Issue link: https://read.dmtmag.com/i/119220
SERVICE & SET-UP Dry Foundation Part 2 BY GEORGE PORTER This is the second in a set of articles that promises to tell you way more than you wanted to know about frost line. Please hang in there because the old saying, "A little knowledge is a dangerous thing" is still very true. Not everyone is as interested in everyday science as me and that is fine I guess but I just can't imagine that some folks don't know or care what is going on all around them. Knowing how stuff works is interesting and fun. Most installers I know who are at the top of their game, have to know how things work so they can stay out of trouble in their business. So for those guys and anyone else who is still reading this, here is how it works. If you will recall last month's article we discussed why we have always been told that we have to dig below the frost line to be safe and we discussed that if we can keep the water saturation under 80% we can eliminate frost heave. We also mentioned that water without heat is ice. Add a little heat to bring it over 32 degrees and it changes to water. Water is a bit like those transformers that the kids play with. One minute it is solid and the next it is liquid; this is known as a transition phase. It is actually a change in the H2O molecule. Last month we also mentioned that molecules are held together by very small electrical charges that act like magnets. Remember that opposites attract so a plus charge is attracted to a negative charge. Using this principle we can create a string of molecules sticking together connected where the charges are opposite. If you have ever played with "Tinker Toys" you will remember that there were little wheels with holes all around the edges and the middle and sticks that go from one little wheel hole to the another wheel. You can make quite a structure with sticks and wheels that takes up a lot of room, maybe as big as a basketball. But… when you take it all apart it will go into a much smaller little box. Think of the structure as ice and water as the disassembled parts. When you re-assemble the parts the structure is APRIL 2013 18 THE JOURNAL big again just like it was. You have changed (transitioned) the parts into something that takes up a lot more room. With this example in mind let's think about water. Water is very special stuff! It is essential for life but I bet you didn't know just how essential. Yes we need to drink the stuff but did you know that if water did not expand when it freezes this planet would be a dead rock. If water acted like nearly every other substance on the planet and just continued to shrink when it got very cold then there would be no uplifting cold ocean currents bringing nutrients to the surface for life to feed on. The oceans would be frozen at the bottom miles thick and no food chain. When cold water expands it becomes less dense than the surrounding warmer water and floats to the top. That is why icebergs float. They are less dense than the water they sit in. So what about frost heave? Well… have you seen pipes freeze and burst? Ice is a very powerful force. In fact when water transitions from liquid to ice it expands in volume by 9% and it is said to have a lifting force of 50,000 lbs. per square inch. That is more than enough to lift and/or break anything we deal with. This force is why we have to dig below where the ground freezes so we don't get lifted by the ice. (Are you ready for this?) Unless we don't have the saturation to make the ice!! If it is dry then there is no ice formed and no lift. (Irrefutable fact- Law of nature!!) So what the heck has the construction world been doing for thousands of years? Why have they not known this and acted on this fact? They did know it but conventional construction can't use it, that's why. Conventional construction relies on a perimeter foundation directly under the outside walls. Makes sense of course that the weight of the walls and roof would be supported directly under where the weight was located. Outside walls have a foundation wall directly under them and when it rains or snows it runs right down that wall and into the ground around it; at least on one side for sure. So it is wet and there is not much you can do about it. Then there is us. Manufactured housing has that frame that is located three or sometimes four feet from the edge of the home. Over the years people have pointed to the frame and said that it made it a less than desirable home. The thing had wheels and it had to have a frame so the wheels could be attached. This was just such a sad thing that we were different. The frame affected financing, zoning, and social status of all involved. Well get over it because it is that frame that will enable us to use this dry foundation when no other type of construction can. Manufactured housing is ready made for this new technology. No other home construction can use it. (yet) If they redesign their foundation they can. Our foundation is tucked under the home protected by the roof and floor and if the lot is properly graded it absolutely will not be subject to frost heave. We have an engineer's stamp on it in 46 states and it is in many HUD approved installation manuals around the industry. This fact could save the industry and its customers as much as 6 to 8 thousand dollars on a home in the north with no compromising the structure. And all we need to do is convince some building officials that you need water to make ice. 'Seems like that should be possible. T J George Porter is a consultant to the manufactured housing industry. His Company is Manufactured Housing Resources, P.O. Box 9, Nassau, DE 19969, (302) 645 5552, Web: www.george-porter.com Some of his services are both in person and On-line training for certification in many states plus expert witness and investigation for the industry.