Building a Garage

[KiwiBro (deleted)]

Have to be below it

Well that kinda blows the ribraft out of the (frozen) water. So, trench footings down as low as the standards suggest or does anyone point the slab load onto piles drilled to depths below the frost line? I'm thinking less concrete in the latter but have never really given it much thought. How to insulate the slab from the ground temps though? Polystyrene? Are heated concrete slabs common in frost prone areas?

 

[EvilRoySlade]

A very serious question is what comfort level inside do you want. Do you need to manage moisture levels, lots of iron equipment. Point being insulation makes huge differences in northern states, including sub-slab, thermal breaks between slab and footer etc. Remember, your soil temp will hit 60ish under your slab and much lower in mid winter. You’ll be condensing on it in summer and heating earth all winter if you don’t separate with insulation. Moot point if it’s just a regular pole barn with random usage.

 

[huskihl]

Well that kinda blows the ribraft out of the (frozen) water. So, trench footings down as low as the standards suggest or does anyone point the slab load onto piles drilled to depths below the frost line? I'm thinking less concrete in the latter but have never really given it much thought. How to insulate the slab from the ground temps though? Polystyrene? Are heated concrete slabs common in frost prone areas?

If its going to be lived in, it has to have frost protection all the way around the perimeter. Foam insulation is used if it's gonna have hot water tubes in the floor. Sometimes it's used without heat in the floor.
In a pole barn, the posts need to be below frost, but not the entire floor

 

[Johnmn]

So I'm in a 60" zone but a floating slab will pass code. The actually work really well, you just need proper dirt work, bell footings around the perimeter and 2" foam around the perimeter. My first house was built this way but I also had foam under the slab and hot water heat in the slab.
I'd say over 75% of the buildings we build are on floating slabs.

 

[KiwiBro (deleted)]

So I'm in a 60" zone but a floating slab will pass code. The actually work really well, you just need proper dirt work, bell footings around the perimeter and 2" foam around the perimeter. My first house was built this way but I also had foam under the slab and hot water heat in the slab.
I'd say over 75% of the buildings we build are on floating slabs.

How deep are the bell footings? 60"+?
In very unstable soil sometimes we'll still drill piles down to stable/solid ground even with a rafted/floating slab. Sometimes easier, cheaper than excavation and/or retaining.

 

[Marshy]

I was just saying I thought I saw you on a logger wade video before.
Here's the video I was thinking of, at 6 min or so you can see their new barn, maybe there's something better about it in another one, don't watch them all.
Post a link to that video, I'm still waiting for mine yet, one day...

Oh, right on man. I haven't watched his pole barn videos yet, been slacking. But yeah, that's the idea. My soil is sandy loam and I know I have a high water table so deep footing wil be needed.

 

[chipper1]

My soul is sandy

Probably should have that looked at by a professional .

 

[chipper1]

Good point. Zero frost heave in the top third of NZ. Do you guys always have to get below the frost line, or can you just stop significant moisture getting under the slab/footings?

As Kevin said the goal is to get below it.
You will have frost deeper when the soil is wet, so sandy soil will have a lower water content than clay.
It seems that stopping the water from getting under them would do the trick, but I haven't heard of that in a code here. If it's too wet you will have to have a substantial drain system set up before building in that location.
There were many counties where you could have a floating slab and build directly on top of that, but I don't know if there are any here that allow that now.

 

[Johnmn]

How deep are the bell footings? 60"+?
In very unstable soil sometimes we'll still drill piles down to stable/solid ground even with a rafted/floating slab. Sometimes easier, cheaper than excavation and/or retaining.

Bell footings are usually 18" wide x 12" deep on a floating slab. Around here they only make you drill piles down if the soil is really bad!

 

[Viper21]

So I'm in a 60" zone but a floating slab will pass code. The actually work really well, you just need proper dirt work, bell footings around the perimeter and 2" foam around the perimeter. My first house was built this way but I also had foam under the slab and hot water heat in the slab.
I'd say over 75% of the buildings we build are on floating slabs.

I had no idea there were areas requiring 5' deep footings. The deepest I've encountered (code-wise), is 30". I live in the semi-mountains of Virginia. Our footings must be 24" is all...lol. Granted the shale we are on is pretty solid to begin with. As anybody who's dug a hole by hand well knows. We get cold but, below zero doesn't happen that often.

 

[Stump Shot]

Some have started putting 2" foam board so it extends out of the slab and is buried underground to keep the frost from penetrating the ground next to the slab, thus no frost to work its way under. Not sure what the specifications of all this are though.

 

[chipper1]

Some have started putting 2" foam board so it extends out of the slab and is buried underground to keep the frost from penetrating the ground next to the slab, thus no frost to work its way under. Not sure what the specifications of all this are though.

Last I knew no foam on the outside of the wall, figure that would be the same for what your describing here, it's a great home for insects.

 

[Stump Shot]

Last I knew no foam on the outside of the wall, figure that would be the same for what your describing here, it's a great home for insects.

Not here in the frozen tundra. Lol
A lot of frost walls are poured with styrofoam forms and stay permanent. Most basements have a foam board on the outside as well.

 

[chipper1]

Not here in the frozen tundra. Lol
A lot of frost walls are poured with styrofoam forms and stay permanent. Most basements have a foam board on the outside as well.

Funny how much the rules change from one area to another. If I were to build a house I would use superior walls for the basement.
Now that I think about it, many use foam under floors especially with radiant heating in them, wonder why they allow that here, but not on the walls .

 

[huskihl]

Funny how much the rules change from one area to another. If I were to build a house I would use superior walls for the basement.
Now that I think about it, many use foam under floors especially with radiant heating in them, wonder why they allow that here, but not on the walls .

Every new basement is required to have installation of some sort on it now. I believe it has to be r-15 or 19, not sure which currently. But that equals up to 3 to 4" of foam or 4-5" fiberglass. On top of that, the only kind of board that's allowed to be exposed on an inside basement wall is thermax because it meets fire rating. So basically, you either use foam blocks and drywall over the inside, 8in CMU with foam outside the walls, 8in CMU with foam inside the walls and drywall over it, or you stud the wall out and insulate between the studs and put drywall over that. What a p i t a

 

[KiwiBro (deleted)]

It's also crazy how much the rules change, sometimes more than once per year. Must be a universal global rule that nothing stays constant in the building trades. I have no problem with real progress but some of the crap they ram down our throats is clearly the result of business lobbying. I have also been around long enough to see some of the things the old timers used being tweaked slightly to be proprietary and passed off as the new wonder system or product or solution to address a problem that was solved three generations ago but some would say deliberately brought back into the cycle to provide another revenue stream for various business interests.

 

[huskihl]

The latest rage....

New homes need to be "pressure checked".

They pressurize your home and see if it passes or fails.

But new homes are also too airtight, so you're required to run a 4" fresh air duct from the outside and into your return trunk on a forced air furnace.......

It's all politics. Gotta have people to create and revise codes. Gotta have more people to enforce them.

 

[Stump Shot]

New codes around here are like a bad infomercial. New rules go with new products to get pushed.

 

[KiwiBro (deleted)]

New codes around here are like a bad infomercial. New rules go with new products to get pushed.

This is when i would like to see builders forming a co-op. Each builder pays an annual fee that gets spent on putting test results behind totally non-proprietary methods and ubiquitous products so specifiers and the like can feel their backsides are covered if they specify or use these as alternatives to the products the big businesses are pushing on the standards makers. There used to be govt departments that did much of this testing but the whole user pays/privatise model has seen them off.

Building inspectors here are like magpies - attracted to all the shiny bits because some company has done the testing and the inspectors arses are covered if it fails. Crazy *s-word the way the world is heading. WTF should I use metal connectors from company XYZ when two very long screws will provide the requisite hold down for a truss? Why should i use metal connection straps/strip connectors for butted joists when i can just sister it with more wood and a prescribed type, number and spacing of gun nails, etc.

 

[Viper21]

Building inspectors here are like magpies - attracted to all the shiny bits because some company has done the testing and the inspectors arses are covered if it fails. Crazy *s-word the way the world is heading. WTF should I use metal connectors from company XYZ when two very long screws will provide the requisite hold down for a truss? Why should i use metal connection straps/strip connectors for butted joists when i can just sister it with more wood and a prescribed type, number and spacing of gun nails, etc.

I've met some knowledgeable BI's over the years but, they are far, & few between. Most I've encountered, don't know anything they haven't read in a book, & have little understanding of the difference between, book & practical application.

The best one's I've ever met were unsuccessful contractors. Nothing like having someone who couldn't make it in a trade, tell other tradesman how it should be done...lol

BTW.... Those hurricane straps on your trusses are a good thing imo. Screws don't have much shear strength, & I have seen some trusses move, that were simply nailed to the top plate, or screwed.

I do butt joints the way you described. I've done beams supporting roofs that way with, 3 or 4 nails (16d) vertically, every 12".