Reinforce joists 6m span

Johan_86 · 2018-11-26T20:19:18+00:00

Hello, I am planning to reinforce a floor in a room that measures 6200 x 7200mm. The current beams are approximately 270x200 and are spaced at 1000cc. The floor is made of tongue-and-groove boards about 40mm, but it sags severely. Deflection is about 50mm in the middle compared to the edges. What complicates the project is that there is a really fine ceiling painting in the plastered ceiling of the room below, so the utmost care needs to be taken to avoid cracks. I can go up about 20mm above the existing beams and still make it look nice with a new tongue-and-groove floor. I am considering glue-laminated timber 270x90, but 270x115 in the middle. The new beams would then be placed 10-20mm above the existing ceiling to allow for some deflection. Reinforcement would be along the existing beams as well as cross beams. Am I on the right track? Do you see any other options? I realize it will be costly with so much glue-laminated timber, but pillars are not an option. Best regards