Tag Archives: add on

Condensation Control, Mother/Daughter Addition, and Vapor Barrier for Roof

Today the Pole Barn Guru answers readers questions about condensation control in a small garage with a gravel floor, the possibility of adding a “mother-daughter” unit to her house, and “ribbed vapor barrier” for a shed roof.

DEAR POLE BARN GURU: Recently purchased a metal garage kit, 24X26. No insulation. Two garaged doors. Gravel floor with plastic under grave. I am getting condensation on some days, that makes my cars, etc have like a dew on them.

My rib looks to be 1” and 7” between ribs. How do you install a wall vent with the ribs? JODY in ALTON

Machine ShopDEAR JODY: First step is to take care of your source. Pour a concrete slab on grade with a well sealed 10-15mil vapor barrier underneath. As you have no thermal break between your warm moist air inside building and roof steel, have two inches of closed cell spray foam insulation applied to underside of roofing. You would be better served to vent eaves and ridge, than just gable vents. If gable vents are your choice, look for vinyl vents with a snap ring as they can be installed on ribbed steel siding.

Using inward vent base edges as a guide, mark area to be cut on endwall steel INSIDE, make hole cut square with steel sheet (vertical cut lines parallel to steel ribs). Cut hole with appropriate tools.
Push vent base through hole in steel from inside.
Note word “TOP” on base when positioning. Vents installed with top side in any direction other than up will allow water to leak into building.
While holding vent base in place, snap face into base from steel exterior by pressing firmly (this takes two people).

 

DEAR POLE BARN GURU: I’m interested in building an attached mother/daughter addition to my home. Do you have plans for that? Approximately 600-700sq ft. NANCY in MONROE TOWNSHIP

Floor PlanDEAR NANCY: Thank you for your interest in a new Hansen Pole Building. Every building we provide is custom designed to best meet the wants, needs and budget of our clients. We offer a floor plan design service for folks just like you: http://www.hansenpolebuildings.com/post-frame-floor-plans/?fbclid=IwAR2ta5IFSxrltv5eAyBVmg-JUsoPfy9hbWtP86svOTPfG1q5pGmfhA7yd5Q 

 

DEAR POLE BARN GURU: We are having a 50×30 all metal building. We were advised to get ribbed vapor barrier for roof. We have searched everywhere. Is it called something else? SHANNON in OLEAN

DEAR SHANNON: We are also not familiar with any product known as a “ribbed vapor barrier”. We would normally recommend use of roof steel with an ICC factory attached (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/). If this is not an option (or if you are using closed cell spray foam directly to underside of roof steel), next choice would be a radiant reflective barrier – look for six foot wide rolls with an adhesive pull strip attached for ease of installation.

 

A Post Frame Addition, California Muster, and Ventilation

Today the Pole Barn Guru answers questions regarding a post frame addition, passing the “muster” of California’s building codes, and ventilation of attic space with spray foam.

DEAR POLE BARN GURU: Hi. We are wanting to attach a monitor style barn to an existing stick build for additional residential use. Is this tie-in possible? Thank you! TOM in KIRTLAND

DEAR TOM: It is very possible and will quite probably provide some real advantages, besides just affordability. Post frame buildings can be any variety of sidings, so it should be able to be structurally designed to tie pretty much up to any type of exiting building – provided existing building is structurally sound.

In order to do this right you have only a couple of choices – you can spend a lot of money on an architect and/or engineer who physically comes to your site (could be as high as 20% of project’s finished costs). Or you can provide lots of information to us on what we are attaching to, as well as conveying your expectations. We will do anything reasonable to assist you in not making a mistake you will regret always. If I thought anyone else could not just actually do it but also do it better than us, with you being able to construct yourself, I would in all honesty let you know.

Please dial 1(866)200-9657 and speak with a Hansen Pole Buildings’ Designer who can assist you to success.

 

DEAR POLE BARN GURU: Hi, Do you have any residential structures that have recently passed muster in southern California?

FYI I have a lot in Malibu but little $. I am wondering if I – and usually one helper – could construct a fire resistant home in this picky building code state.

Thanks, DAN in LOS ANGELES

DEAR DAN: We’ve been providing post frame building kits in Southern California areas of Very High Fire Hazard Severity Zones as well as Wildland-Urban Interface Fire Areas for years. Is does take a certain amount of patience, as plans almost always get kicked back at least once (relax – it is just a part of this process). Using steel roofing and siding, unvented steel soffits and wrapping any wood normally exposed with steel trims expedites approvals. If your property is located in a HOA (https://www.hansenpolebuildings.com/2012/11/homeowners-association/) be certain to talk with them sooner, rather than later.

As far as you and a helper – as long as you can and will read instructions and look at our third-party engineer’s highly detailed plans you should experience no real challenges. And, if you get stuck, we provide unlimited Technical Support at no extra charge.

A Hansen Pole Buildings’ Designer will be reaching out to you for more in depth discussions.

 

DEAR POLE BARN GURU: We bought a house kit from you all and have been very pleased. We had the roof deck, exterior walls and exterior walls of the crawl space spray foam insulated. They have essentially sealed the house. Will the lack of attic ventilation be an issue? HOLLY in TAYLORSVILLE

DEAR HOLLY: Thank you for your kind words, we would enjoy seeing any digital photos or video of your building during construction as well as completed.

If you spray foamed roof deck and have a dead attic space due to a flat level ceiling (we provided ceiling loaded trusses as well as ceiling joists) then you could experience condensation issues and potentially mold and/or mildew in attic, especially if attic is not made part of conditioned space (heated and/or cooled) with living area. If flat ceiling has also been insulated look out for trouble (keep a close eye on situation by doing visual attic inspections), as attic space could become quite a bit cooler than area below ceiling. Your spray foam contractor should have been talking with you about this prior to doing his or her application.

 

Pole Sizes, Adding On a Shed Roof, and Ridge Vents

DEAR POLE BARN GURU: We live in Pacific county in Washington state and wondering what size of truss pole we would be looking at needing for a 60 ft truss. We are in a wind exposure “C” and trusses will be on 12′ centers. The building we are planning will be 60’w x 48’d with 15′ eve height. Any help will be appreciated.

Thank you,CRAIG in RAYMOND

Concrete slab in a pole barnDEAR CRAIG: There are a plethora of factors which will go into determination of what size columns will work for your or anyone else’s new post frame
building. These include (but are not limited to):

Soil bearing capacity
Embedment depth
If columns will be tied into a concrete slab
Spacing of wall girts
Is building fully enclosed, partially enclosed or a roof only
Slope of roof
If building has a ceiling
Roofing material

When you order your new post frame building package, all of these variables will be factored into the design of not only the columns, but all of the components and your building plans as well as the supporting calculations will be sealed by the engineer of record.

 

DEAR POLE BARN GURU: I want to attach a shed roof along the side of my 40 foot pole barn. The span is 12 feet and I plan on the outside of the roof being on 10 ft. high 4×4’s and raising it to a height of 12 ft. on the pole barn. There are 5 6×6’s to line up the 4×4’s to. I was wondering the most cost effective way to attach the metal for the shed roof. I plan on enclosing the sides when funds permit, but for now help with what type of construction, be it wooden trusses or just 2×6 or 2×8 rafters.

Thanks in advance for all your assistance. BEN in TONEY

DEAR BEN: The most cost effective method (as well as structurally correct) will be to discuss your project with a Hansen Pole Buildings’ Designer. With your investment in a new post frame building will come plans which correctly size and locate all members as well as detailing all of the connections.

With this said….

The 4×4 columns you propose using will not be adequate to carry even the most minimal of loads which will be imposed by Code.

Your shed will be designed with a single rafter on each end, and rafters on each side of the interior columns. Depending upon the load conditions at your site, expect to see 2×10 or more probably 2×12 rafters. Purlins on edge will be joist hung between the rafters and the roof steel will attach to the purlins with screws.

DEAR POLE BARN GURU: I paid for continuous roof venting and I got plain 14 in ridge cap can you look in to this? JOE in CLEARWATER

vented-closure-strip

 

DEAR JOE: The steel ridge cap itself does not change for a vented ridge – the foam closure strips beneath the ridge cap provide the ventilation. According to our records, you were shipped the correct vented closures. Please advise if by some chance you did not receive them.