Tag Archives: A1V insulation

Tear Down to Rebuild? Bay Spacing, and Condensation Problems

DEAR POLE BARN GURU: Hello, I am going to tear down a 30x40x10 pole building to rebuild on my property. I noticed that the trusses are spaced 10 feet apart and are set on the 6×6 pole that has been notched. With no header board. This is an all metal building. Was wondering if this is an acceptable method of notching the post to put trusses on. Thanks. SHAWN in INDUSTRY

DEAR SHAWN: The most typical engineered post frame design provided by Hansen Pole Buildings utilizes a double (two ply) prefabricated wood truss notched into the columns (most usually spaced every 12 feet). This, in my humble opinion, is a combination which provides the best possible truss to column connection for post frame buildings, along with the reliability of the double truss system.

I would have concerns about the reassembly of a tear down, due to possible materials damage, as well as the building possibly having been designed to a no longer valid building code. My recommendation would be to contact the original engineer of record for advice as to how to proceed. If you are unable to contact him or her, then a local RDP (Registered Design Professional – architect or engineer) should be engaged to determine the structural integrity of the building as well as its adequacy to support the given climactic loads under the current building code.

DEAR POLE BARN GURU: Hello again! I reread the instructions and it said for immediate response to leave email. So I posted it above. Hello Pole Barn Guru! Wishing you a blessed day. My question is about a studded wall with double trusses. What I am trying to do is avoid having to build a 14 ft wall to accommodate a car lift. I am building a 30×50 shop. The garage doors will be on the 50 side. My thinking is build stud walls and frame in laminated posts to resemble a 6×6. They would be set at 10 widths to accommodate a 10×10 garage door. This way I could set the trusses and have open overhead bays between the trusses to accommodate the car lift and not have to build 14 ft walls. Would the idea of double trusses work in this type of build? TONY in ATHENS

DEAR TONY: If you are starting from scratch, why not just construct an engineered post frame building and columns and double trusses approximately every ten feet? I say approximately as a 10 foot width residential overhead door requires roughly 10’1″ of width between the columns. We can design a building for you, which would not have bottom chord bracing between the trusses in the bay where the overhead door would fall – thus allowing for extra headroom for your car lift. You will certainly get the most for your building investment by using post frame design.

In the event you are already constructing some other sort of building, you should consult with the Registered Design Professional (RDP – registered architect or engineer) who designed your building, as he or she would need to make the appropriate alterations to ensure the structural adequacy of what you have in mind.

In any case, for the sake of safety, do not attempt to do design work on your own – entrust it to a RDP.

 

DEAR POLE BARN GURU: I have a pole barn in Colo Springs.   I have pretty bad ceiling condensation in the winter.  The prior owner just stuck R-36 up there.  I am thinking of removing each roof panel and putting Rufco Vapor Barrier and putting the metal roof panels back down. 

I would prefer to do it inside with a radiant barrier but that will probably not work.  Any suggestions?  Something better than Rufco?  Thank you. FRANK in COLORADO SPRINGS

Reflective InsulationDEAR FRANK: On your existing building – while Rufco is an excellent vapor barrier, it will not stop condensation issues, as it does not provide a thermal break. If the prior owner installed the batt insulation in the plane of the ceiling, I would recommend the use of closed cell spray foam on the underside of the roof steel. This would eliminate having to remove and reinstall the roof panels. If this is your only option, Hansen Pole Buildings does provide a reflective radiant barrier in six foot net coverage widths with a tab on one side with an adhesive pull strip for easy sealing of laps. You might give this a consideration.

 

How to Install Reflective Radiant Barriers

Today I surprise my readers with an actual “how to”!

Proper vapor barriers and ventilation system design and installation are important to prevent condensation and resulting problems from moisture damage.

Condensation occurs when moisture laden air comes in contact with a surface temperature equal to or below air dew point. This phenomenon creates problems which are not unique with steel covered buildings. These problems are common to all construction types.

Any metal roof underside is to be protected from condensation by insulation, which reduces condensation forming potential on panel undersides.

Most Common Mistakes:

  1. Overlapping reflective radiant barrier rolls (other than the appropriated side tab).
  2. Cutting off at eave girts to create “waste”.
  3. Placing reflective radiant barrier in overhangs (beyond column building lines).
  4. Not placing roof reflective radiant barrier under all steel roof surfaces within building lines (including roof only shed or carport areas).
  5. Failure to square roof plane before installation.
  6. Not straightening eave purlin to a string line before installation.
  7. Failure to adequately seal joints, rips or tears in reflective radiant barrier.
  8. Not using roof reflective radiant barrier.

Reflective InsulationWhen installing, reflective radiant barrier either A1V or A2V (white vinyl on one side), white vinyl side will face the building interior (with few exceptions).

Side bar – what is all this A1V type terminology anyhow? The “A” or “V” are the facings – aluminum or vinyl. The number 1 or 2 corresponds to the layers of air cells which are sandwiched between the facings.

A package insert may give directions for installing reflective radiant barrier. The directions refer to “airspace”. This is not the airspace on building inside. The “aluminum” reflective side is installed facing the steel (sunny side up).

Reflective radiant barrier installation does not change construction methods. Reflective radiant barrier facings are not affected by cold temperature. Except for underneath a concrete slab, reflective radiant barrier is not to be overlapped. Depending upon product received, install by one of the following methods.

Prior to of any roof reflective barrier installation, make certain roof planes have been squared.

Reflective radiant barrier is not placed in overhangs. If reflective radiant barrier is installed in overhangs, there will be a SHORTAGE !

Start roof reflective radiant barrier at same end of building roof steel installation will start. The reflective radiant barrier roll end begins flush with eave purlin outside edge (also known as eave girt). The reflective radiant barrier leading “long” edge begins flush with building end truss outside.

Reflective radiant barrier is installed to run eave to eave over ridge. Splices, if needed, are best made directly on purlin tops.

Other than to make a roll end square, do not trim the starting edge. Start flush at eave purlin outside edge. Opposite end is cut flush with opposite eave purlin outside edge (or ridge purlin upper edge for translucent or Vented Ridge applications).

Verify adequate material exists before trimming off large amounts.

Using a minimum 5/16” galvanized staple, staple through reflective radiant barrier to eave purlin top. As an alternative to staples, 1” galvanized roofing nails (with the big plastic washers) also work well. Roll out reflective radiant barrier across purlins (up and over ridge) with aluminum side up and white side down (towards building inside).

Pull reflective radiant barrier past opposite eave purlin edge and staple to top. Trim roll off flush with opposite eave purlin outside edge.

As an alternative, double-faced tape may be used to attach reflective radiant barrier to eave girts.

Install next roll in same manner, stretching roll tightly, align properly and close butt sides.

For reflective radiant barrier with an “adhesive tab” (typically A1V): These have a 1” tab (without air cells) extending along one reflective radiant barrier roll long side. At the seam, where two reflective radiant barrier rolls are joined, pull tab across adjacent roll by 1”, remove “pull strip” from the adhesive, and firmly press the two rolls together. Properly installed, each roll will have a 48” or 72″ net coverage, depending upon product purchased.

For square edge rolls, use a butt joint and seal seams properly with tape. (Good to Know! A butt joint is where two pieces are placed end to end or side to side without overlapping.)

Foil tape (for A1A or A2A – faced both sides with aluminum), 2” white vinyl tape or a silicone bead can be used to make permanent seams between ends and reflective radiant barrier roll sides.

For maximum air and vapor tightness, keep perforations in reflective radiant barrier to a minimum. Seal all perforations with reflective radiant barrier tape.

If this process sounds like work, it can be! A far less labor intensive solution for condensation can be read about here: https://www.hansenpolebuildings.com/2014/07/condenstop/

Will Kilz Paint Stick after a Fire?

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: I`m building a 24’x36’ workshop and I want to know if I`m putting materials in the right place/order. I have 2×6 constructed walls with NO osb, 12’ high that are bolted to my slab. I plan on wrapping the walls in house wrap, putting my 2×4 girts on top of the house wrap and then metal siding over the girts. I`m wondering if 1 ½” space created between the metal siding and the house wrap would pose a problem?

On the inside I plan on fiberglass insulation up against the backside of the house wrap, then vapor barrier and then metal interior panels. IS this ok?

As for the roof, I was reading on your site about the reflective insulation from “www.buyreflectiveinsulation.com” and I went ahead and got the A1V and I plan on putting that down on top of my 2 foot spaced 4/12 trusses and then roof metal. These are common trusses so I will have a ceiling with blown in insulation on top of that. I`m just trying to avoid condensation, I will have 36’ breathable soffits on each eave and I am putting vented closure strip on the peak. I plan on heating the building on an “as needed” basis and I live in SE Wisconsin.

Is there anything wrong with the way I`m going about this? Is the house wrap on the walls even necessary? I`m doing all the work myself and trying to save as much money as possible but I know I only have 1 shot to get it right.

Thanks for your time. RICK

DEAR RICK: It sounds like you have studwall framed your workshop. If this is the case and your walls are 12′ tall, I hate to be the bearer of bad news – you do have a structural problem. Table 2308.9.1 of the Code (https://publicecodes.cyberregs.com/icod/ibc/2012/icod_ibc_2012_23_par170.htm?bu2=undefined) limits the height of load bearing stud walls to 10′.  Before going further, it would behoove you to consult with a Registered Professional Engineer to resolve the structural issues.

Moving forward –

With insulated walls, housewrap is an excellent idea and the 1-1/2″ space between it and the siding should pose no negative issues.

My personal choice for interior wall finish is sheetrock – it is less expensive than steel, absorbs sound, easier to attach things like shelves, cabinets, work benches, etc. A dent in a steel panel cannot be repaired, a dent or hole in sheetrock is easily fixed.

On your roof, with trusses two foot on center, you will need to lay 2×4 flat on top of the A1V and the trusses. The 1-1/2″ dead air space created by the 2×4 will actually improve the thermal efficiency of the system. If you have not yet ordered trusses, I’d recommend buying ones with raised heels to increase energy efficiency and reduce potential heat loss: https://www.hansenpolebuildings.com/blog/2012/07/raised-heel-trusses/

Be sure to use screws to attach the steel and use the right size screws in the right locations: https://www.hansenpolebuildings.com/blog/2014/12/screw-placement/

Mike the Pole Barn Guru

DEAR POLE BARN GURU: Have a pole barn that we used the prefinished pole barn steel panels for ceiling. Had an auto fire close to the ceiling. Replaced buckled panels and had a ServPro (https://www.servpro.com/) fire restoration company clean rest of panels of loose soot. They say Kilz paint primer will stick and seal the smoke residue so paint will adhere and stay. What do you think and recommend? ANTHONY IN MEDFORD

DEAR ANTHONY: With a fire producing extreme enough heat to have buckled steel ceiling liner panels, I am hoping your insurance company had a Registered Professional Engineer do an inspection of the roof trusses to ascertain if they were damaged. While the wood trusses may not have been exposed to the direct flames, the heat from the fire could have caused the lumber to shrink away from the steel truss connector plates and/or the plates could have lost their temper from the heat. If they did not, I would suggest it be done now, before a problem occurs which was unforeseen.

Provided the roof system was designed to support the weight, I would originally have recommended removal of all of the steel liner panels and replacing with 5/8” Type X Drywall. Read more about why here: https://www.hansenpolebuildings.com/blog/2013/08/steel-liner-panels/

The 5/8” Type X drywall is also fire resistant.

As you are past this point – Kilz paint (https://www.kilz.com) does make products which will adhere to the steel liner. I’d recommend a visit to the paint expert at your local The Home Depot®, where they can give you not only the proper advice on which Kilz®paint product to use, but also can make you a smoking hot (pun intended) deal on it!

Regardless of what product is used for painting, it is essential to properly prepare the steel surface prior to priming with Kilz paint. More information on repainting steel panels is available at: https://www.hansenpolebuildings.com/blog/2013/01/repainting-steel/

Mike the Pole Barn Guru

DEAR POLE BARN GURU: Good morning, Guru,I am an engineer and I am looking at a pole structure approximately 40 years old. First, is there a formula (given all the variables) to estimate the vertical load capacity of the poles? Second, being 40 years old, what is the likelihood there are footings at the base of the poles? Was it common practice to use footings in the mid-70s?

The sooner you can respond, the better.

Thanks in advance for your help! BOB IN MADISONVILLE

DEAR BOB: There is a formula which will calculate the capacity for the columns – which must resist both bending and compressive loadings. We’d be happy to check them for you, for free.

We would need to know the actual dimensions of the columns, as well as the species and grade, and their on center spacing.

From the building we would need to know the eave height (https://www.hansenpolebuildings.com/blog/2015/02/eave-height-2/), width and length, as well as roof slope and whether the columns are adequately tied into the concrete slab or not. We also would need to know if the siding and roofing are properly fastened so as to provide a diaphragm, as well as the materials used. Also is building fully or partially enclosed and are doors designed to support wind loads.

Digital photos of as much of the structure as you can provide would prove helpful.

Climactic information we would need includes ground snow load, use of building, if building is heated, design wind speed and wind exposure.

Lots of variables to consider, all of which we have checked by our proprietary program every time we even quote a building.

Footings – as most pole buildings currently being constructed have inadequate footings, do not count on this one being an exception. If you are potentially going to have a liability for them, I’d certainly recommend digging to the bottom of one or more of them to ascertain what indeed is really there.

Mike the Pole Barn Guru

We Ran Out of Insulation

Most of the steel roofed pole buildings supplied by Hansen Buildings include a reflective radiant barrier between the roof purlins and the roof steel to prevent condensation issues. Interested in more information on this product? Visit our page on the reflective radiant barrier difference.

Surprisingly (or not surprisingly) very few DIY building owners ever run short of insulation, the cases where a shortage comes up is generally when a builder is hired to do the erection.

Each chapter of the Hansen Buildings Construction Guide begins with listing the errors encountered from previous installations. When it comes to roof insulation here is the list:

1. Overlapping insulation rolls.

2. Cutting off at eave girts to create “waste”.

3. Placing insulation in overhangs (beyond column building lines).

4. Not placing roof insulation under all steel roof surfaces within building lines (including roof only shed or carport areas).

5. Failure to square roof plane before installation.

6. Not straightening eave girt to a string line before installation.

7. Failure to adequately seal joints, rips or tears in insulation.

8. Not using roof insulation.

 

One of the Hansen Pole Buildings Designers was recently speaking with his client, about their newly completed building and reported:

Customer says he came up short A1V and had to pay another $299 to buy more locally. He would like to know if the 4 rolls he received was the appropriate amount.  If so, he concedes the builder may have applied incorrectly.  If he was supposed to get more, please dig a bit deeper there.”

This particular building was a “monitor barn” – 12 foot wide wings on each side of a 16 foot wide raised center.

When we receive reports, such as these, my first instinct is we must have done something wrong. So, I go back to the beginning and work my way through, to determine, if indeed, this is the case. I always make sure I give every client the benefit of the doubt.

The length of the insulation in the wing roofs (measured with the run) was 12.773 feet

The raised center roof was 17.114 feet

12.773 + 17.114 + 12.773 = 42.66 feet

42.66 feet x 48 feet of building length = 2048 square feet to cover

The insulation rolls are supposed to be four feet wide by 128 feet in length, or 512 square feet.

2048 / 512  =  4 rolls
Here is where recent real life practical experience jumps in…

Having just put up a building myself (you may recall the recent adventures of Steve’s new garage), I was quite surprised to find out the 128 foot long rolls are actually several feet longer – we cut eight pieces 16 feet long from each roll and had probably 8-10 feet of left over from each!

My educated guess…..one or more of the “most common mistakes”, was utilized.

It is a shame $299 was paid for a roll locally as our price is far less, even with freight.  And the local roll most assuredly did not have the adhesive tab on one side, which makes installation a breeze.