7. Subfloor and Second Floor

Trusses vs I-Joist. Stick framing the floor for the second floor is obsolete. So we will not discuss it as an option.
I-joist, the quiet floor. This is a relatively new flooring system that uses two by two's on the top an bottom of O.S.B. ( oriental strand board ) for the flooring. The system is suppose to eliminate floor squeaks and sagging. The biggest benefit is cost. Now some of the problems, or should we say disadvantages of the floor. First the rules on where you can cut through the joist for plumbing and electrical are different from what most installers are accustomed with. If you do have a miss cut you need an engineer to give you a signed/sealed plan for the repair. This could cause time delays and unwanted back-charges to one or more of your mechanical contractors. You also have to be careful on how you run your A/C ducting. You don't want to run it across several of these in a row, or run across an entire room. This could make you have to frame additional chases for your ducts, or furr-downs. With open web trusses you have the ability to run all of your Mechanicals with out cutting anything. If you do have a truss repair, the repair is already on your plans and eliminates delays. Contractors are familiar with them and you eliminate that learning curve. Any monies saved in the use of I-joists is given back in the cost of the plumber, electrician and HVAC contractor, and in some cases could cost more. Talk to a framer about nailing sub floor to I Joist which is 1 1/2 inch wide versus an open web joist which is 4 to 6 inches wide. Silent floor, most floor squeaks are created by your sub-floor not your framing. Back in the days of framing floors out with 2x 12's we had those problems. Most of the time when the floor framing squeaks it is the wood against wood or the nails against the wood back when we used ledger strips instead of joist hangers, and we had X blocking. We also used shims because no two pieces of lumber are the exactly the same width. Then we also had plywood sub floors which are great with one exception -- when they get rained on they start to delaminate. You might not hear this squeak for four to eight seasons. You have to remember lumber moves with the weather. Even kiln dried lumber has drying out to do after it has been exposed to the elements during construction. During construction your lumber is exposed to whatever the weather is at that time. It swells, bows, and warps. Hopefully very little, but a little here and a little there and soon you have places for movement. Most of your quality builders will come into your home once, at the tail end of your cosmetic warranty and fix hairline cracks. The reason is they want your home to go through four seasons, that way you have to turn your heat and A/C on. You also go through that time where you might leave windows open. This time will ensure the lumber is dried and the home has settled. Gravity, snow, furniture along with just living in the home will tighten frame members. With I-joist or open web joist you eliminate a lot of the rubbing because of how their systems designed. Sub-floor should be O.S.B. This material is not laminated and has been used for some time now. It has been in use long enough that we know it works. You have to be careful with new products and systems. Some have been very painful for the homeowner and the builder, not to mention expensive. I have used I-joist in several communities in various municipalities with great success. That is why I know it takes a lot of training of sub contractors and construction managers. Sometimes the suppliers are not sure on the proper techniques for installation. If they have been in use for a while in your part of the country and your mechanical contractors are well versed with them, I say go for it. But if it is new to your area and when you talk to contractors and they don't seem real confident --stay away. Me--I am still using open web. Make sure your strong backs are on top and you get less flex. Make sure your game rooms are designed for pool tables and if the master is upstairs make sure it can handle a water bed. I know, no one has water beds anymore, but you have to remember that the average stay for people in their home is only around seven years, and that number includes people like a lot of our parents and grandparents who stayed in their homes for decades. You want to be able to sale your home when you desire to move up, move down or get a R.V. and ride. Next time more framing