If you approach the issue of gap insulation thoroughly and very seriously, then you can perform it on the pillow. Crushed stone, sand is used as a pillow, and these structures are cast from concrete. The level of the columns is calculated, leaving the desired floor height, on which the support beams are then laid. The state of the lag is necessarily determined. If they are no longer suitable, then they should be replaced. Lags can be cleaned, for this special solutions are used, which process the lags. Processing will give the tree refractory and slow down the process of decay. Logs are cut in two, and are used under the lags most often. This option is more economical. And directly, before laying the lag, everything should be well thought out relative to the material that will serve as waterproofing. By the way, now many began to install double -glazed windows, they are not very expensive.