Laserfiche WebLink
Inwood 10 LLC <br />Project B14-08413 <br />December 3, 2014 <br />Page 10 <br />150 pounds per square inch per inch of deflection (pci) to design the slabs. If 6 inches of compacted <br />aggregate base is placed immediately below the slab, the k- value may be increased by 50 pci. An <br />aggregate base will also be a more stable platform for construction equipment during construction and is <br />less weather sensitive. <br />D.3.b.Moisture Vapor Protection <br />As large portions of the building are anticipated to have an exposed concrete floor, vapor transmission <br />through the floor may not be a major concern. However, it may still be a benefit to put a vapor barrier <br />below the floor due to: <br />Materials placed on the floor may be damaged by absorbed moisture. <br />Less water vapor in the air may result in a reduction in heating and cooling costs. <br />The vapor barrier will be in place for any future remodeling. <br />Excess transmission of water vapor could cause floor dampness, certain types of floor bonding agents to <br />separate, or mold to form under floor coverings. If floor coverings or coatings less permeable than the <br />concrete slab will be used, we recommend a vapor retarder or vapor barrier be place immediately <br />beneath the slab. We recommend consulting with floor covering manufacturers regarding the <br />appropriate type, use and installation of the vapor retarder or barrier to preserve warranty assurances. <br />We recommend the vapor retarder or barrier be observed prior to concrete placement so holes, tears or <br />gaps in the vapor retarder or barrier can be identified and patched or realigned as needed. We further <br />recommend performing moisture vapor transmission tests after the concrete slabs have cured, but <br />before flooring are installed. Flooring manufacturers typically recommend upper limits of moisture vapor <br />transmission can be used to set schedules for flooring installation but, more importantly, may impact <br />warranties. <br />D.4.Exterior Slabs <br />For general exterior slabs we recommend subgrades be prepared similar as to what is described in <br />section D.6 for pavements. If portions of the exterior surface will have higher expectations for <br />performance for example a paver patio, additional preparations would be recommended to limit frost <br />heave and post construction settlement. <br />We anticipate exterior slabs will be underlain with silty sands, which are considered moderately to highly <br />frost susceptible. If these soils become saturated and freeze, unfavorable amounts of heaving could