barn foundation advice needed!!

popeye151

Member
Livestock Farmer
hello, im new to this forum and this is my first post.....here goes.

Im going to be building a 60ftx30ft timber agricultural barn this year, and have a few questions related to the foundations. Im copying the design from a few barns ive seen, so carpentry wize, im sorted. Unlike most ive seen, i dont want to just dig a hole, put the post in it and back fill, as this will rot out and cause problems later down the line. Im going to get steel shoes made up so i can fix them to the bottom of the posts then bolt to the pad.

first question, how big a concrete footing should i have under the posts? 2ftwide x 3ft deep??

second q, Ive seen steel framed barns concreting in the threaded bar , using these waxed cones. I guess these give me more room for error as i can move them slightly? Where do i get them from? Anyone got any photos of the details? And an explanation of how to set them up? This is what im most confused about!

third, I was going to build up these footings up to finish level of the concrete pad, so the bolts of the shoes aren't burried in concrete. any reason not to do this? Ive read some people say the steel base plate needs to be under the finish concrete level. not sure why

fourth, ive read i need to use shims and washers under the steel plate. any idea why?

5th, what size bolts? m20?

6th, thickness of pad? i was gonna go for 6inch. we have a small(ish) 4wd tractor, and keep a few cows on it. nothing majorly heavy.

ok, i think thats all! thanks

any advice, big or small, most welcome. and photos too
 

Flatlander

Member
Arable Farmer
Location
Lorette Manitoba
Firstly go buy a laser level to accurately get your levels. If you intend to pour a foundation block don’t cheap out on size and use the laser to get them as close to perfect in height as possible. If bolting anything to the block leave it to cure long enough. As far as bolting the post to the concrete there are probably brackets available to do that already if you look. When pouring the floor slab the base is very important. Here we are faced with extreme cold but still important to get a hard base to pour onto. 6 inches should be ok with rebar an a foot square grid pattern. I’d go extra on the entrance ways if a tractor is going to be going over it just to be safe. 8 inches for a few feet should do it. As fir the shins it’s more than likely they are to level the posts up fir discrepancies in the footings. Built a shed here and we drilled 24 inch diameter holes where the post were going 4 ft deep. Cleaned the out well and packed the soil in the bottom. They were all drilled accurately. Then the concrete forms were put in the outside edge,rebar across the floor and into holes all in one piece. Concrete poured fir posts and floor all in one piece the built up from the slab using angle plates to secure posts.
 

Wisconsonian

Member
Trade
The shims and slotted plates are for steel buildings that need to be accurate to bolt together. If you do a decent job with layout, then it will be close enough for wood, and if you don't do a decent job, then shims and slots aren't going to be enough to help anyway.

Here, it's prefered to have the steel a couple inches above the floor level to keep it cleaner and dryer.

Br Jones might be thinking the same thing I am, you seem to be substituting steel frame parts into a wood frame design. They work differently, the wood poles in the ground provide structure to the frame that is not the same as the connection of a steel frame to the base. You can't just swap one part for the other without re engineering the building.
 

Kidds

Member
Horticulture
My shed base is 6" concrete with fibres and no mesh. I too only have a smallish tractor but I am confident any size tractor will go on it no problem, in fact I think 5" would still have been more than enough.
Each stanchion is bolted to 1m3 concrete and the bolts concreted over in the slab. As said above that is not what you do with wood.
 

popeye151

Member
Livestock Farmer
The shims and slotted plates are for steel buildings that need to be accurate to bolt together. If you do a decent job with layout, then it will be close enough for wood, and if you don't do a decent job, then shims and slots aren't going to be enough to help anyway.

Here, it's prefered to have the steel a couple inches above the floor level to keep it cleaner and dryer.

Br Jones might be thinking the same thing I am, you seem to be substituting steel frame parts into a wood frame design. They work differently, the wood poles in the ground provide structure to the frame that is not the same as the connection of a steel frame to the base. You can't just swap one part for the other without re engineering the building.

i agree i definitely need some substantial bracing - its amazing how little steel frames seem to use. but i dont see why using steel shoes bolted to the pad would be an issue. my posts are 5x14 (much bigger than any posts ive seen on other similar barns)
 

Farmer_Joe

Member
Livestock Farmer
Location
The North
you will be fine,

if your capable of building all the wooden part im sure you more than capable of putting a few bolt boxes down,

the idea of the 'foundation' as i understand is ballast to hold the building in place, there really not heavy say compared with a block and stone wall of a house which have much smaller sized foundations.

The std size is around 3ft square by 2/3ft deep, is it windy where you are or exposed? how bigger bays are you making, this is for 15ft bays, if your are less i would adjust accordingly.

depending on location i would be tempted not to use holding down bolts (the ones cast into the 'bolt box') just use std expanding bolts m20 just get plenty in each leg say 6.

there is no reason the bolt boxes can be finished floor level if you want them to be, just makes it neater if there below if you are concreting the shed.

pm me as stuff might be much easier to explain on the phone if you like.
 

JCB_JCR

Member
Livestock Farmer
Location
Somerset
We regulary drive telehandler/tractors on 3 inch thick and thinner concrete pads in sheds. Most with fibres in. Some of our cow feed passages are at most 2inches thick and haven't broken up. Just make sure what's underneath is firm.
 

Wisconsonian

Member
Trade
... i dont see why using steel shoes bolted to the pad would be an issue. my posts are 5x14 (much bigger than any posts ive seen on other similar barns)

For 60ftx30ft you'll probably be fine. I can't see why you'd need 5x14" posts though? Typical here in the USA, 6x6" posts 9' on center for pole buildings much bigger than that, and often designed for higher wind speeds.

The forces are different between a wood frame and a steel frame, because wood and steel have different strengths and weaknesses. A wood pole frame relies on the buried portion to keep from tipping over, that is supplemented by knee braces to the truss. Most large steel frames here are thinner at the foundation and at the peak because that joint is compression, and a thicker section at the wall to roof joint because that joint is in bending stress. You can't just design a steel foot for a wood pole based on a steel building because they're different structurally.
 

popeye151

Member
Livestock Farmer
you will be fine,

if your capable of building all the wooden part im sure you more than capable of putting a few bolt boxes down,

the idea of the 'foundation' as i understand is ballast to hold the building in place, there really not heavy say compared with a block and stone wall of a house which have much smaller sized foundations.

The std size is around 3ft square by 2/3ft deep, is it windy where you are or exposed? how bigger bays are you making, this is for 15ft bays, if your are less i would adjust accordingly.

depending on location i would be tempted not to use holding down bolts (the ones cast into the 'bolt box') just use std expanding bolts m20 just get plenty in each leg say 6.

there is no reason the bolt boxes can be finished floor level if you want them to be, just makes it neater if there below if you are concreting the shed.

pm me as stuff might be much easier to explain on the phone if you like.
hi,
yeah its pretty windy here so i want to make sure its well bolted down. thats why i was thinking to concrete in bolts. or resin maybe?

15ft bays, indeed.

yeah if your up for a chat about it that would be great. u want to send ur number?
cheers
 

popeye151

Member
Livestock Farmer
For 60ftx30ft you'll probably be fine. I can't see why you'd need 5x14" posts though? Typical here in the USA, 6x6" posts 9' on center for pole buildings much bigger than that, and often designed for higher wind speeds.

The forces are different between a wood frame and a steel frame, because wood and steel have different strengths and weaknesses. A wood pole frame relies on the buried portion to keep from tipping over, that is supplemented by knee braces to the truss. Most large steel frames here are thinner at the foundation and at the peak because that joint is compression, and a thicker section at the wall to roof joint because that joint is in bending stress. You can't just design a steel foot for a wood pole based on a steel building because they're different structurally.
5x14 is probably oversized, but i bought the frame of a friend with a sawmill. he cut initially cut the timber for himself to build a barn, but then his situation changed and he sold it to me. A major plus on this point is that he picked out all his best logs to cut the timber out of, thinking it was gonna be for himself, so im pretty confident in the timber quality.
yeah i agree, wood and steel act differently so i need to have some good bracing in place
 

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HSENI names new farm safety champions

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Written by William Kellett from Agriland

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The Health and Safety Executive for Northern Ireland (HSENI) alongside the Farm Safety Partnership (FSP), has named new farm safety champions and commended the outstanding work on farm safety that has been carried out in the farming community in the last 20 years.

Two of these champions are Malcom Downey, retired principal inspector for the Agri/Food team in HSENI and Harry Sinclair, current chair of the Farm Safety Partnership and former president of the Ulster Farmers’ Union (UFU).

Improving farm safety is the key aim of HSENI’s and the FSP’s work and...
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