# Building Height, Building on Existing Foundation, and Spray Foam

Today the Pole Barn Guru answers questions about calculating the height of a building, Building on and existing foundation, and Spray Foam Insulation.

DEAR POLE BARN GURU: I’m looking for over all height of a building with a 14’ eave?
Thanks. DOUG in PILOT ROCK

DEAR DOUG: The overall height determination starts with a clear understanding of how eave height is to be measured: https://www.hansenpolebuildings.com/2015/02/eave-height-2/.

With this in mind, the rise of the roof can be calculated by multiplying the distance from sidewall building line to the center of the building, in feet and multiplying this by the roof slope. Here is an example for a 36 foot width gabled roof with a 4/12 roof slope:  36′ X 1/2 (half the building width) X 4″ / 12″ = 6 feet. Adding this to the eave height gives an overall height of 20 feet, in this particular example.

DEAR POLE BARN GURU: Can they be built on a poured basement wall from a previous home? PAT in GREENEVILLE

DEAR PAT: As long as the concrete is structurally sound you should be able to utilize dry set column bases (ones designed specifically for post frame construction) to mount columns to the top of the foundation.

DEAR POLE BARN GURU: I have an existing Hansen pole barn 24×24 with a 9ft eave height and full length ridge vent, it has reflective roll insulation between the roof panels and the purlins. How can I further insulate it from Florida heat? I insulated the walls with rigid insulation. Can I add insulation under the existing reflective insulation at the roof? STEVE in ROSELAND

DEAR STEVE: I’d be contacting local installers of closed cell spray foam insulation. You will get close to R-7 per inch of foam (again, must be closed cell) and do not have the ventilation issues posed by using batt insulation between purlins. You will need to block off the eave and ridge vents for this to be an effective solution.

# Setting posts: Postsetaphobia

Setting Pole Barn Posts

I recently spoke with a prospective client in California. This particular gentleman is an electrical contractor, and fancies himself as being fairly handy. He is considering doing the construction of his new pole building kit himself, however was terrified by the prospect of having to set the building columns.

Being honest, we all have our fears and phobias. One of the most interesting ones I encounter frequently with clients (such as our friend above) is “postsetaphobia”, or fear of setting posts. This particular phobia is defined as, “the fear of being able to properly set posts for a pole building”.

Fear is False Evidence Appearing Real.

99% of all fear is not justified and is not “real” unless one focuses on it and attracts it.

Examining the realities of the situation….most pole building foundation systems are based upon rectangular or square sawn pressure treated timbers, embedded into holes augered into the ground. Sounds scary when defined like this, isn’t it?

Setting posts is really very easy!

These augered holes are going to range from an 18 inch diameter on a very small building, to 24, 30 or even 36 inch diameters on a large structure. Assuming a very small building, the columns will probably be 4×6. Now a 4×6 actually measures 3-1/2” x 5-1/2” (topic for a future blog posting), or 6-1/2 inches across the diagonal. Even with the least hole diameter of 18 inches, this leaves almost a foot of “slop” to play with!

So, what is the worst thing which can happen so far? A hole is drilled a few inches off center and the very small “peg” gets shifted in a very large round hole. By moving the posts back and forth at the top of the hole, the columns can be shifted as needed to end up in a straight line.

How hard is it to obtain “plumb” when setting posts?

But, “what if I cannot get them plumb” (straight up and down)? By adjusting the braces, which temporarily support the columns prior to concrete being poured, the tops of the poles can be moved to being fairly plumb quite easily. While the ideal scenario is to have the tops of the columns leaning slightly outward, pole buildings are amazingly forgiving and the tops of the poles can be adjusted laterally by even several inches later in the construction process.

Over the course of 30 years most of the pole buildings I’ve sold have been constructed by homeowners with no building experience whatsoever.  I have yet to have someone who has voiced this setting posts concern to call me later and say “It was a nightmare”.  Instead, I’ve had countless folks tell me, “Wow, it really wasn’t so bad after all”.  Like many fears, this is one in which the anticipation of the event, is far worse than the real thing.

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