Developing a good understanding with your Self Tapping Screws
Developing a good understanding with your Self Tapping Screws supplier is the first step toward avoiding blowouts. If the delivered mix is too soupy, the extra water creates higher pressure which increases the number of leaks and blowouts. Most manufacturers recommend a five-slump mix of 3000 psi concrete.
Just in case, keep these blowout repair supplies on hand: two 3x3 ft. pieces of plywood and threaded rod. There should be a hole in the center of the plywood that has the same diameter as the rod. If a piece of foam bulges or pops, cut through the foam, scoop out some concrete and replace the foam. Then press the plywood over the spot. Slide the rod through the hole in the plywood and keep pushing until the rod extends through the form on the far side. Slide the other piece of plywood over the rod. Thread washers and nuts onto both ends of the rod and tighten them up.
Because the forms stay in place, you'll never see voids that remain in the wall. So, you should invest some extra effort to prevent voids. First ask the concrete supplier to add plasticizer to the mix. This makes it slippery, so it flows better around obstructions.
Some manufacturers suggest vibration to eliminate voids. Corners may need special attention, because extra spacers can sometimes create voids. A few taps (gentle taps) with a hammer can help the concrete flow around the obstacles.
One builder uses a special needle-shaped vibrator. Following the pumper, a worker sticks the vibrator into the concrete every 3 to 4 ft. It only needs to run for a couple of seconds. Too long will bring water to the top.
Another builder, who uses sheet foam forms, takes the blade off a reciprocating saw. During the pour, he hits the tie plates for 10 to 15 seconds. He does this every three or four ft. along the form.
A few builders noted that the forms were a hair off the published dimensions. One builder's 40-in. blocks were slightly less than 40-in. long. Over a long wall the accumulated error added up to over one inch.
Electrical and Plumbing
Nearly every builder agreed that installing wiring is straightforward. Using a router or a shaped hot knife, they make a groove in the foam just the right size for electric cable. Space for shallow boxes is cut out and boxes are glued or screwed to the concrete. Using a hotknife on foam can be faster than drilling studs in standard wood framing. Think ahead, you may have to preset a few vents, drains and electrical conduit.
According to manufacturers, drywall and siding can be attached directly to the walls. On sheet forms, screws can grab hold of the tie plates. Other systems rely on non-solvent-based adhesives and screws driven into the wood sill plate.
Like any new system, insulated concrete forms require some getting used to. The first two or three projects will be full of lessons. To reduce the cost of those lessons, call on the manufacturers for technical support. Most builders report strong support.
The only way to find out how a new system works, is to give it a try. If you would like to start small, make your first Phillips Wood Screws project a simple foundation. That's a low-risk way to see what all the hoopla is about.