Tag Archives: foundation insulation

Pier Insulation, Hold Up Distances, and Site Prep

This week the Pole Barn Guru answers reader questions about insulating around outside of post piers, the hold-up distance of any non-treated lumber or wall sheathing, and if laying gravel prior to drilling and setting columns would be best order of building.

DEAR POLE BARN GURU: Kind of a 2 parter. I am trenching 4′ straight down around the perimeter (in between posts, just inside the splash plank) of my post frame home. Should I also do the porch on the front of the house? Also I was told I should insulate around the outside of the post piers as well to prevent frost heave. Is this necessary? If so how would I do that if my collard are already poured? DYLAN in GLENWOOD

DEAR DYLAN: Your easiest design solution is to place rigid insulation boards down 2′, then out horizontally (most Building Departments accept 2′ out). This places all of your insulation above tops of concrete collars. This guide should prove helpful (keep in mind, it is for traditional stick built, but concrete has no magical frost preventive properties, so replace “concrete” with compactable fill): https://www.huduser.gov/publications/pdf/fpsfguide.pdf Your porch is best insulated, not only around perimeter, but also under slab itself.


DEAR POLE BARN GURU: Hey I see you post a lot on the pole building pages. I have a question about vinyl siding on a pole building and how to keep the OSB water proof. Which a traditional pole building you have your metal siding attaching to your skirt board, but with vinyl siding you have OSB nailed to your skirt board and then tyvek then your siding. How do you keep the OSB board from wicking water up from the ground when you back fill on the outside of the building? Is there a proper way to keep that water tight? STEVEN in CENTREVILLE

DEAR STEVEN: By Code – any non-treated lumber or sheathing must be kept at least six inches above grade. When we have OSB or plywood sheathing, or T1-11 siding, we use a 2×10 pressure treated splash plank, so there is still 3-1/4″ of splash plank to nail to when sheathing is held up 6″.


DEAR POLE BARN GURU: Is it ok to put in the gravel leveled and compacted before the builder starts building the post type garage This is what they like, not sure why. Thanks. DAVID in SHEPHERDSVILLE

DEAR DAVID: It is going to be far easier (and less expensive) to properly grade your site and compact fill before your building begins, than trying to do it afterwards. Working equipment around posts and walls is going to be time consuming and can result in structural damage, if not done carefully.

Endwall Overhangs, Foundation Insulation, and Sloping Ground

This Wednesday the Pole Barn Guru answers reader questions about setting trusses on a Hansen Building with endwall overhangs, a solution for an insulation question, and the possibility of building on steep sloping ground with some exposed columns.

DEAR POLE BARN GURU: Are all trusses set at the same height are the end trusses lower so the purlins hang over the end truss by 2 feet? TROY in SCAPPOOSE

DEAR TROY: Thank you for your investment into a new Hansen Pole Building.

For quickest answers to technical support questions, please refer to Page 2 of your Construction Manual.

Our buildings are designed to maximize interior clear height, so roof purlins are joist hung into sides of interior truss top chords (Detail 5/S-3 of your engineer sealed plans). In order to support endwall overhangs, roof purlins go across end trusses (detail 9/S-4). With a 5/12 roof slope and 2×8 roof purlins, this requires lowering end trusses by 7-5/8″ as shown on Sheet S-4 of plans.

You will want to review and familiarize yourself with Construction Manual Chapter 55.


DEAR POLE BARN GURU: Hi Mike! I’ve been looking for a good answer to a question that I have, your profile name suggests you might just be the guy to ask! I very much would like to put a upcoming post frame building project on a 6ft frost protected foundation, 4 ft below, and 2 foot above grade. The building will be heated and cooled, and I just have not come across the best detail on how to insulate, protect the exterior insulation, and flash between the exterior steel and the foundation insulation. What is the best way to go about this to balance R-value, appearance, and durability that come with that 2ft of above grade foundation wall. Thank you for your time! CODY in WISCONSIN

DEAR CODY: In my humble opinion, foundation walls for post frame buildings defeat much of the cost savings with little or no added benefit. I will now step off my soap box….

You can achieve same (if not better) results by adding insulation board to inside of your wall. It also takes away protection and flashing challenges. Look at using Rockwool Comfortboard 80.


DEAR POLE BARN GURU: Can any of your buildings be built where the back half of the building is suspended on poles…..because the ground slopes downhill? What about zoning? Do you check with my county to find out whether or not I can have a building? DAVID in WESTMINSTER

DEAR DAVID: Yes, some or all of your new Hansen Pole Building can be suspended on poles (basically a partial ‘stilt’ house). https://www.hansenpolebuildings.com/2017/09/stilt-houses/

While we do not check with your county to find out whether or not you can have a building, it is a very pain free process for you to confirm: https://www.hansenpolebuildings.com/2020/01/your-barndominiums-planning-department/


Tyvek Weather Barrier, Overhead Door Sizes, and Slab Insulation

This week the Pole Barn Guru answers questions about use of Tyvek weather barrier, best size for overhead garage doors, and insulation for a slab.

DEAR POLE BARN GURU: Hi, I was thinking of putting up a metal clad pole building and insulating it with R28 batt. Wondering your thoughts on adding Tyvek to the outside to help protect against the weather? Not sure if the cost is worth it? Most of the builders around here don’t recommend it. DOUG in REGINA

DEAR DOUG: Your local builders probably do not recommend use of a Weather Resistant Barrier (WRB) in walls because they fear increasing of prices on their quotes – they are selling low price, rather than best value for their clients.

If you are not going to flash and batt (https://www.hansenpolebuildings.com/2020/01/flash-and-batt-insulating-barndominium-walls/) your walls, then use of a WRB is an excellent choice as it allows any moisture from within your insulation cavity to escape outward. Use unfaced batts and then cover interior of your walls with well-sealed 6mil clear visqueen prior to an interior finish.


DEAR POLE BARN GURU: I’m fixin to build a barn, 40×40 12’ walls with 3 overhead doors. Going to put a lift in it. Have any suggestions on door size and spacing. I live in all sand so for my post I’m buying sono tubes so it won’t cave in on me. What size sono tubes? Planning on 6” concrete floor with thickened slab where hoist goes. Anything I’m forgetting? ANDREW

DEAR ANDREW: You actually probably need at least a 12′ ceiling for a lift. I always recommend at least 3′ from a wall and 3′ in between (it avoids door dings). With a 40′ wall – this will not quite work out (in my ideal world). I like 10′ wide doors, as they keep mirrors on much better. I also like 8′ tall doors, hardly any more than 7′ and gives room for racks, most lifts, etc.

In summary I would do (2) 10′ x 8′ (1) 10’x10′ (might as well take advantage of the ceiling height. Go 3′ from corners and 2′ in between.

Our third-party engineer will determine depth and diameter of sonotubes and they will be called out on your sealed plans.


DEAR POLE BARN GURU: Hi Mike, I am working on building a post frame home in Eastern Oregon. Looking for ideas on slab insulation detail at perimeter edge. The home will not have radiant floor heat.

I am having trouble deciding on how to insulate the perimeter slab. Oregon requires minimum R-15 for slab edge insulation. Ideally I would prefer to see concrete at exterior perimeter vs treated grade board that’s visible, however the treated grade board seems to be most cost effective in design. TRENT in WALLA WALLA

DEAR TRENT: I had just recently done this for one of our clients and we will be adding it to our construction manual. This hides your splash plank (grade board). Thicknesses and dimensions can be found here (https://www.huduser.gov/publications/pdf/fpsfguide.pdf Table 2, Page 6). Even though you are not using radiant heat, I would run Pex-Al-Pex tubes in my floor and do under slab insulation. It is a huge selling point and gives you flexibility to add radiant floor heat easily at a later date.