To cut or not to cut a slab?

Is there any known benefit (increased isolation) to cutting a concrete slab? I am ready to begin construction on a basement studio. Unfortunately, the slab is only 4" thick and is layed over several inches of sand. The budget is still being determined, but there will not be enough funds available to float the floors. We are considering using the RSIC clips or Isomax clips on a single-stud wall for all interior walls. From a common sense viewpoint, this may negate any gains made by cutting the slab between adjacent rooms versus a double stud arrangement. Complete isolation is not a requirement, but cutting concrete is relatively inexpensive and therefore worth consideration. I am planning to use neoprene to decouple the walls from the slab and ceiling as much as possible. I am still looking for a good method of attaching the plate to the slab without compromising the neoprene. Any thoughts on that subject would be welcome as well. Thanks, Don

Don, welcome; I'd not cut the slab in your situation, single walls just won't justify it even with RSIC clips - and especially if it's on sand instead of compacted gravel. Also, if you're using RSIC's on one side there's no need to put neoprene under the plates; there's a good chance all you'd accomplish is to create an un-wanted resonance between the mass-spring-mass of the wall, neoprene, and floor. Instead, I'd just use a commercially available Thermal Break material like Sill Seal, or a couple layers of 30 pound roofing felt, under the plates and bolt 'em down with lag shields and washers. Let the RSIC clips do their job of isolating your inner wallboard layers from the frame, caulk well, follow all the info on methods, etc, in the REFERENCE section and you should be good. If your upper floor joists can take it, you'll improve isolation to the rest of the house by adding a couple layers of drywall up against the subfloor from below; do a search here on "beef" for more. Plan on a complete insulation fill and at least two layers of 5/8 drywall on the RSIC system, don't use any insulation you can't BLOW through (no foam board), and don't use any vapor barriers ANYWHERE without researching it first (mold) Speaking of which, you'll need to assess just how DRY your basement is/will be; may wanna plan on a dehumidifier that runs 24/7 except while using the space. IF your place shows ANY signs of moisture, I'd stay away from metal studs; wood can live with about 10 TIMES the moisture level before causing problems. For a better understanding of all the possible problems involved with basement living space, check out the Building Sciences links in the REFERENCE section - there are several pdf's that are really educational. HTH... Steve

Thanks very much for your prompt reply. The moisture issue is a great concern at this time. There has been some infiltration following large amounts of rainfall despite professionally applied elastomeric waterproofing and drainboard. The footing was formed with a product called Form-a-drain which provides a path from under the slab as well as collecting water on the exterior. There is also a redundant French-drain system (The waterproofing warranty required this!). These systems are joined together with the downspouts from the gutters and piped greater than 30 feet away from the house. The above-grade blocks were treated with Siloxane, block filler, and two coats of latex paint. Water is still getting in somehow. Construction will not likely begin until someone can determine the source and a best approach. Don

Don, I'd take a close look at any and all FLASHING at each level of your house; maybe the water's following a poorly done flash job inside and down... Steve