Tag Archives: solar panels

Solar Panels, Concrete Free Slab, and Overhead Door Posts

This Wednesday the Pole Barn Guru discusses the possibility of installing solar panels on a pole barn roof, use of a “concrete free” slab, and overhead door post sizes.

DEAR POLE BARN GURU: Can solar panels be installed on a pole barn roof?


DEAR JAMES: Provided roof truss top chord and purlin dead loads have been appropriately adjusted upward to account for weight added by your solar panels, they can certainly be added on a ‘pole barn’ (fully engineered post frame). We have had numerous clients do just this. For some extended reading please see: https://www.hansenpolebuildings.com/2012/02/solar-panels-2/.


DEAR POLE BARN GURU: On page 32 in the February/March 2022 issue of Fine Homebuilding, is an article entitled “Inside the Concrete-Free Slab,” about building a plywood slab-on-grade floor. Are you familiar with this construction method and if so, would it be a possibility for a residential Hansen Building design. RICHARD in LEWISTOWN

DEAR RICHARD: I had not previously seen this as a design solution, however it totally works and we could certainly incorporate it into your new Hansen Pole Buildings’ barndominium. I very much appreciate your sharing this article with me (https://www.finehomebuilding.com/project-guides/insulation/concrete-free-slab).

A benefit of a fully engineered post frame building is you do not have to have continuous footing and foundation, even in using this system.

At edges, I would recommend three inches (roughly R-15) of EPS (expanded polystyrene) vertically, on inside of pressure preservative treated splash plank. Top would be set at 3-1/2″ above bottom of splash plank and extended downward two feet (in Climate zones 4 and greater, add an outward horizontal to match Frost-Protected Shallow Foundation requirements).

There are some true beauties to this system – it does away with expensive concrete for slabs, along with near impossible to find skilled concrete finishers. It will be so much easier on knees (mine scream at me when I stand too long on concrete).

Cost-wise, at current plywood prices, it looks like a roughly four dollars per square foot investment for plywood. Under plywood insulation (I would also use EPS) should be same whether concrete or wood.


DEAR POLE BARN GURU: Hello, I have a 24’x36′ pole barn that has one open 12’x24′ bay. I would like to add a garage door on that side. Looking at the closed bay, it seems fairly straight forward on products required. My only issue that I see so far is the 4″x4″ used to support the sides of the garage door itself. The closed bay side has the 4″x4″ inserted into the ground before the cement slab was poured. My only options would be to come up or locate some type of bracket that will screw in securely to the concrete pad or cut the concrete and dig down place the poles, then re-concrete that sections. Do you have any suggestion? Thank you for the help. I have supplied a photo on what I am working with. RONALD in CAMANO ISLAND

DEAR RONALD: Each side of your new overhead door should have a 4×6 column, rather than 4×4. Four inch face should be oriented towards sidewalls. Simpson Strong-tie makes several retrofit brackets – so there will be no need to cut into your existing concrete slab. Check with your local The Home Depot ProDesk as they can recommend an in stock base. Ask for a bracket with a one inch standoff, so you will not need to use a pressure preservative treated column.



Ganging Up Barndominium Roof Trusses

Hansen Pole Buildings’ client (and quickly becoming our good friend) Brett and his lovely bride are self-building their new barndominium at Cumberland Furnace, Tennessee.  For those who are like me and rely upon front seat navigator with a GPS on her phone to get anywhere – Brett is mostly West and slightly North of Nashville, roughly just under a two hour drive from our oldest daughter Bailey who lives in Shelbyville.

Their building will be 36 feet wide (clearspan) by 62 feet long with an 11 foot eave height. It has a 7/12 roof slope to allow for bonus room attic trusses. It features an eight foot wide wrap around porch across the front endwall and 36 feet down each side.

Brett’s barndominium will be plenty stout as it is designed for a 131 mph (miles per hour) design wind speed with an Exposure C (https://www.hansenpolebuildings.com/2012/03/wind-exposure-confusion/). With trusses directly aligned atop sidewall columns up to every 14 feet, besides floor weight, purlins between trusses are designed to support sheetrock as well as standing seam steel over 5/8” CDX plywood and rooftop solar panels.

In one instance his building has a four ply truss. In Brett’s words:

“Also, I wanted tech support to know the use of caulk and adhesive to assemble my attic trusses worked out really well. I also wanted to pass on a tip. Use stout welding clamps to sandwich the material prior to the nailing pattern and make sure all the metal plates are fully pressed into the wood. Levels and string were really important to keep these taller trusses behaving while using metal stakes to keep the bottom chord nice and straight. Once the first truss is good to go, all the other trusses in that series behave really well with welding clamps. These 4-ply trusses were no joke to assemble :-)”

Caulking was utilized between truss plies in order to prevent any warm moist air from inside the building rising between trusses and condensing on underside of roof deck (spaces between purlins will be insulated with closed cell spray foam).

Further Brett adds:

“I am placing the last truss together to complete my last 4-ply set. I can mock up the metal stakes, string line, and I will be using the welding clams/large c-clamps to set the final one in place with the nailing pattern. It will show how the excess caulk and glue has oozed out of each ply. Lastly, the use of a plate level/long level to show how important it is when you have this many ply-s in a set not just horizontal but vertical as well before you nail the second truss together. And because each ply is not light I placed each end of the truss on a portion of 6X6 lumber that was level with the truss each set.  (set with a laser level ) Once this is all done and weather cooperates, I will install the joist hangers and finally the bolt pattern for the 4-ply trusses and install them. And to further credit…my best helper was my wife and we managed to put them together ourselves. She has been a trooper 🙂 “

Hopefully we will see more photos from Brett as his barndominium progresses!

P.S. Note how pristine Brett’s jobsite is!

Flexible Solar Panels for Post Frame Buildings

My first article regarding thin-film solar panels was penned seven years ago: https://www.hansenpolebuildings.com/2012/02/solar-panels-2/

Reade SHEREE in MAKANDA writes:

“I have an existing metal sided and roofed pole barn that is >30 years old but still in good shape. I have been entertaining the idea of trying to incorporate solar panels onto the roof, but worry about the load on an older clear span design. Then I read about the integrated thin solar sheets and wonder if this can be incorporated as a retrofit on an existing building. Can you give me an idea if this is even a possibility?”

Possible and practical do not always provide similar answers. I am one of those who tends to leap onto new technology fairly quickly and I have yet to be able to run numbers to confirm solar energy return in savings is worth my investment.

Solar panel technology is rapidly advancing every year, and new developments like flexible solar panels are constantly being released and improved upon. 

A standard monocrystalline or polycrystalline solar panel is made up of silicon wafers. They are typically up to 200 micrometers thick, slightly thicker than a human hair. In order to make a “flexible” solar panel, those silicon wafers must be sliced down to just a few micrometers wide. Using these ultra-thin silicon wafers gives solar panels many unique properties, including flexibility for some models.

Flexible solar panels made of ultra-thin silicon cells have been around for a while. More recently, research at Massachusetts Institute of Technology has given way to advances in organic solar cells. Instead of using silicon as a basis for solar cells, researchers have found a way to use organic materials with electrodes of graphene. Until now, a limiting factor on panel flexibility has been typical electrode brittleness, but due to graphene’s transparent and flexible nature, this method may lead to thinner, more flexible, and more stable solar panels in the future than what we can currently make.

Current flexible solar panels available to post frame building owners fall under the category of “thin film panels.” A thin film solar panel is made with layers over 300 times smaller than standard silicon solar panels, giving them a much thinner profile and can even make some thin film panels flexible. Thin film panels are lightweight and durable, and can be an intriguing option depending on a solar project’s needs. 

There are very few (if any) solar installers who offer flexible panels as part of a rooftop or ground-mounted system. 

Biggest advantage of flexible panels is their ability to fit many types of solar projects. If your roof can’t bear heavier loads of traditional solar panels due to structural concerns, lightweight flexible panels like thin-film may be a great solution, not compromising your post frame building’s structural integrity. Because flexible panels can be shaped to fit surfaces they are installed on, they can be easily installed on less conventional structures like your pole barn.

Financially, flexible panels will likely reduce installation costs of your solar array. Flexible/thin film panels require less labor to install, and they are much more portable and easy to handle than typical panels, as they can be bulky and heavy and require heavy-duty roof mounting systems.

Most common obstacle for thin film or flexible solar panels is their lower efficiency than classic panels. Today, efficiency ratings for average monocrystalline or polycrystalline panels hover between 16 and 20 percent. Thin film solar panels typically offer an efficiency of between seven and 13 percent. This lowered efficiency means you will need more solar panels to produce the same energy amounts. Flexible solar panels aren’t a good fit for many rooftop solar projects, because there may not be enough roof space to produce your desired amount of energy.

Roof Loads for Solar Panels, A “Square” Building, and Post Rot

This week the Pole Barn Guru answers questions about installing solar panels on the roof, the “squaring” of a building, and rotting of posts.

DEAR POLE BARN GURU: Will a Pole Barn roof be able to hold solar panels? CARMEN in ORANGEVALE

DEAR CARMEN: We can have your new post frame building engineered to support any amount of snow load, as well as any weight of solar panels, or other materials or systems you might want to either place upon, in, or hang from the roof system, and of course the building frame which supports it.


DEAR POLE BARN GURU: We purchased our home and it has an unfinished pole barn. I was told it was stopped due to not being square by the township. What I have found is it is 18x48x14ft tall. I would like to add on to it and finish it which would require a 12×48 lean to and the rest of the materials to finish the building is this something you would consider quoting? JAMES in CEDAR SPRINGS

DEAR JAMES: Our hope will be “square by the township” merely means prior owner neglected to acquire needed permits (rather than building as constructed happens to be out of square). Before moving forward you should be visiting your township planning and building departments to determine exactly what issues exist. It could be your unfinished pole barn has been started in a disallowed portion of your property.

Once you have cleared things up with your officials, we could provide structural plans and materials for an attached lean to (again providing it meets with your Planning Department’s requirements).


DEAR POLE BARN GURU: One of my clients sent me this reply, can you sent me a link or information to answer his question: “As I have researched pole barns many folks talk about not setting the pole in concrete due to rot from water?”

Thanks. GREGG (a Hansen Pole Buildings’ Designer)

DEAR GREGG: I would sure like to see scientific proof from these “many folks”. Properly pressure preservative treated columns rotting from any cause would be just another old wives’ tale (no offense meant to old wives).

Another urban myth debunked here:




Dear Guru: Housewrap, Concrete Brackets & Wobbly Trusses

Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays.  With many questions to answer, please be patient to watch for yours to come up on a future Monday segment.  If you want a quick answer, please be sure to answer with a “reply-able” email address.

Email all questions to: PoleBarnGuru@HansenPoleBuildings.com

DEAR POLE BARN GURU: Can I set my poles, or posts, on concrete rather than set in holes?  And, can I attach floor joists across the pole building to create a floor?  The planned width is 12-16′   SOMEWHERE IN SEDRO-WOOLLEY

DEAR SOMEWHERE: The answer to both of your questions is yes.

 For further reading on brackets for the columns please read: https://www.hansenpolebuildings.com/blog/2012/09/concrete-brackets-2/

 We design a fair number of buildings which have elevated wood floors, over “crawl spaces”. Please keep in mind, any beams or girders which are within 12 inches of exposed soil, or joists within 18 inches of exposed soil, must be appropriately pressure preservative treated to resist decay.

DEAR POLE BARN GURU: The instruction book is very clear about how to install roofing insulation, but silent on the correct way to install the housewrap on the walls.  I’ve used housewrap on stickbuilt walls, over the sheathing and under the siding, but never with the wrap just floating out there in space flapping between the girts.  Any tips to share about how to do this right? QUESTIONING IN CONNECTICUT.

DEAR QUESTIONING: When installing housewrap over bare studs in stick frame, or wall girts in a post frame building, run the housewrap perpendicular to the framing. In the case of a pole building –run in tightly placed strips running up the wall from the pressure treated skirt board, to either the soffit support (with enclosed overhangs) or the eave girt (with open or no overhangs).

Don’t leave the housewrap exposed to any wind.  Similar to putting the insulation on the roof with immediately putting roofing over it – do the same thing with your housewrap. Only put housewrap on as far as you can immediately cover sections with steel. On a day with little wind, you may be able to put housewrap on an entire wall before covering with siding.  On a windy day, you may have to do 3’ sections at a time to keep it all “tight” and intact.

The housewrap manufacturers typically recommend fastening to the framing with plastic capped staples or plastic capped nails long enough to penetrate the stud every 32 inches(vertically and horizontally).

 Although you will rarely find this done in the real world – ALL housewrap seams are to be taped.

DEAR POLE BARN GURU: Regarding knee braces; most of the comments above appear related to sheathed structures. What about their usefulness on open pavillion pole barns? Have a lot of movement in one barn and am putting braces on poles to beams and to trusses to try to alleviate this. Comments or suggestions welcome. WOBBLY

DEAR WOBBLY: Unless the roof trusses have been designed to support the loads being induced into them from the knee braces, don’t do it….a high wind could cause a catastrophic failure. Usually excessive movement in pavilions is due to one or more of the following: Columns are undersized or column holes are not completely backfilled with concrete. If you can provide the dimensions of your building, as well as some digital photos, I may be able to make some recommendations which would improve your situation.

DEAR POLE BARN GURU: Do you also offer wooden pole barn designs? LONGINGLY IN LANGLEY

DEAR LONGINGLY: As all pole barns are wood framed, I will assume your question is in regards to buildings which would have wood siding. The answer is yes. Any type of siding which can be used on any other structural building frame can be used on a pole barn. Whether you are looking for sheet sidings, such as T1-11, boards or planks, any can be utilized.

 Keep in mind, wood sidings are not going to be maintenance free – they require frequent staining or painting, in order to keep from deteriorating.


DEAR POLE BARN GURU: We have a customer with an existing Hansen pole barn with a metal roof.  We would like to install solar modules on the barn, but are not sure the structure can take the additional weight and/or the wind uplift from the modules.  Where can I go for more information?  We don’t have money in the project to hire a structural engineer, so if I could find some of the original structural calculations, that would be great.  SUNNY IN SANTA CRUZ

DEAR SUNNY: Although solar panels are relatively light weight, chances are the roof structure would not be designed to adequately support any extra load over maybe a pound per square foot. If you could provide for us the information on the original purchaser of the building, we could verify the actual capacity of the roof system. Give me a call and I’d be happy to research this for you.


Solar Panels with Metal Roofing

With the latest technological advancements, innovations, and commercially viable implementation of thin-film solar roofing technology, we can now benefit from solar roofing products which offer revolutionary simplicity. Thin-film solar panels are light-weight, easy to install and can last a long time, requiring no penetrations to your roof.

Simplicity is the ultimate sophistication. One of the latest technological innovations the integration of solar roofing panel laminates with steel roofing by the use of a peel and stick method.

Mess-free, light-weight and long lasting, this energy efficient roofing solution pays for itself.

Thin film solar roofing panels are light-weight and easy to install. They are made to fit standard steel roofing panels. Thin-film PV solar panels do not require any penetrations to the roof, and can be easily attached to steel panels using a revolutionary peel and stick method.

Crystalline solar panels can generate twice the amount of electricity of the thin-film solar panels. They are, however, bulkier and use a special mounting system, which requires roof penetrations. The only exception is a steel roof. You can attach a solar panel holding brackets to the raised ribs of the steel roof.

Thin-Film PV solar panels are designed to integrate seamlessly with a steel roof. They have a very low profile, which can be a significant architectural factor. They can generate electricity even on cloudy days, in the absence of direct sunlight.

Unlike the ubiquitous asphalt shingle roofs, modern steel roofing systems are made to last and can be considered permanent. They are manufactured using a significant proportion of recycled metal content, and are fully recyclable themselves, hence qualifying as sustainable green building materials.

When a steel roof is installed by a trained professional, it will last for many decades, and thus can be a permanent platform for a solar roofing system whether it’s crystalline or a thin film PV solar.

Steel roofs combined with renewable energy technologies can create a perfect combination of light-weight, long-lasting and affordable solution for Solar Electric and Solar Hot Water systems.

There are numerous benefits to having a steel roof combined with Solar PV panels, and other renewable energy technologies. Longevity, durability, and cost savings which add up over time are just a few.

When comparing shingles and steel roofing you should also consider a steel roof will help save our landfills from getting more old roofing shingles, petroleum based products, being dumped there every time an old asphalt shingle roof gets replaced.

Steel roofing provides a permanent and energy efficient roofing solution which can generate electricity when integrated with solar roofing panels, and various other solar technologies such as solar hot water systems.  If you are considering solar roofing panels, think steel roofing for your optimal combination.  Still thinking asphalt shingles with solar panels?  See my blog from yesterday and hopefully it will give you pause to reconsider.

Building KitPrice

Know more about our pricing.

Pole Barn Guru Blog

The industry’s most comprehensive post frame blog.

Ask The Guru

This guru will grant you the answer to one pole barn question!

Pole Building Learning Center

To help guide you in the design of your new pole building.

Photo Gallery

Look at our collection of building photos for creative ideas!

Paint Your Building

Lets pick out some colors!