Tag Archives: condensation control

Quonset Hut Homes

With the proliferation of barndominiums, shouses and post frame homes there is always someone looking for a cheaper answer. I have found cheaper generally gets me exactly what I paid for – cheap. Well for some, cheap may be living in a Quonset hut.

Considering a Quonset building for your new home? Consider resale value – there are very few people who want to live in a Quonset!

You may have heard Quonsets advertised on television, radio, online (even on Ebay) and in  back of Popular Mechanics.

I came across this query from a gentleman from Wake Forest, NC, “I have found some really good deals on the local craigslist from private individuals who have bought them and never put them up for one reason or another.” He wanted, “…to hear anyone’s input, good or bad. Yes, there are a lot of horror stories out there about poor schmucks that got hosed trying to buy from some less-than-scrupulous purveyors of these structures, but like I said, I plan on purchasing from a private individual who already has it in his possession.”

Now all of this got me thinking, so I started my research. It turns out Quonset huts were named for where they were first manufactured – Quonset Point, Rhode Island. First built for our Navy in 1941, as many as 170,000 Quonset huts were produced during World War II.

According to Wikipedia, “The erection of Quonset huts has been banned in the US state of Alaska for many years due to so many already being in the state and the majority of those falling into disrepair and becoming environmental hazards.”

I’ve never been involved in construction of a Quonset hut myself, as my background is in conventional stick frame and pole buildings. Due to this, I relied upon the experiences of four people.

When I was a post frame building contractor, Jay and his crew subcontracted labor on several pole barns we sold. Jay also did concrete work. On his own, he contracted to do concrete and assembly of a Quonset for a golf course driving range not far from me. This building was 40’ x 60’ and they worked on it every day for a month. Jay’s comments were anything but positive about concrete requirements and he said, “I’ve never seen and installed so many bolts in my life”. Of course when up and done, it had no endwalls, so those had to be constructed, and round walls precluded anything from being attached to them (not to mention it was near impossible to insulate.)

This insulation issue brought me to a comment from a Bob in Paisley, PA, talking about a local feed store, “The feed store has had issues with theirs and the original owner said it was a bad choice. They had a company come in and spray adhesive type insulation to the entire inside. As the metal expands and contracts portions of the insulation failed to follow the same rates which in turn resulted in chunks of reflective insulation falling from the ceiling area. Condensation and drips formed after the insulation fell.”

A second experience was told to me by one of my oldest daughter Bailey’s friends. Her friend’s father bought a Quonset for a garage. The pieces for it lay in a pile next to their house for several years, untouched. He finally sold it.  I can only surmise from comments it was quickly discovered to be far too much work to erect it, once purchased.

Online, I found this post from a gentleman who was actually espousing how wonderful Quonset buildings are:

“One of the few frustrating things about our Quonset is water leaks. The shell itself is engineered to be completely watertight. But, as with most well-planned projects, reality has a way of challenging the ideal. After checking all the bolts and tightening a few, we were able to seal all but a couple of leaks. The remaining few were due mainly to small tears in the metal at the bolt holes caused by over-stressing the skin in an effort to line up holes. After we made these mistakes a couple of times we realized our errors and corrected them. But the damage was done. 

Our biggest problem was sealing leaks at the base, where the shell meets the concrete and where it ties into the base plate. We were advised to fill the void created by the shell meeting the channel with concrete, which we did. We also used a heavy application of caulking between the base plate and the concrete. In spite of this, when it rained, we had an indoor pool. We then caulked all around the concrete where it met the metal. It still leaked. We then coated the whole area with water-stop concrete, a kind of latex/cement material that is supposed to seal concrete and bond to metal…it still leaked. We caulked again…to no avail.”

Lastly, one of our former Building Designers, Paul, related from his personal history as a Quonset salesman. His words were, “Less than 50% of the ones sold, are ever constructed.”

My summation is – even if they were easy to construct, Quonsets generally come in a single color – galvanized. They are difficult to insulate, with condensation control certainly being an issue. The purchase price often does not include endwalls, and certainly not doors (and sometimes not even delivery). And, speaking of doors, how do door and window openings work with curved (or even extremely high ribbed) sides? In Bob’s words, “Unless you get one of the tall ones you end up with an area along each of the sidewalls that becomes unusable except for collecting junk on the floor. Then it can be a head banger along the wall whenever you walk directly toward it while looking down for the junk.”

If anyone has a great, glowing story about Quonset huts, I’d love to hear it, I really would.  Because so far, I’m not impressed.  But I am always willing to listen to….”the other side of the story.”  Obviously I’m looking for objective evidence from those using quonsets…not just those selling.

Condensation Control, Home Plans, and Grade Changes!

DEAR POLE BARN GURU: If I put double bubble under metal on roof for condensation control, then insulate bottom chord of trusses with white vinyl faced insulation , will this create a problem if I ventilate attic space ? Thanks. SCOTT in DUNLAP

DEAR SCOTT: You actually have several things going on here. First, single bubble reflective radiant barrier will do everything double bubble will, at a far lesser investment. The difference in the minimal R value is a fraction of one! Your building ceiling should not have an additional vapor barrier, you want the moisture from inside the building to be able to migrate through into the ventilated attic space. Blowing in an appropriate thickness of fiberglass or cellulose insulation will be far more effective, probably less expensive and will allow the moisture through. Make sure to have adequate intake at the eaves and exhaust at the ridge to be able to properly vent the dead attic space.

DEAR POLE BARN GURU: Hello!

Do you all also finish the interior of pole barns if we want it to be a home or would I contract that separately?

Thanks! TIFFANY

DEAR TIFFANY: Thank you for your interest in a new Hansen Pole Building. We provide the custom designed plans, materials delivered to your site and assembly instructions for the shell and load supporting portions of your new building only. Any interior walls and/or interior wall finishes would be up to you to contract for.

 

 

DEAR POLE BARN GURU: Can I build a pole building home in the side of a hill, where the back will be below grade and the front above. RICK in CLEAR LAKE

Post Frame HomeDEAR RICK: Most certainly you can. I have a post frame building on the back of our property outside of Spokane, Washington. The site has 12 feet of grade change across the 40 foot width. After excavating the area where the building would be placed to level, ICF blocks were placed 12 feet high along the southern wall, stepping down with the slope on the east wall, with the other two walls being “daylight” and utilizing traditional columns embedded in the ground. You can read more about my building here: https://www.hansenpolebuildings.com/2013/06/garage/

 

Loosening Roof Screws

Help! My Roof Screws are Loosening!

Ask The Pole Barn GuruOur office gets all sorts of phone calls. Besides those clients who are potential investors in new post frame buildings, there are those who have made mistakes (or had builders make them on their behalf) and are looking for fixes.

 

 

One call came in earlier this year to Hansen Pole Buildings’ Designer Rachel, who wrote:

“Guy called wondering about buying insulation from us. He was looking for fiberglass. He asked some suggestions and said he has a little issue in his roof.  He has blanket insulation and said his screws are loosening.  I told him I thought it may be the insulation was too thick and the screw was not tight to the framing.  He understands but is wondering what the suggestion may be.  Wondering if he should replace all the screws?  Told him I thought it would still be an issue but not sure.  Thoughts?”

The caller’s building has a product known as metal building insulation under his roof steel. This insulation is most typically a six foot width roll of thin fiberglass insulation usually bonded to a white vinyl vapor barrier. This insulation is installed over the roof framing with the faced side down (fuzzy side up) then the roof steel is applied on top. Installed properly, with the seams tightly sealed (which rarely occurs) and any rips taped, it does make for a fairly effective condensation control.

It also makes for a lousy insulation solution, as the fiberglass is compressed nearly to nothing as it crosses each roof purlin. I’ve heard of builders selling metal building insulation as thick as six inches and trying to convince (and often getting away with it) clients they will achieve an R-19 insulating value!

All of this fluffy insulation wants to cause the roof steel to bend upwards in between the roof purlins, in some instances beginning to look like the Sta-Puff Marshmellow Man. Between this and the compressed fiberglass at each purlin – stress is laced upon each of the roof screws. If the screws are relatively short in length and/or small in diameter, they will eventually work loose (and cause leaks).

Reflective InsulationThe best solution (although time consuming) would be to remove the roof steel and the metal building insulation, replacing it with a reflective radiant barrier and placing the steel back on the roof using larger diameter and longer screws.

If the building owner is willing to accept the look of what he has, he could attempt a fix just by changing out the screws.

The best solution truly would have been prevention – not having used metal building insulation to begin with.

Should a Treated Post Look Treated all the Way Through?

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 am currently constructing a pole building. I’ve drilled holes through the columns for rebar hairpins to be inserted to tie the columns into the concrete floor. It appears the post isn’t treated all of the way through. What can I do? DRILLING DOUG

DEAR DRILLING: Pressure Preservative Treated lumber does not have to be treated all the way through to be properly treated. As long as the column is tagged as being UC-4B, the column is adequately treated for structural in ground use.

For rebar hairpin holes, after properly marking on every treated post, drill each one using a 5/8” bit. Galvanized re-bar is recommended. If not available, coat rebar penetrating column with an asphalt emulsion, or similar, to isolate re-bar from the pressure treated post. NOTE: #4 re-bar is ½” diameter. Cut re-bars into 5’ long segments and insert one through each column, centering the five foot length in hole. Bend rebar legs, by hand, to a 45 degree angle with skirt boards. Seal rebar, into bored holes, at each column edge with silicone caulking.

DEAR POLE BARN GURU: I read your articles on both reflective heat barriers and vapor barriers.  It seems they conflict somewhat in that for the vapor barrier article you suggest putting the vapor barrier between the purlin and the metal roof, but for a heat barrier you recommend a gap between the roof and heat barrier.  So how do I combine the two?  Would putting a double aluminum sided closed cell barrier like Prodex on the inside of the purlins (creating a substantial gap from the roof) work best?  Thanks in advance for your expertise. TRYING IN TENNESSEE

DEAR TRYING: Thank you very much for reading my articles. As long as the reflective radiant barrier is totally sealed, it should work quite well for both insulation and condensation control.

What House Wrap is Good For

Over the past three decades, house wrap has become a staple feature on millions of buildings. Wrapping a wood framed building in a protective envelope is a good building practice which helps combat a building’s worst enemies: water, moisture and air infiltration. House wrap behind a building’s siding is an excellent secondary defense against the weather.

House wrap is a weatherization membrane which provides a protective layer under a building’s siding and over the wall girts or sheathing. It is literally wrapped around a building, cut out around windows and doors and taped at the seams.

The unique, nonwoven-fiber structure of house wrap resists air infiltration and water intrusion, yet is engineered to readily allow moisture vapor to diffuse through the sheet, helping prevent mold and mildew buildup and wood rot. The fibrous structure is engineered with microscopic pores which readily allow moisture vapor to evaporate but are so small bulk water and air cannot penetrate. Siding, whether vinyl, wood, stucco, brick, or composite, does not completely prevent air and water penetration. House wrap is designed as a secondary defense to help manage a building’s wall systems.

R-Value ratings for insulation are only maintained as long as the air within the insulation stays still and dry. The Department of Energy estimates nearly 40% of a building’s energy loss is the result of air infiltration caused by wind driven pressures from the outside. The opposing forces of pressure between inside and outside walls cause heat and air conditioning to be virtually sucked from a building– through walls, ceilings, sill plates, sheathing joints, top plates, electrical outlets and every inch of the estimated half-mile of cracks in newly constructed buildings. As air infiltrates, it causes changes in temperature which require heaters or air conditioners to work harder. Constant temperature fluctuations also reduce comfort levels. Occupants feel too cold or too warm. Reducing air infiltration increases a building’s comfort factor.

Insulation can help increase the R-value, but it is only marginally effective in reducing air infiltration. When air infiltrates, the R-value itself can be reduced up to 60%. Adding thicker insulation won’t solve the problem. Stopping air from getting in, will.

Properly applied, house wrap helps reduce air infiltration, preserving R-values, conserving energy, reducing heating costs and creating a more comfortable interior.

The tighter the building, the more comfortable and efficient. Unfortunately, the tighter a home, the more susceptible to moisture problems which can cause mold, mildew and rot. So all systems need to be in balance–designed to manage water and moisture effectively.

There are two main ways water and moisture get into wall systems:

Bulk water intrusion from the exterior (rain and snow) can enter the wall and, if not allowed to dry in a reasonable amount of time, can raise the moisture content of the wood above 30% and cause rotting or mold and mildew.

Air transported moisture occurs when air leaks from the warm side of the wall to the cool side. Warm air will hold higher amounts of moisture than cold air. As warm air travels through a wall heading to the cold side, it will begin to cool and be forced to release moisture. This is called the dew point where condensation will occur. When there is a significant temperature drop across the wall, the dew point will occur somewhere within the wall. In the winter months the point of condensation is usually on the inside surface of the exterior sheathing. Moisture carried by air flow through the wall is deposited at the back side of the sheathing and accumulates. In hot and humid climates where air flow is traveling from the outside to the inside, warm moist air from the outside will be cooled on the way to the air conditioned inside, releasing moisture within the wall cavity. House wrap is a breathable membrane with microscopic pores which allow the moisture vapor to dissipate, helping to dry out a wall system to avoid damage.

Moisture Vapor Transmission Rate or perm rate of a material determines the ability for water vapor to diffuse or evaporate through the wall. The higher the perm rate, the more “breathable” the material is and the easier it is for water vapor to pass through. Materials with Perms below 1 are considered vapor retarders since the rate of moisture vapor flow through a 1 Perm material is so low there is essentially no flow. House wraps have Perm rates in the area of at least 58 Perms which is very open to allow moisture vapor to flow through.

What house wrap is not, is a vapor barrier or an insulation. I’ve seen instances where people have applied house wrap directly between roof purlins and roof steel, in an effort to control condensation. House wrap is quite permeable; any warm moist air which would rise to it will pass through to the underside of the roof steel and condense.

House wrap is great…if used for what it was intended for…a secondary defense against the weather.