Tag Archives: Post Frame Home

Raised Floors in Post Frame Homes

Raised Floors Are an Opportunity for Post Frame Homes

Three months after Hurricane Harvey churned through Texas, dumping 51 inches of rain and damaging an estimated 150,000 homes, the state’s most populous county took a bureaucratic step which has huge implications for how it will deal with the risk of future flooding.

On December 5, Harris County, which surrounds the City of Houston, approved an overhaul of its flood rules expanding them from 100-year floodplains—which have a one percent change of flooding in a given year—to 500-year floodplains. The new rules (which don’t apply inside Houston city limits) will compel people building houses in some areas to elevate them up to eight feet higher than before.

“We had 30,000 houses that flooded” from Harvey, said county engineer John Blount, who put forward the rule changes. Before the floodwaters even subsided, hundreds of county employees fanned out to survey the damage. “We went to every one of those houses and figured out how much water got in them, and then we did a statistical analysis,” Blount said.
The data was geocoded, factoring in location and neighborhood conditions, and one result was the increased elevation rule. (The county is also buying out 200 of the most vulnerable homes and hopes to buy out thousands more, but those represent a small fraction of the homes inside the floodplain.)

Harris County’s new rules are the most stringent flood-related development restrictions anywhere in the United States, according to Blount. If a future Harvey-sized deluge comes, almost all the homes in the area will be safe, he said: “Had that same event happened, at the same location but [with houses] built to the new standard, 95 percent or more would not have flooded.”

For a structure, standing water is a fearsome enemy. Even a small amount of flooding in a home can exile its inhabitants for weeks and require costly repairs. After Harvey, tens of thousands of evacuees lived in hotels or with friends as workers in their homes tore out drywall to prevent the spread of mold, which can sicken residents. And more Harveys are coming: As Robinson Meyer reported, a new MIT study concludes Harvey-scale flooding in Texas is six times as likely now as it was in the late 20th century, and will only get more likely as this century wears on.

More than a million people live in the 100- and 500-year flood zones across the Houston area, and hundreds of thousands more do in other U.S. cities, including Miami and New York. Harris County’s move conforms with the advice of building engineers, climate experts, and the insurance industry. If you live in an area which is prone to flooding—or will be soon—getting off the ground is the best way to avoid recurring, expensive, and heart-rending damage to your house.

“There’s no real substitute for elevation. That’s your best bet,” said Tim Reinhold, senior vice president and chief engineer of the Insurance Institute for Business and Home Safety (IBHS), a research organization based in Tampa and funded by insurers.
Houses don’t have an engineered safety margin for avoiding flooding the way they do for wind resistance, Reinhold points out; even a few inches of water can be devastating. His advice: “Build that margin in by going higher.” The IBHS recommends elevating houses three or more feet above the 100-year floodplain.

Yet three feet is nowhere near standard. The City of Houston requires one foot of elevation above the 100-year floodplain. Many jurisdictions in Texas and other states require none. What seems like a simple, obvious safeguard raises tricky questions: How high is high enough? Who has to pay for it? And at what point does it no longer make sense to build in a place at all?
Nationwide, according to Census data, 59 percent of new single-family homes are “slab-on-grade,” as it’s known in the construction industry. The technique is pretty much what it sounds like: Concrete is poured into a mold set shallowly into the ground, forming a slab several inches thick. Because a ground freeze can crack the slab, the method is mainly used in warmer climates. It’s straightforward and cheap. But it results in a house with a low elevation, which is obviously not ideal in a flood zone. “I don’t understand why you would ever build a house on a slab on grade that could be in a flood-prone area,” Barcik said.
Building a house with a raised foundation isn’t cheap. “If you’re starting with a home that’s slab-on-grade right now, and want to raise it by using fill, it could be $13,000 to $14,000 to do that just one foot,” said Gary Ehrlich, the director of construction codes and standards for the National Association of Home Builders.

Mike the Pole Barn Guru comments:
The fill method—trucking in soil and resting the slab on top of it—is cheaper than the pier-and-beam or stem-wall options. But it’s not adequate for raising a house’s height by several feet. The eight-foot-elevated homes now required in parts of Harris County would carry significant added costs, which builders would pass on to homebuyers.

However, elevating a post frame home, even as much as eight feet, is a negligible investment compared to the costs of stick frame construction. Considering constructing a new home? If so, look towards post frame construction as an affordable design solution.

How to Keep the Water Out of a Pole Building

How to Keep the Water Out of a Pole Barn

The post frame (pole barn) building has moved from the farm to suburbia. With the transition in building uses, having water flowing into a post frame business or residence is far less than desirable.

Dear Pole Barn Guru: My parents lived in a pole barn “lodge”. When there was a lot of snow and it blew against the building, as it melted water would get in under the walls. Grading was away from the building. Was the slab not poured high enough? Is there a way to seal bottom during construction that maybe wasn’t done properly? We want to have a pole barn home built, but need to educate ourselves on these details to make sure the work is done properly. Carolyn in Cleveland

Mike the Pole Barn Guru answers:

My bride and I happen to live in a post frame home in South Dakota, where in both snows and blows. Our building also has a huge footprint, being 84 feet wide and 60 feet deep. A six inch snowfall easily results in a berm along each side several feet in height.

For our slab on grade building, we made sure to have some serious slope away from all four sides of the structure.

From the 2015 IBC (International Building Code):

“1804.4 Site grading.

The ground immediately adjacent to the foundation shall be sloped away from the building at a slope of not less than one unit vertical in 20 units horizontal (5-percent slope) for a minimum distance of 10 feet measured perpendicular to the face of the wall. If physical obstructions or lot lines prohibit 10 feet of horizontal distance, a 5-percent slope shall be provided to an approved alternative method of diverting water away from the foundation. Swales used for this purpose shall be sloped a minimum of 2 percent where located within 10 feet of the building foundation. Impervious surfaces within 10 feet of the building foundation shall be sloped a minimum of 2 percent away from the building.

Exception: Where climactic or soil conditions warrant, the slope of the ground away from the building foundation shall be permitted to be reduced to not less than one unit vertical in 48 units horizontal (2-percent slope).”

Regardless of siding type, a high quality and well-sealed building wrap (https://www.hansenpolebuildings.com/2012/11/house-wrap/) should be placed under the siding with the bottom edge at the bottom of the siding.

With steel siding, inside closures (https://www.hansenpolebuildings.com/2015/12/the-lowly-inside-closure/) can be placed between the building wrap and the steel siding to fill the voids created by the high ribs of the steel siding.

For residential purposes, I would strongly encourage the use of a raised wood floor over a crawl space as a living surface. It will add to comfort and should pretty well eliminate any potential for water infiltration around the base of the living area.


Looking for a Contractor to Build a Post Frame Home

More and more consumers are seeing the practicality, unique architectural and energy savings advantages as well as cost savings from a post frame home. This includes loyal reader Brian who writes:

Engineer sealed pole barnHello, my wife and I are considering building a post frame home. We contacted a designer who actually had plans for a home that is close to what we were wanting. He suggested it may be difficult to find a builder that would be comfortable building a pole barn home – so that is why I am contacting several builders to develop a list that could be considered in the future if we move in this direction.

Please find the attached plans he provided as a reference and let me know if this is a project you would be willing to tackle. Although we have not bought land we are currently looking in Warren and Clinton counties in Ohio.

Dear Brian: Thank you very much for your interest in a new Hansen Pole Building. We design and provide building plans, installation instructions and materials for totally custom post frame buildings. Your proposed plan (as would be any other plan) is totally doable as a post frame (pole barn) home.

What we do not do is build. Our buildings are designed for the average do-it-yourselfer to successfully construct their own beautiful building, which is why the majority of our clients do their own work. Those who construct themselves, end up with a far better finished result than what you would get from any builder.

In the event you do hire a builder (technically an erector), any builder who can and will read and follow the plans and instructions should prove capable of doing a satisfactory job. Given your geographic location, just a caution based upon experience – there are members of a well know religious group which construct many post frame buildings in your area of the country. While their prices sound too good to be true, it is our experience they do not always build to the provided plans or follow instructions. Again, just a caution. Otherwise a capable erector should be able to construct the building shell for about 50% of what your investment in the materials is.

About Hansen BuildingsI am not normally a fan of “canned” plans for any type of construction, as they are rarely going to meet with the true needs of the client. My best advice is always going to be to determine the spaces needed, determine how large each of those spaces need to be. A good way to find the right size of rooms is to take a note pad, writing tool, and a tape measure and start visiting open houses and home tours.

Once room needs and sizes have been determined, starting putting the pieces of the jigsaw puzzle together – place rooms where they are most efficiently grouped for ease of access and use. This may take some adjustments of individual room dimensions, however the resultant will be the most effective. Now, and only now, should you put the “box” around the contents!



Consider Post Frame for New Home!

DEAR POLE BARN GURU: Good morning. My name is Thomas and I am with xxxxxx; we manufacture metal roofing and siding and based out of Tennessee. I wanted to ask you a few questions to gain some information. First, my wife and I are starting to look at metal building for our new home, is this something your company is licensed to do in the state of Tennessee; second, I also would like to know if you manufacture your own metal roofing and siding, or if it is purchased from another company. Hope you had a great Christmas and I look forward to hearing back from you. THOMAS in MURFREESBORO

DEAR THOMAS: Thank you for your inquiry. Hansen Pole Buildings provides engineered post frame buildings in all 50 states, including Tennessee. Post frame (pole) building homes have become quite popular in the past few years and chances are excellent we can provide a customized building shell which will ideally meet with your needs and budget. We outsource our metal roofing and siding and we can provide the building sans roofing and siding in the event you should wish to provide your own.

DEAR POLE BARN GURU: I have submitted a request for a quote on our residence but I’ve needed to make a few modifications. How important is post spacing on a residential post frame building? The residence I’m designing is based on nominal 8′ post spacing but with the interior design I have, a couple of the posts interfere with window/door placement. I’ve been assuming that as long as opposite side posts are aligned so that the trusses are supported, the post position can be varied somewhat. On our design, I’ve assumed nominal 8′ post spacing but actual spacing winds up being as close as 7′ and as wide as 10′ 6″. Can irregular post spacing be accommodated or do I need to modify our interior design? Thanks LONNIE in COLORADO SPRINGS

DEAR LONNIE: Your assumption, “as long as opposite side posts are aligned so that the trusses are supported, the post position can be varied somewhat” is absolutely correct. In most circumstancing having the sidewall columns spaced at 12 foot on center is your most economical, so anything at this spacing or less should not be an issue from an engineering and design standpoint. When you arrive at an ideal spacing, please make sure it is listed on any quotes and invoices, otherwise there is always the possibility of columns being reorganized to the most cost effective combination.

DEAR POLE BARN GURU: Is there a recommended distance from the peak of a roof that the top purlin is installed, and why? WILL in NEWPORT

DEAR WILL: Yes there is a recommended distance. Here is the applicable excerpt from the Hansen Pole Buildings’ Construction Manual:

With standard steel ridge caps, the ridge purlin “uphill” side can be no closer to peak than five inches. This may result in space between ridge purlin and next purlin “downhill” being decreased. Ridge purlins can be further from truss peak than the minimum distances, without negatively affecting building. Roof ridge caps attach to roof steel with metal-to-metal screws, not to ridge purlins, so ridge purlins need not align with future ridge cap fastener locations.

If ridge purlins are “uphill” further than this, roof steel may not have an adequate overhang at eave and challenging situations will result!”