have a minimum depth of 42".
The construction people I spoke with recommended 48" depth for the footing.
Don
|
Manny Myles
Carpal Tunnel
Reged: 11/29/05
Posts: 1951
Loc: Flatlandia
|
|
WM
Stay away from pointy footings or any footing that tapers to a small area. The weight and time will want to sink it into the ground or want to squeeze it out like zit.
I would still dig it deeper and use the auger to loosen the soil up prior to removing it.
What you show is a lot of concrete above grade with no side support and it would be begging gravity to do its thing.
m2
--------------------
Light travels faster than sound. This is why some people appear bright until you hear them speak
|
WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 656
Loc: Frankfort, Ky
|
|
Thanks alot everyone for the help and ideas.
Quote:
Are you going to nail your floor joists between your outer 2x8 framing? And you will add joist hangers as well I take it?
All the 2x8's that go under the floor ( called floor joists?) will be in these little brackets things that attach to the 2x8 frame and to the 2x8 floor boards. Is that what youre calling a joist hanger?
Here's exactly what I got.
Quote:
The frost line in Kentucky is 7 inches, except in the mountains where it is 8 inches
Randy, where did you get that info from? Is this what youve learned, or did a builder or someone like that tell ya?
I cant seem to find anything that says that anywhere.
I just assumed that 24" was the safe spot.
Think it could be different in Frankfort?
Quote:
Stay away from pointy footings or any footing that tapers to a small area. The weight and time will want to sink it into the ground or want to squeeze it out like zit.
Um.
I dont guess I can sound any dumber, so what exactly is a 'footer'? Would that be my post? Or the hole i dug out for my box?
Quote:
I would still dig it deeper and use the auger to loosen the soil up prior to removing it.
What you show is a lot of concrete above grade with no side support and it would be begging gravity to do its thing.
Thanks, Manny. Just to be safe Im gonna try to brave the rain and thunder and dig my hole a little deeper.
It makes sense now that ive had some rest to have it deeper in the hole since so much will be standing up above the ground.
--------------------
Sleep is the Cousin of Death
|
Manny Myles
Carpal Tunnel
Reged: 11/29/05
Posts: 1951
Loc: Flatlandia
|
|
Some people call the footer or footing the concrete you are going to be mixing up soon and resting your scope on after it sets up.
I do believe though that what ever you call it is a seperate piece of concrete from you'd wind up with.
When I did foundation work we always poured the footing first then came back and set the wall forms OR whatever was going be rest on the footing.
A footing is a wider resting area for the rest of the concrete to set on by providing a larger foot print, typically 2 or 3 times as wide as whats being set on it.
To me what you are building is a pier, a simple monolithic pour and a footer/footing would be concrete poured in a hole,,, for your 4x4 posts to rest on.
My largest footing I ever helped with was a 125 yard cube and then a 25 yard foundation set inside that for a small drop forge.
In my 30+ years of concrete construction, I never heard of it being called a footer till I started reading posts here.
I helped dig my first footing when I was 10 (42 years ago)and that was for my dad's concrete business and mom wanting me out of the house. Call me Gopher.
m2
--------------------
Light travels faster than sound. This is why some people appear bright until you hear them speak
|
payner
sage
Reged: 03/22/07
Posts: 212
Loc: Bluegrass Region, Kentucky
|
|
Quote:
The frost line in Kentucky is 7 inches, except in the mountains where it is 8 inches.
Randy, where did you get that info from? Is this what youve
What you show is a lot of concrete above grade with no side support and it would be begging gravity to do its thing.
No, this would apply to Frankfort, it's not in the great white north climatologically speaking. At latitudes below about 39th• parallel (Cincinnati) the frost line is ephemeral most of the "cold season" except for January and most of February when days are more or less consistently in the 40s and nights in the 20s.
I got these data from US Dept. of Commerce, National Weather Service and will attempt to attach a map of the contiguous US showing these data. You can see when one gets to central Ohio and Indiana the frost line has increased 3-fold to >20".
Randy
PS- I am correcting myself in that the mountainous region has a 14" frost line, not 8", which makes sense to me--my vision was blurry at midnight last night after a days work and drive back home for 2 hrs afterwards RP
--------------------
CGE1400 w/XLT & FT MicroFocuser
Russian-Intes MK 91 Rumak
Takahashi FS-128
Edited by payner (05/11/08 11:51 AM)
|
WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 656
Loc: Frankfort, Ky
|
|
Thanks alot, yall.
nice attachment, Payner. How can i argue with that?
I think my problem will be a massive structure sticking out of the ground alot further than its in the ground. That whole gravity thing eludes me. 
I tried digging more in the rain and horrible wind but its no use. Its all massive mud and I dont think im doing any good. I dont seem to be getting anywhere.
I guess ill give up for now and take my wife for a nice lunch somewhere, that whole Mothers Day thing.
Youd think allowing her to dig in the mud with me would be reward enough, but nope. Some women require pretty things, and warm food. Go figure.
*sigh...
--------------------
Sleep is the Cousin of Death
|
cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
|
|
You have the perfect joist hangers.
I'm with Manny here, never heard of a footer before, and keep the bottom of the hole flat. Manny's explanation is dead on.
And with an 8" frost line, it would appear that you will be fine.
Talk to you later.
Keith
|
NeoDinian
Experienced Postmaster
Reged: 10/05/05
Posts: 11511
Loc: Rockford Illinois
|
|
As for the manteno 48" line, chances are that is NOT the actual frost line, but rather the city CODE for depth below the frost line.. Up here (Further north than Manteno) in Loves park, our "Frost line" is 38 inches, but CODE tells me to dig a minimum of 6 inches PAST that.. So 44 inches is our Code depth for the frost line.
--------------------
Neo... (Jeff)
-=-=-=-=-=-=-
10" LX200-GPS/SMT UHTC "Draco"
 Rockford, Il.
NeoDinian's Eye on the Sky!
Coming soon:
|
cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
|
|
Jeff, that makes far more sense, doesn't it? It looks like WM should be deep enough. The other consideration is that the obs will far more than cover where the pier is, and the ground likely will not freeze that deep anyway when it is partly covered.
Keith
|
DeanS
sage
Reged: 07/12/05
Posts: 406
Loc: Nicholasville, Kentucky
|
|
Michael, I bet you didn't get much done today did you??
Dang heavy rain and strong winds all day.
--------------------
8" LX200gps
AP1200GTO Mach1GTO
FS-60C Tak E160 C9.25
SXV-H9 ST2000XM STV
Meade 12" Lightbridge
Moonlite Focusers
www.doghouseastronomy.com
|
Digital Don
scholastic sledgehammer
Reged: 01/20/04
Posts: 803
Loc: Manteno
|
|
To comply with the forum's rules, I've removed the image.
Please use this link and my next post to see the map: Frost Depth Map
The map shows a range of <.5 to >1.25 meters for Illinois. So, in my case they actually went down further than necessary.
I guess the 'experts' who told me 48" were incorrect. But, better too much concrete than not enough!
Don
|
NeoDinian
Experienced Postmaster
Reged: 10/05/05
Posts: 11511
Loc: Rockford Illinois
|
|
Can you provide a link so we can see the full res image?
--------------------
Neo... (Jeff)
-=-=-=-=-=-=-
10" LX200-GPS/SMT UHTC "Draco"
Rockford, Il.
NeoDinian's Eye on the Sky!
Coming soon:
|
Digital Don
scholastic sledgehammer
Reged: 01/20/04
Posts: 803
Loc: Manteno
|
|
Here's a direct link to the map: Frost Depth Map
And here's a link to the beginning of the publication: NOAA Manual
It deals with the installation of Geodetic Bench Marks.
Don
|
RobVG
professor emeritus
Reged: 01/09/06
Posts: 554
Loc: Seattle Washington
|
|
The planning department for your county should be able to tell you all local codes- including footing depth.
Ours is 18"- to the bottom of the footing.
--------------------
C11 SGT(XLT)CG-5
Observatory (page 5)
|
WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 656
Loc: Frankfort, Ky
|
|
Hey Yall.
Naw, Dean. I got nothing but muddy this morning. It rained and thundered, then got pretty and sunny. I ran out with my shovel and started digging in the mud and then got poured on 10 minutes later. Its pretty much rained all day.
I wish I could have come over lastnight to see your obs, but after working hard all day I was asleep by 9:30...only to wake up consumed with thoughts of digging at around 7ish this morning.
Don, thank you for the map.
Um.
Since i dont have enough brains to kick my way out of a wet paper bag, can you tell me what it means?  
It seems to indicate that im '.50' but what does that translate to a corn pole like me in a hole with a shovel?
Was paynor correct that I need only go down 7", or is NOAA saying different?
Im also kinda stuck on another question.
Now that I *could be done with my 30x30" dob square, what size hole should I dig for a pier?
Is there like a 14x14" or 12x12, or even 16x16" hole I should dig that would cover me for whatever comes?
I have no idea what size scope Ill get for doing astrophotography some day. Smart, eh?
All I know is that I will probaly give it a try sometime, like perhaps as a Christmas present.
Is there a sized hole I could dig that would cover me?
Say for instance, I build a 16x16" square of concrete up to the floor like my dob square. Would that pretty much cover me down the road?
I can say for certain I will not be buying a $25,000 scope to sit on it, more like a deal I found used somewhere.
Also, I may be ready to start my pour into the dob hole tommorrow, If I can get out there. Some have said I can use the 'quik-rete I have left over from the fence posts, others say use 'Portland cement'.
The quik-rete will not allow me to make a pretty smooth base to sit my dob or pier on, right? It will be chunky with rocks in it.
Cement only? It needs to be flat and smooth like my driveway, right? I was gonna dump the three or four bags of quik-rete i had left over into my dob hole, then fill the rest up with cement. See any problems with that?
--------------------
Sleep is the Cousin of Death
|
Digital Don
scholastic sledgehammer
Reged: 01/20/04
Posts: 803
Loc: Manteno
|
|
"It seems to indicate that im '.50'... "
The map is showing depth in meters - .50 meter is a little under 20". Do that and you should be good to go!
Good luck!
Don
|
DeanS
sage
Reged: 07/12/05
Posts: 406
Loc: Nicholasville, Kentucky
|
|
Quick crete will make a smooth finish on top if you work it with a trowl while it is still wet, that is pretty much how they do sidewalks and driveways anyways.
Make your base as big as you can stand to. I would not want to go much more than 2x as high as it is wide. So if it is 4' in overall height, I'd make it 2'x 2' if you can. And as for depth, I would min 2' deep, and again half at least half the overall height in the ground.
That is how I would do it to satisfy my own concerns. Maybe it is overkill but I like to do things one time.
--------------------
8" LX200gps
AP1200GTO Mach1GTO
FS-60C Tak E160 C9.25
SXV-H9 ST2000XM STV
Meade 12" Lightbridge
Moonlite Focusers
www.doghouseastronomy.com
|
astrotrf
sage
Reged: 09/30/07
Posts: 215
Loc: Rodeo, NM
|
|
Quote:
I too am surprised that the frost line is 48". But who knows, could be.
Growing up on a farm in central Wisconsin, I recall that the frost depth in our area was about 6 feet. We had to replace the water line from our well to the house, and it had to be buried at 8 feet! I wouldn't want to hand-dig for a telescope pier there ...
--------------------
Terry (astrotrf)
|
John Fitzgerald
In Focus
Reged: 01/04/04
Posts: 1028
Loc: AR
|
|
Don't use PURE Portland cement for anything. If you thoroughly mix in about a shovelful of Portland cement per 80 lb bag of the Quickcrete it will make the Quickcrete much stronger. Anyway, the Quickcrete itself needs to be well mixed. If you pour it into the hole without mixing, it will just make a mess. You will need to put a few sticks of 1/2 inch re-bar in the Dob base (pier) also.
--------------------
?
Observing since 1966
Messier Cert #898
|
Previous
Index
Next
Threaded
[Re: 
Edit
Reply
Quote
