Planning to build a gazebo where the floor joists are only 45x70. It is intended to stand on the ground with type concrete blocks or cement slabs underneath. I want to raise my gazebo so that the floor is at the same level as my deck floor, which means I plan to place it on posts. A post at each corner, and the floor should be about 400 mm above the ground. On the posts, I'll lay a framework of a heavier dimension, but my question is: how thick should the floor joists be to avoid sagging in the middle of the gazebo? The gazebo is octagonal with an outer dimension of about 3300 mm.
Some information is missing for you to get a good answer. I interpret your solution as 45x70 studwork resting on thicker beams, which in turn lie on some kind of blocks. What is the maximum length for each beam and at what distance should they be placed from each other? Ideally, a small simple sketch would be best.
I thought I was quite clear in my description... You have interpreted me correctly. I plan to place the heavier studs on buried plinths. The maximum length is about 3300 mm and the maximum distance about 1300 mm. I'm including a drawing of the floor studs that are part of the kit. The heavier studs should lie across the lighter studs.J justusandersson said:
The rough beams that should lie across the 45x70 trusses included in the kit should not be spaced more than 1.1 meters apart. In that case, these beams need to have the dimension 45x220 and strength class C 24. This is the minimum. I would place them closer together for a more solid feel.
As you can see in the sketch, it is about 1300 mm for each wall section. I am thinking of placing a post in each corner and a strong stud to the post opposite. That will be the distance between the studs for the wall sections in the middle. Do you have any other ideas on how I should do it?J justusandersson said:
1300 mm becomes too large a dimension for your 45x70 joists in the floor. If you absolutely want to have only corner pilasters, you will need to place an additional joist (45x220) in the middle, which you can somehow suspend from the adjacent joists using noggins.
It was a solution in the style of what was highlighted in red that I referred to in my previous post. While the load on the beams decreases slightly with more beams, 45x170 is insufficient. 45x195 is borderline. For acceptable deflection, 45x220 is required.