I’m planning to build a garage, finally. The frostline is 42 in., and the site is pretty flat. I figure a 16 in. wide x 10 in. thick footing with an 8 in. x 48 in. stemwall will do the trick for the foundation. Here’s my dilemma. First, I don’t want to hire it out because I like doing the work, and there are only about 6 people on the planet I trust to work on my jobs. And none of them are concrete guys.
So, I’m thinking that I either use 3/4 in. Advantech and make my forms, reusing the Advantech for the second floor deck because my grandparents were Scottish and it’s genetically difficult for me to spend money, or I use ICFs. I’ve done a couple of ICF foundations, and know that would save a ton of time. But it’s that money thing again. But the Advantech forms would take a bunch of time I don’t have, and waste quite a bit of bracing lumber.
Anybody got a better idea?
Andy
“Never try to teach a pig to sing. It wastes your time and annoys the pig.” Robert A. Heinlein (or maybe Mark Twain)
“Get off your dead
and on your dying feet.” Mom
“Everything not forbidden is compulsory.” T.H. White, The Once and Future King
Replies
I'd do the ICFs in a heartbeat. Re-using the old form sheets for flooring is always a dusty mess.
If you place carefully, you can skip bracing - I have, with a 4' high 20x32 addition. We used a line pump though, so it wasn't a huge amount of flow volume.
Forrest
dig the footer the width you need to a depth you need, that be 16 inch wide by 58 inches. drive some scrap rebar the elevation of the footer top. drop your rebar in the hole and then pour your concrete, vibration till th etop of the rebar poke his head out.
You might want to look into a frost protected shallow footing. A quick Google yielded this web page.
Personally, for a regular stem wall situation I would dig and pour your footings, and then come up out of the ground with 8" block. Then fill the foundation interior with stone and place slab. That would be the cheapest way. Here masons get ~$1.50 a block and the 8" block themselves might be about the same price. Labor is probably more where you live though...
BTW - we wouldn't even bother forming the footings. Depends on your soil type though. Footings for that application should be 8" thick x 20" wide.
Personally, I think using ICFs for that application would be a waste.
I'd love to do frost protected shallow footings, but the IRC only allows them for heated buildings. I don't intend to heat this all the time.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
Thanks for the replies. Lots of regional differences. To them: Brownbag: If I could dig a straight sided trench footing, I would also skip the forms. But that doesn't happen in my part of New England. You know those stone walls we're famous for? For example, I own 13 acres, and there's over half a mile of stone walls on them. I'll get enough stone from this little excavation to build the damn garage. No way will that result in a straight sided trench.Dino: You're building to a different code. Eight inches is fine here. Whoever posted about ICFs: Yeah, but the money. My poor Scottish grandparents spinning in their graves and no way to use the motive power...Mike: What spacing were you using on the whalers?Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
andy.... it's been a long time .. but :
i'd predrill my 1/2 x 4 x 8 panels for the snap ties
the sheets wil be horizontal for your 4' wall.... from the left..
a vertical row of holes @ 12" ....36"...... 60"..... 84"
@ 2" from the bottom.... 16" ....32"..... 46"
then your horizontal 2x4 whalers will wind up 16" oc..
and your vertical 2x4 whaler clamps could probably be 4' oc
or 2'oc if you want
you can rent the form dogs where you buy the snap ties
or you can take a ride and borrow my dogs
tack everything in place... insert your snap ties on the inside
and stand up your outside.. insert the snap ties..
the horizontal whalers lie on the ties loose ... occasional tacks
with an 8d duplex nail... lap your joints with the whalers
lap your corners too... 16d duplex nails will hold it all together
then stand up your 2x4 whaler clamps and loosley put your dogs on to clamp them
tighten everything up
use brute force to get things into alignment ( or a good pry bar )
shoot your grade.. snap your grade lines....... use 6d bright nails for grade.
or.... have Cadioli come visit for aweek.... let him earn his keep
see you at JLC I hope
pour and thump.. don't vibrate unless you know what you're doing
Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Thanks, Mike. I talked to Rick Arnold about this, and he's got me thinking about trying to get my local AHJ to approve a rubble trench foundation. I like that idea a lot, and it's held up Taliesin for a century or so.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
i like rubble trench...
on the interior, about a foot of bankrun or processed gravel
then a monolithic thickened edge slab on the rubble trench footing
Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Exactly. But where is that in the IRC? I don't see it. It used to be detailed in the CABO book.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
i don't know where it is ... or if it is, in the IRC
but it might be worth while having an engineer stamp the alternative foundation. Talk it over with your BI and see what they think .
Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
I'll do that. God knows he's not busy right now. I also emailed my engineer about it. I'd love to do a rubble trench. That's my idea of a practical footing. Fast, cheap, and out of control. Wait, that's a movie. Fast, cheap, and effective. That's a motto.See you in Providence. One of these years I'll be able to join you for lunch, but not this one. How about a beer after?Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
andy,up here in ct. where are frost is 48'' out here some are done trench,block and rebar. they will hold up and last longer than us. this method works well.and not as pricey as other ways.although the other ways are very good.good luck. and remember alittle overkill won't hurt,it just makes it a little stronger. also watch out for surrounding sloped areas. when your done have a shot of that good old scottish whiskey.your gps' im sure would approve,at that point.
Where in CT are you? You must be further north than me. Our frost depth is only 42 in.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
I don't think rubble trench is in the IRC, but if you can get an engineer to stamp it you're good to go. Not a reason in the world why it shouldn't get stamped.I'm all for rubble trench. Works great. Good thing of it, or half the stuff around here would have fallen down 200 years ago.One improvement; after you dig the trench, line it with geotextile, and then put the rock in. It's a much stronger and more durable job that way. Keeps the rock where it is supposed to be and likewise for the dirt.I'd also check into topping the rubble with CLSM aka lean fill. A lot cheaper than concrete and easier to work with. I don't know if the engineer will go for that, but in your seismic zone I see no reason why not.
You've talked about lean fill, but I've only ever heard of it being used on highway jobs around here. Doubt the local AHJ is familiar. And I don't want to throw him too many curves. I'm planning to heat the place with a water heater, so let's not push our luck.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
<<. . . so let's not push our luck.>>While I appreciate the inherent wisdom of that, I have also come to realize that as The Boss,-- pushing my luck-- flying off the handle-- riding people's ^sses, and-- jumping to conclusionsis the only exercise I get anymore.
That and spinning your dog around..Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
<G>
Andy--
Footings should be 24" wide 'cause frost walls at that depth are 12" thick. You can use old scaffolding planks or 2x10s for the footing forms, but rent some real forms for the frost wall. Yeah you could make your own forms outta whatever, but it'll take you forever and when you get done you're gonna have a bunch of concrete-encrusted wood with lotsa holes in it from the wire ties. Not worth it....
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Didn't you do a nice article on ICF's a couple of years ago? You could do another with your shop as the subject. Sell the article to FHB or JLC and now the whole works is one nice big tax deduction.
Have a good day
Cliffy
Edited 3/1/2009 8:32 pm ET by cliffy
Form it like everyone here does for all foundations. Make your footings out of 2x8s with 1"x3"s every 3 ft top and bottom to tie them together. Use 1"x8" for the foundation walls nailed to 2"x4" uprights at 3 ft on centre. Level the forms with a 2'x4" whaler on the outside and pour the whole thing at once. Even a slow guy like me would be able to form it up in a weekend.
Once you are done, you can strip the forms and use them as sheathing on the garage. Next to no waste, no rentals and easily adapts to uneven excavations.
its werid how different parts of the country do thing. I see a lot of form footers here on this site, but out of 25 years in the business here, I have seen less than three, formed and maybe 10,000 un formed. alot of time , material and effort for something that will never be seen once done.
No real rhyme or reason to it - just regional peculiarities I guess.
we form our footings because they support the rest of the wall's formwork, as we pour everything in one go.
i'd use 1/2 ply and reuse it for the wall sheathing
also... with a 48 " form .. assume a 44 - 45" wall.... not a 48
so... 42 " frost depth .. less 10" footing... you need 32" to grade + 8" to bottom of sheathing... it all works
you can buy a box of snap ties for 8" wall and use 2x4 whalers ... we used to do it all the tme... but the last time we did it was when cadioli was working with us on 9-11-
8" wall.....1/2' is plenty for formwork
If a monolithic "Alaskan: slab pour is out of the question I would do 8" block. You will need to over-dig though to have room to work. 2-3 guys should be able to knock out the block work in a day handily.
You probably want to get some insulation up against the block and under the floor to keep your feet a bit warmer in the winter.
I used to own a garage building that had a concrete foundation poured in a narrow (maybe 12 inch) trench to grade then one or two course of block laid on top. Built in 1940's or so. Was still holding up fine into 2004.
You'd need a good excavator and the right type soil. Rocky or sandy won't work. I think I'd use 2x6 form around the top edge leveled and straightened.
Rich
Can you lay block? It's good exercise and something you can do yourself.
Sure, I've laid lots of block. But that was when I was younger and back pain was wasn't even hull-high on the horizon. Not doing that any more.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
I said that 20 years ago but I'm still doing it! It always seems to be the quickest & cheapest alternative for us.
We usually knock off a normal garage frostwall in one day and then head home and say " we're getting too old for this..that's the last one.....we're going to have to hire this out pretty soon"
Now that things are slower, there will be all kinds of union block layers looking for work.
ICF's are just too expensive to be using them for frostwalls and by the time you are done messing with making your own forms, you could have hired someone and be working on the walls.
I might have just gotten some leftover ICFs for this, which pleases me. Otherwise, I priced them out last night. It would have been crazy expensive.I'm pretty much set on doing a frost protected shallow footing now. The extra foam insulation will only cost about $500, and it'll save at least twice that much in concrete. Plus, I'll only need to dig out about a foot and a half. I'm not getting in any trench and laying block, no way, no how.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
I'm not getting in any trench and laying block, no way, no how.
C'mon Andy. It should be no problem for a young guy like you. I did this one two years ago, when I was 57:
http://www.jlconline.com/cgi-bin/jlconline.storefront/49b050f9095d38fc27170a32100a0617/UserTemplate/82?s=49b050f9095d38fc27170a32100a0617&c=caf5cd1293bc0af98a01763ad2c2e814&p=1
If you're willing to play in the mud, it's the cheapest route. One of the things that I like about block is that you can run the block up to floor level, then use the block as a form for the concrete floor. Then you can continue up with the stem wall to get the frame up off the ground. For aesthetics, I continued up in brick on this job.
John, that is fine, laying blocks, when you only have to lay 2 courses to get to ground level. I think he has to be down 4"!!!!
That means he can have twice as much fun! ;)
I would lay the blocks or do as he said. I find that laying blocks isn't that bad>G<
John, while you're ten years older than me, you've lived a clean and virtuous life. And Frammer is right - I have to go down 4 feet. Plus, my back has been giving me trouble since I was 29 (Right about when my oldest kid was born - Is there a causal relationship going on there, I wonder?) Given these concerns, I'm willing to trade a little money for the time and pain savings. And it's a very little bit of money as I would insulate below the slab anyway. The FPSF is only going to cost an extra $600 in foam beyond what I would have bought. I doubt I could buy the block and concrete for the footings for that money. Even valuing my time at $0 per hour, I think this is actually going to save some cash.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
what's the foam spec you'll be using ?we typically would go to Branch River and buy 2 lb/cf Performguard .... probably 2"Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
The ASCE design spec calls for a minimum 2 pcf foam, and what I'm finding locally is all 2.5 pcf. It's amazing - the bearing capacity of that foam exceeds that of the soil. I can use a 12 in. perimeter footing, and the two end point loads only need 24 in. footers. The only oversize footing I'm doing is for a center column that has a larger tributary area. And that only needs to be 32 in. square.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
Andy,
The foundation in the article was in North Carolina. The bottom of the footing there was 18-in down, which made the block work pretty easy. I've also done quite a few block foundations in Maryland (and one in Delaware) where the footing went down 32-in. The extra two courses weren't too bad but they did add to the price of the job. Where you live another course would be required. Four courses below ground! I have to admit that that would start to get old.
My own preference for block is influenced by the fact that I own a mixer, mortar pans, wheelbarrows and all the hand tools. I've done quite a bit of masonry work in my life and still enjoy it (something I can't say about a lot of the work I do). I've been lucky with my back.
In the 1980s I lived for 3 years in Hampton, NH. From experience, I have to say that you pay a premium for the privilege of freezing your butt off for four months each year. Everything about building a house in New Hampshire--starting with the mean, rocky soil and ending with the ice dam-prone roof--was more difficult and more expensive than building in North Carolina or Maryland.
When in New Hamshire I knew a couple of people who built shallow, freeze protected foundations for shops. They seemed like a great idea but I never tried it myself.
I won't be able to make JLC this year. Hopefully, I'll make it next year. --John
John, What you have to explain to the young man, is that it's the first few rows that are the killer. We always use six block high frostwalls. The last three rows are a breeze...nice and comfortable!
>> The bottom of the footing there was 18-in down, which made the block work pretty easy. <<
What'd you go so deep for? :-)
Andy, search the FH archives. There is a great article from a few years back I was just re-reading about frost-protected shallow foundations, written by a PA builder, and he shows all the details necessary for doing an unheated garage package with curbs.
I would cite issue # and date, but am on the road tonight.
OOOOOOPPPPPSSSSS! just read your part about IRC not allowing FPSF for unheated. You sure about that? We do it in upstate NY regularly.
If for certain you cannot, it may be a great excuse to use ICFs and the integral footing done using FabForm Industry's fabric. A little staking, some rollformed steel hat sections, the roll of fabric, the same zip-ties used on jihadi POWs, and your ICF blocks. One nice integral pour, and you are ready for your slab prep work.
The FabForm stuff is sort of a western Canada thing, but what the heck, maybe crusty old New England is ready for something new. If TOH jobs can be done using precast Superior Walls foundations, you Yankees should be using fabric.
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"A stripe is just as real as a dadgummed flower."
Gene Davis 1920-1985
Edited 3/6/2009 10:06 pm ET by Gene_Davis
The IRC has details for unheated parts of buildings attached to heated buildings, but it doesn't cover freestanding unheated buildings. The ASCE Standard 32-01 that the IRC references for the FPSF that it does cover also includes details for unheated buildings. Not much different - the insulation needs to go further out from the building is all. I'm pretty sure I can get the AHJ to sign off based on the design from that document, but if not, I can get it stamped by an engineer.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King
If the building is unheated, why wouldn't you just allow it to float with the frost.
In SE MI (clay) , they required 42 footings for house but allowed a 24" ratwall for unnattached garages. The rats woudn't tunnel more than 24" to get under the wall in the winter.
Some localities allowed the garages to be poured on 5" slabs with no footings. The garage just rose and fell with the frost.
They also allowed attached garage to be poured on 8" x 42 poured "footings" although most were 12" x 42. The wider footings provided both a lip to catch the garage slab and also a brick ledge.
It's a garage. It don't matter if it heaves...it'll go back down where it belongs in the spring.
I think the concern is differential heave. If the soils are consistent, and if they're consistently drained, and if the shade of the building doesn't cause one side to move at a different rate than the others, you might be okay. But if the movement isn't consistent, you end up with stresses that can crack un-reinforced masonry.The other issue is the same one that causes rocks to pop out of the soil in the spring. As the object is raised up, particularly by frost adhesion to the foundation, voids are created where bits of dirt can fall fall under it. In time, the rock or the building gets pushed up out of the dirt.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein (or maybe Mark Twain)
"Get off your dead #### and on your dying feet." Mom
"Everything not forbidden is compulsory." T.H. White, The Once and Future King