Is standard concrete used in making PERMA-COLUMNS?
NO! Perma-Columns are poured in a controlled environment using the latest pre-casting and curing technology. Additives are incorporated to enhance strength, density, corrosion and freeze-thaw resistance, yielding a High-Density concrete that has a compressive strength of more than 10,000 psi - normal concrete is often only 3,000 psi! Concrete is the most proven foundation material know to mankind...with centuries of success.
How is the steel “U” bracket attached to the concrete?
There are four strands of 1/2” or 5/8” of weld-grade rebar (size depends on the model), which are robotically welded to the steel “U” bracket. Rebar runs all the way to the bottom of each pre-cast concrete Perma-Column.
How is the post-frame building’s “skirtboard” or “splashboard” attached to the concrete?
Hammer-drill a 3/16” diameter hole through the splashboard and into the concrete, and use a HDG split-drive anchor to secure the skirtboard (a.k.a. “splashboard” or “bottom girt).
How deep should PERMA-COLUMNS be placed in the ground?
PERMA-COLUMNS are slightly wider in the dimension that resists lateral loads, thus decreasing embedment requirements. They are designed to have a base depth equal to or less than a standard wood column. Typically they are embedded four feet in the ground or less, but two Column Extenders are available to allow deeper footings: 12” (for 5’ hole depth) and 24” (for 6’ hole depth).
Do PERMA-COLUMNS need to sit on a concrete footing?
It is recommended that the same type and size of footing be used as for a wood support column, to ensure proper load-bearing requirements are achieved.
How are the galvanized uplift anchors connected to the PERMA-COLUMN?
A steel pipe is welded to the base of the four vertical reinforcing rods, creating a sleeve in the base of the PERMA-COLUMN. Just bolt the uplift anchor or column extender on through the hole.
What if the embedment depth exceed the five foot length of a standard PERMA-COLUMN?
Just connect a 12” or 24” column extender (stilt) to the base of the PERMA-COLUMN. Pour concrete around the extender to create a combination footing and uplift anchor.
How do PERMA-COLUMNS compare in cost to other concrete foundation alternatives for post frame construction?
Upgrade cost from a treated wood post foundation is typically only $10.60 per linear foot of exterior perimeter wall. PERMA-COLUMNS provide the quickest and least expensive option compared to all other concrete foundation options, and they are the most convenient … there is no waiting on a concrete sub-contractor to complete his work before the builder moves in! Also, unlike a monolithic slab, the structure won’t “float” and the steel brackets and wood columns are elevated 12” to 18” above the floor.
How do you make them even in height / depth?
Similar to a treated wood column. Attach a transit to the boom on your auger or tape a 1x” strip of wood to the bottom of the transit that extends below grade to dig holes to the same depth. The post or the outside plies on top of a wood laminated column should stick up higher than the truss - cut them off later. The pocket in a laminated column should be lower than your bottom chord height so you can insert a block the right length between plies to make the bottom of the truss the right height; or notch or bolt a block on a solid-sawn post at bottom chord height. Use pre-cast or composite footings with uplift anchors; or place a sack of dry concrete in the bottom of the hole, put the Perma-Column in with rebar where the uplift anchor goes and level it, then add another concrete sack and dirt on top of that. ASABE 486 post embedment standard approves in-situ hydration of concrete footings, so the ground humidity may set the concrete or you can water the holes after installing girts if the ground is dry.