REPAIR AND STRENGTHENING OF FLOORS ON WOODEN BEAMS
Authors: Yakymenko Oleh , Romanova Anastasiia 
Published: August 2021

Methods of repair and strengthening of floors on wooden beams are investigated. The main causes of defects are analyzed. The analysis is carried out and the advantages and disadvantages of methods of repair and strengthening of overlappings on wooden beams are defined. As a result of comparison of methods the conclusion is made.
In the buildings constructed to 60th years the overlapping on wooden beams with a step of 80...120 cm was usually used. It is carried out integral – from logs or bars or component – from several boards or bars established «on an edge» and connected with nails or nails. Beams covered with wooden beams are up to 10 m or more. In the latter case, the beams in the middle of the run are usually supported by load-bearing partitions.
When choosing a method for repairing and strengthening floors, it is necessary to take into account the subsequent use of buildings and structures. If the service life of buildings and structures does not exceed 20...25 years, you should make the most of existing load-bearing structures, be sure to keep the load-bearing partitions. In case of longer terms of use and impossibility to use available systems of partitions it is necessary to provide unloading metal rungs with additional internal support or to replace overlappings.
During repair and construction works on floors, the following types of work are usually used: replacement of beams, strengthening the ends of beams near supports or in the run, elimination of excessive deflections, restoration of thermal and sound insulation properties of filling, complete or partial replacement of rolling and filing, partial or complete replacement of floors.
Wooden beams are replaced in case of their complete decay or damage by house fungus. The work is performed in the following sequence: disassembly of floors, preparation of nests in the walls for supporting beams, installation of wooden beams, laying beams, restoration of rolling and backfilling, installation of new flooring.
Individual beams are usually replaced without disassembling the roll and removing the backfill in two runs. In this case, parallel to the replaced beam on the temporary supports at the bottom of the floor set two temporary supports to support the ends of the roll and replace the beam with a new one, resting on it cranial bars and a package of insulation. After that, the temporary supports are dismantled, the bottom of the new beam is plastered, and logs are laid on top and the floor covering is restored. During the preparation of the support beams (nests) in the inner wall, a through hole is drilled to install the beam in the design position. If it is not possible to punch a through hole, the beam is made of two parts.
Installation of wooden beams includes the following operations: preparation of support surfaces, cleaning and preparation for reuse of existing anchors. In the design position of the beam is wound at an angle of 15...20° to the horizon at one end in a pre-prepared nest, the height of which is 0,4...0,6 m, and the depth exceeds the minimum size of the support by 0,15...0,2 m. Then the beam is fixed in horizontal position and in the return movement establish in a place, anchor it and warm end faces from possible freezing, leaving thus for airing a gap of 40...50 mm.
The height of the new beams is determined by the dimensions of the existing floor structures and must be not less than the height of the replacement elements. The width of the beams must be confirmed by calculations.