Floating Slab Questions and Answers!
Hello Everyone!
We've received many questions about the installation and construction of the pre-engineered floating slab system included in our Garage & Barndominium Kits and we are here to explain the system.
Similar to the structure, the floating slab kit utilizes a light-weight 16 gauge steel channel with a galvalume coating to ensure they last a lifetime. The channels are no larger than 10' in length and weigh less than 40lbs, so they are easy to maneuver into place and are fastened together with standard hardware (also included).
The kits also utilize high-strength threaded rebar that is 3X stronger than conventional reinforcing rebar used in concrete forming. Again, similar to the channels the threaded rebar is no longer then 10' in length, 15lbs and are connected together with a threaded coupler. What is a coupler? Good question! It's a thing that connects two things together and in our case, 2 pieces of threaded rebar. The couplers included have a pin at the mid-point so you cannot over thread it onto one piece vs. the other, keeping the system safe and secure!
All foundations require some form of insulation to resist frost heave and our slab kit are no exception to this rule. All of our Barndominium kits include full rigid insulation below the slab and around the perimeter. This insulation is not your typical insulation. This insulation is high density, 2.5" thick, and has an r-value of 10.5. What does all this mean? Standard insulation has a compressive strength of 15 psi (pounds per square inch), meaning that if you walk on it, it will compress. Our system uses an insulation with a compressive strength of 30 psi, which is twice as strong as standard rigid insulation to resist the deflection and transfer the loads to the ground equally. The "r" in r-value refers to the resistance to heat flow and the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power!
Now that we have talked about the three main aspects of the floating slab (perimeter channel, threaded rebar and insulation) you may be wondering how they connect together. First, a rebar nut threaded on to the rebar and then it is placed though pre-drilled holes in the perimeter channel. Another threaded nut is placed on the exterior side of the channel, sandwiching the perimeter channel between the two nuts. This helps maintain the floating slab dimensions and allows the system to remain tensioned for it's lifetime. It's worth noting that all perimeter channels, rebar nuts, and threaded rebar remain in-place so there is very minimal clean up. The kit also includes pre-drilled anchor bolt plates that interact perfectly with the structure. These anchor bolt plates are simply screwed to the perimeter channel in the location noted on the supplied drawings and the anchor bolts are then placed in the pre-drilled holes.
Once the kit has been assembled and levelled, you are ready for the final step—concrete. Our foundation kit will utilize 32mpa concrete and fibermesh (tiny fibrous strands of extra reinforcement) which further enhances the structural integrity of the system. This system is built to resist cracking and relief cuts are not recommended as they will weaken this system. Once ready, the concrete for the system can be arranged and finished by any concrete finisher in your area.
With that, we leave a segue into next week's newsletter on some of the methods you should use to vet a builder and what to look for.
-- Eric & Kyle