Tag Archives: rebar

Rebar for Post Frame Concrete Slabs on Grade

Building with concrete involves many steps to achieve best results, including grading, forming, placing and finishing. One crucial step is placing reinforcing bars (rebar) correctly.

An engineer should do technical design work and provide specific information regarding sizes, configuration and placement of rebar. Slabs-on-grade for post frame buildings do not usually carry building loads, these are usually carried from roof and walls, through building columns to ground. This makes for far less complicated applications, unlike PEMBs (Pre-engineered Metal Buildings) or “weld ups” either being far more convoluted and beyond the skill level of all but experienced professionals.

rebarFor slab reinforcement, necessary rebar can usually be obtained from a big box store (like The Home Depot®) or your local building supply. Should your specific application be more involved, it may behoove having a fabricator supply rebar. A fabrication supplier can review your building’s engineered drawings and produce a shop drawing with details and identifying tags for each type of rebar to be used in your building. For simpler projects, your building plans should provide spacing requirements and bar sizes. Use these documents to determine where and what rebar is needed in individual locations.

Most often rebar is tied with annealed steel wire, either purchased in four pound bulk rolls, or if using a bag tie spinner, in bundles of pre-cut wire pieces with loops formed on both ends. Bulk rolls are easier for novices to use, however are slightly more expensive.

Prior to placing any rebar, grade and properly compact the ground after all grading and any utility rough-ins are completed. Make sure all compaction testing has been completed and you have your geotechnical engineer’s sealed report in hand before moving forward. Any termite pre-treated should be completed, as well as a moisture barrier installed.

As post frame construction places columns and splash planks prior to pouring your slab, this gives you ready made forms for your slab perimeter.

Determine the size of bars to be used in each direction and mark several of them with layout measurements in each direction (front-to-back and side-to-side). Bars can be marked with a soapstone marker, a paint pen, lumber crayon or even spray paint.

This will be an ordinary slab mat concrete, the force interacting with rebar during placement is minimal. As mat movement is unlikely, a simple single twist of wire around each rebar intersection, twisted together tightly will be adequate. This tie can be done easily with a pair of nine inch lineman’s pliers.

To use your pliers to tie these efficiently, pull feeding end from wire reel with your non-dominant hand (for sake of this article, we will call this your left hand, with pardons to lefties). Grip wire end with pliers in your right hand. Push wire behind (under) rebar at an intersection. Angle end towards where you will be grabbing it, reach from this side, grip it again with pliers, pull towards next location pulling enough slack to complete tie. Hold resistance on wire with left hand, so wire bends snugly against bar being wrapped, at each stage. Release wire so pliers can be used to grip it. Pull end around bar and twist two ends together, pulling wire with pliers so tie is tight.

Once mat is assembled it must be held in place so concrete will cover it completely. Rebar chairs or concrete brick are often used for this. Place these positioners close enough together so rebar will not sag enough to reduce desired coverage of concrete – usually about 1/3rd distance from bottom of slab.

Watch rebar configuration as concrete is placed. If shifting occurs, support rebar with a shovel or alter direction of concrete flow so force is applied in the opposite direction.

Use caution when working around exposed rebar. Construction workers have suffered serious injuries or been killed when falling on projecting rebar.

Uplift Plate

Uplift Plate™
I realize I got you readers happily involved in reading a series of articles however I need to break it up slightly.

In delivering “The Ultimate Post Frame Building Experience”™ Hansen Pole Buildings perpetually searches for new materials and methods to maintain our post frame kit packages as best possible value for your investment.

An upgrade in recent years has been, for all roof supporting exterior building columns, inclusion of an Uplift Plate™.

According to vendor’s information, Uplift Plate™ is a revolutionary new product saving Do-It-Yourselfers and post-frame builders time and money, while exceeding uplift requirements; it’s a new way to anchor post fame buildings. This state-of-the-art design securely anchors posts to concrete without requiring time-consuming drilling. These inexpensive plates are field applied with just a framing hammer, eliminating extra tools and time associated with rebar or other uplift techniques. Simply hammer plates onto columns and it’s ready to set in ground for concrete pour.

UNDERSTANDING HOW IT WORKS In order to anchor a post properly you need to make sure column and concrete are fused for life. Older techniques involve drilling holes though column and pounding in a piece of rebar. Or nailing a block or blocks of wood onto column. Either one becomes only as strong as materials used to join it.

 

Why Choose Uplift Plate™ Over Rebar?
Hot Dipped Galvanized Coated
or Regular Version
Easy to Install
Low Cost, Great Value
3 Times Stronger Than Rebar
Lightweight, Easy to Handle
Decay Resistant
Easily Worksite Application
Protects Center Post From Climactic Elements
Creates a Strong Bond
3 TIMES STRONGER? STUDY PROVES IT!

Using Truss Plate Technology Uplift Plate™ creates a stronger better alternative. Uplift Plate™ provides an adaption of this technology, simplifying processes while strengthening concrete to column bonds. Holding power increases by three times when using Uplift Plate™ compared to two ½ inch pieces of rebar.

A certified professional engineer performed a study utilizing mechanical tests comparing strength and durability of both Rebar and Up-Lift Plates encased in concrete. This study concluded Up-Lift™ Plate was three times stronger than rebar with its anchoring capabilities.

A new Hot Dipped Galvanized coated version meets International Building Code approval for Underground Application.

Foundations

Foundations – Post Frame Keeps It Simple

Post frame (pole building) construction affords a plethora of savings for a new building owner, chief amongst these are foundation simplicity. I’ve previously expounded upon foundation savings in post frame construction as compared to stick frame buildings: https://www.hansenpolebuildings.com/2011/10/buildings-why-not-stick-frame-construction/.

Today I will add some graphics to reinforce (pun intended) complexities of non-post frame foundations.

Excavation, rebar and welded wire mesh in place for a thickened edge slab foundation for stud wall construction. In this case slab edges require a double row of rebar where thickness will be 16 inches. This foundation and floor system assumes a light weight building and must be poured upon undisturbed or properly compacted soil with adequate load bearing capability. Shallow foundation and concrete slab on grade are poured concurrently.

For an engineered steel building, foundations are more complex than for post frame construction. There is a continuous footing and foundation wall around the building perimeter, with reinforced piers to support steel column bearing points. Piers have embedded anchor bolts (requiring exact and accurate placement) to attach steel frame bases.

Top of foundation wall allows for attaching steel wall panels as well as support for any masonry veneer, if required for aesthetic purposes. Each steel column base has a rebar hairpin (usually two 20 foot long rebar sticks). These hairpins tie columns into concrete floor to reduce the tendency of column bottoms to move outward when loads are applied to the building.

Post frame (pole barn) construction utilizes a low-tech foundation system able to be successfully completed by even semi-skilled workers or an average DIY building owner. Face it, augering a hole in the ground makes for a fairly simple and affordable foundation system – eliminating any need for extensive excavations, often with a need for expensive equipment.

Looking for a design solution for your new building with flexibility and cost effectiveness? In most cases, look no further than post frame construction!

 

Is Hansen a Pole Building Contractor?

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: How are the pre-engineered pole barns set up.. does Hansen provide the delivery and installation? Is the slab included in the installation? Or would the slab be by “others”? Question from Ashley in Austin, TX

DEAR ASHLEY: Hansen Pole Buildings delivers custom designed pole (post frame) buildings to building sites everywhere in the continental United States, or to the docks if shipping to Alaska or Hawaii. The buildings are designed for the average person who can and will read instructions to successfully construct their own beautiful buildings.

We are not a pole building contractor, so we do not build or install anything for anyone anywhere. If you are not interested in building yourself, we can assist you in finding a contractor who can assemble some, or all, of your building kit package for you. Many of these same contractors may be qualified to provide the labor to finish a concrete slab as well.

Mike the Pole Barn Guru

DEAR POLE BARN GURU: I have a 40’x80′ metal sided pole barn that is insulated in the ceiling and walls with double bubble reflective insulation and no venting system. Don’t have any condensation issues but it gets really hot in our Okie summers. Would some sort of vents or vent fans in the ends of the building be an effective way to mitigate the heat? Thanks in advance, just found your site and really like the access to good info. Mike in Blackwell, OK

DEAR MIKE: Thank you very much for your kind words and for becoming a reader! While you might start with trying just gable vents located as high up in the endwalls as possible, it is very probable you will need to use powered fans in order to move enough air out to make a difference. Whichever choice you pick, make some provision to close them off in the winter if you are intending any sort of heating in the cooler months.

Mike the Pole Barn Guru

DEAR POLE BARN GURU: How would a rebar cage for a base plate be constructed in the right way for a horse barn? I am interested in the step by step method once you have the hole, of implementing a rebar cage in the right position, pouring the concrete and then placing the base plate. ALMOST IN AUSTIN

DEAR ALMOST: My best guess is you are actually considering constructing a steel framed barn of some sort. Historically steel framed barns are not the ideal design solution when it comes to stabling horses. The steel framework makes it difficult to attach wood stall components to, and the concrete required at ground level poses a hazard to horses.

I’d strongly urge you to consider a pole building instead. One of the wonderful thing about pole buildings is they do not require complicated, expensive and time consuming rebar cages to be poured into significantly large concrete piers. By utilizing properly pressure preservative treated wood columns, embedded into augered holes in the ground, it eliminates the need for perfectly placed base plates (or base plates at all).

Mike the Pole Barn Guru