How to Build a Grain Bin--Roof, Peak Ring, Lid, Safety Ring, and Roof Ladder: An Illustrated Guide
A Finished Roof and First RingClick thumbnail to view full-size
Overview of Process
For building the roof, you will need a crew of two or members. Three or four can be better. Hopefully at least one member is spry and resilient.
Building the roof may take up to half of the total time for the bin. For a small or medium bin, this averages 5 to 6 hours of intense labor . . . so the roof may take you two to four hours, even if you know what you are doing.
Process for Sheets
The process is usually straightforward for a smaller bin. You begin by fixing the inner collar or peak ring to your lifting ring. Four roof sheets are then attached to this, in opposite pairs, so that stability is built as quickly as possible. Roof sheets are fragile! It is easy to dent or bend one. Their final stability and strength come from their dome shape. In order to reach the peak, you will need to work off a tall step ladder, or scaffolding.
Next, panels are added in a balanced manner, filling in the gaps in opposites, until you are left with last a gap where the sheet including a manhole will fit. Hardware is added loosely at crucial points, to be filled in and tightened later.
Before installing the last sheet, it is best to build the roof ladder.
The last sheet is now installed, and may be tricky, since manueverability is at a minimum.
If you plan on lifting your bin from the top with a crane, etc., you need to assess the collar strength. If your bin is supplied with many bolt holes in the bottom piece of the collar (peak ring), it is time to move on to the next step. If not, you will need to drill some more and install and tighten hardware. One bolt per sheet is a good starting point. Otherwise, your bin may tear away from the collar during construction, and fall, potentially maiming or killing someone. If in doubt, strengthen the collar.
Process for Safety Ring, Collar, and Lid
Manufacturers vary in their methods of constructing and fitting the safety or wind ring, the top peak ring or upper piece of the collar, and the lid. Your manual will give you clues as to the process you should follow.
On average, the wind ring is installed 2 holes down on the roof sheets. Keep this in mind when plugging in bolts. Check your manual for variations of this. It is bolted together in curved sections, to make a place to stand when accessing the lid.
The collar is next. It may go on hard, requiring two people to handle and fit it.
Lids have many variations in how they go on and latch. Consult your manual for tips. You may need to field drill some holes, depending on the construction. You may need to put on your puzzle-solving brain.
Easy Work Days Due to Wind
We put the bin featured in this article up in easy sessions over three days, due to weather patterns. We all had other jobs to attend to, so worked a couple hours in the early mornings, secured the bin until the next session whenever the wind came up too strong, and got on with our day.
A grain bin is not worth anyone's limbs or life. If weather interferes with your building plans, let it.
T-posts Block Bin in Place Temporarily
Tools Needed for This Stage
- Lifting ring or large truck rim
- Lighting if working at night
- Drift punches, medium length (10 inches at least)--1 minimum for each crew member
- 9/16-inch box-end wrenches (2 at least), with long handles
- High quality impact wrench, as you will give it a work-out
- Hearing protection--preferably ear-muff or electronic type
- Drill and appropriate metal bits, for field drilling bolt holes in roof components
- Permanent marker, black wide tip
- Work gloves which allow for dexterity (optional)
- Comfortable work boots with decent tread, hard toes optional
- Work clothes which will not snag or allow you to get hurt easily
- Vice grips, high quality
- Slipjoint pliers (optional, but can be handy)
- Tape measure, standard
- Ladders, 6 foot and 8 foot tall minimum, depending on the size of the bin--for building the roof
- Scaffolding--an alternative to ladders
- Tool pouch/apron, or coffee cans/small buckets for hardware (a small pouch is annoying as it must be refilled often, and is hard to reach into)
- Mastic (a sealant for between sheets). Mastic can be found using the search words: Single Bead Tape Roof Sealant Metal Sales
- A way to block wind from swaying or sliding the bin during work (we often use a semi truck and trailer)
- T-posts for driving in around the partially built bin during off-hours, or a suitable way to weigh the bin down at the peak (i.e. the boom of a boomtruck or crane)
- Forklift, ATV, or another way to move the sheets and other materials onto the jobsite
Transporting Fragile Roof Sheets Safely
Roof sheets are fragile. They are generally of a light gauge, and their strength comes from their construction formation, not from their individual design.
Bear this in mind whenever you transport roof sheets. We prefer to set them on the forks of a skid loader or tractor while moving them or prepping the site for the day. At the least, they need to be set on a good pallet or blocks to keep them straight and off the ground.
Roof Sheets on Skid Loader ForksClick thumbnail to view full-size
Begin With Four Sheets
The lifting ring is centered with the collar stabilized on it, and hung at the estimated peak height. If you are not using a lifting ring, as when using jacks, you will need to figure out how to stabilize the collar some other way, or have someone with a lot of stamina hold it for a very . . . long . . . time, while perched on a ladder or scaffolding.
Your manual may give you hints as to alternate methods.
You will begin with four roof sheets installed in a spoke formation, bolted to both the collar and first ring of wall sheets.
Setting Lifting Ring; Starting Formation of SheetsClick thumbnail to view full-size
Main Sheets Get Filled in Next
After four sheets are installed, you will add one roof sheet per section, strengthening the formation systematically.
Continue in this fashion until almost all roof sheets are installed. Leave one gap in each section, and install bolts and nuts along the seams loosely for now. Being able to reach seams from more than one angle is helpful, so do this as you are able.
Now fill in all sheets except the manhole, or one gap to use as a door. Finish filling in all hardware that is convenient to reach. The last sheet in each section may go in hard, as it will seem to fit tighter because there is less room to manoever.
The manhole sheet is generally installed last.
Be sure to leave bolt holes free where the roof ladder will be placed. Bolts may be inserted backwards as reminders not to plug these normally or tighten them.
Removing Lifting Ring
At any point you are sure the roof is strong enough to stand on its own without risk of damage, you may lower the lifting ring and get it out of the way. Whether to leave it until the roof sheets are completely installed, or take it out early may depend on wind conditions. Be safe. Working around the lifting ring may slow you down a little, but it will provide stability.
Installing the Main SheetsClick thumbnail to view full-size
Erecting a Big Grain Bin--Hydraulic Jacks--Part 1
Installing Roof Ladder
In general, roof ladders are simple. Angle iron rungs are bolted to righ ribs next to the manhole sheet, using bolts including steel-back neoprene washers.
Wherever a safety ring will be installed, a ladder rung will generally be missing, as the ring will complete the steps. Consult your manual to be sure where your safety ring(s) will be placed. On a bin this small, the second-to-top bolt holes generally mark its placement.
While roof sheets are being installed, bolts may be inserted backwards as a reminder of the ladder's placement, so bolts are not accidentally tightened down in these holes.
Once the ladder is in place, bolts are tightened to a high torque, as you definitely don't want a loose ladder.
Roof LadderClick thumbnail to view full-size
Calm vs. Breezy Weather
If the weather is calm, the lifting ring may be taken out or lowered before all the roof panels are installed. Since it is inconvenient to work around, you will want to remove it as early as possible. Below is a sequence of photos from a different job, but with an identical bin. During this job, the lifting ring was taken out partway through building the roof.
2nd Example--Removing Lifting Ring; Installing Last Sheets and LadderClick thumbnail to view full-size
Is the Collar Strong Enough to Lift the Bin Without Tearing?
If your collar has fewer than one bolt hole per roof sheet, you can assume that it is NOT strong enough to support the weight of the roof and wall sheets as the walls are being built. A failure may result in the sheets tearing away from the collar, possibly dropping a partially-built bin on a crew member, potentially cutting him in half. So be safe. If in doubt, strengthen the collar by adding more bolts.
We had to field drill more holes in the collar so the whole structure could be lifted by a crane, etc. without undue risk. We drilled three times as many holes in our lower peak ring as were present from the manufacterer, and added bolts going through collar and sheets.
Having one hole per roof sheet is a good starting place. If in doubt, drill more.
This job is best done by two people, as it can be difficult and frustrating.
Adding Bolt Holes to CollarClick thumbnail to view full-size
Safety Ring Notes
Most safety rings simply bolt together in sections, following the curve of the roof, and being bolted to the roof through holes that match in the ring and roof panels.
The ring is installed after the roof ladder is in place, and before other work is done on the components at the peak.
The ring shown here needed some modifications in order to fit correctly, as it was the wrong size for this 18 foot diameter bin. Later on, we show how we resolved this problem.
Safety or Wind Ring InstallationClick thumbnail to view full-size
Tightening Wind Ring (Safety Ring)Click thumbnail to view full-size
Peak Ring (Upper Collar) Installation Tips
On this collar, there is nothing special about installing the upper ring. It bolts on simply, and all we had to do was align bolt holes. Tighten hardware thoroughly to a high torque once all bolts are in and finger tight.
The installation job was made easier with two people, as the ring is unwieldy, and the bolt tightening process is simpler with two pairs of hands.
Some bins do not include an upper peak ring.
Upper Peak Ring InstallationClick thumbnail to view full-size
Lids vary a lot from one bin era and manufacterer to the next. Consult your manual for tips on the design of your particular lid.
We had some trouble with the lid featured here. While the concept of this lid with its slide bar was effective, we failed to perfectly align all collar and lid components. We made the situation work, but it took extra time, work, and thought.
Study the lid and peak ring of your bin while you are alert and high-functioning to be sure you understand the design, and intended placement of all components.
Fitting LidClick thumbnail to view full-size
Installing Lid LatchClick thumbnail to view full-size
Hardware Tightening Specifications
How much to tighten the nuts is determined by the size and grade of bolts, as well as their position. Please refer to your manual for torque specifications.
For this bin, the bolts were 5/16-inch, and their steel quality was 5 grade.
5/16-inch 5 grade bolts=18 to 19 foot pounds for roof hardware.
In general, you want to tighten the nuts until they are singing soprano.
Listening carefully will soon allow you to determine by sound how much is just-enough versus too much torque. Try not to strip bolts, but don't under-tighten them, and so give yourself problems in the future. Leaks are no fun to fix, and nobody wants spoilt grain (or a leaky grain bin home).
Bolt Tightening Overview
When tightening bolts on the main roof sheets, as much as possible go up the seam on one side, and down on the opposite side of each sheet, using a drift punch inserted through a bolt hole to center the top of the seam.
Certain sections near top and bottom may need to be done on their own.
The collar underside gets tightened last, to a high torque, as it literally holds the roof together and forces it to maintain its strength-giving cone shape.
As with the wall sheets, one person runs an impact wrench inside, and another uses a box-end wrench to hold bolt heads steady outside. A flexible person who doesn't mind climbing is best to have on the roof. Someone with good shoulders is nice to have inside, as using the impact wrench above your head can be painful and exhausting.
Tightening Remaing BoltsClick thumbnail to view full-size
Wrong Spacing With Factory Holes (Mistakes Happen)!
Once in a while the people at the factory make mistakes, and on more than one job, we've had to drill holes where the manufacturers had drilled with incorrect spacing or insufficient diameter. Below we show corrections on a wind ring.
In this case, it seems that the wrong ring was sent. It was sized for a different diameter bin, so none of the holes matched those in the roof sheets.
Wind Ring/Safety Ring CorrectionsClick thumbnail to view full-size
Newer Lids' Safety Features
The bins featured in this article were manufactured in 2016 or before. Since then, advances in technology have allowed lids to become safer to operate.
In newer models, a spring mechanism on a cable allows the lid to be opened without anyone ever climbing onto the roof.
Stairs Type Scaffolding
For medium to large bins, rolling stairway scaffolding systems are the safest way to go. These may also be used to build bins over pits, as the outer edge of the stairs can sit on the foundation rim inside the bin. Below is a popular system which is similar to one my husband used on some jobs.
Bainter Stairway Rolling Scaffolding
Installing Roof Vents on a Grain Bin
The following photos were found in a forum thread discussing the building of a grain bin house. I had a moment of shock when I came across them while searching for something else, as the improvised roof supports look as if they are likely to result in injury.
Upon inspection, it became clear that these folks did what they had to to get their house up, using what resources they had within reach. But if you can do better, please do! Just because no one got killed and the grain bin is still standing, does not make these heart-stopping alternatives a good idea.
Bad IdeasClick thumbnail to view full-size
Previous and Next
- How to Build a Grain Bin--First Ring of Sheets: An Illustrated Guide
Photo tutorial showing how to build the first ring of sheets on a grain bin. Includes tips and tricks.
- How to Build a Grain Bin--Main Rings and Ladder: An Illustrated Guide
A step-by-step guide to building the main rings and ladder(s) of a grain bin ("silo"). Other parts of the bin are dealt with in separate articles.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2020 Joilene Rasmussen