Hello,
I have an older sunroom with glass panels in wooden frames, which I planned to replace with aluminum panels. The sunroom is 5400 wide and 4000 deep. It is currently built with 70 x 70 posts in the corners and 2 pieces of 70 x 70 posts evenly distributed on the front edge. The roof, which is a single-channel plastic roof with aluminum rails, is reinforced with 45 x 120 joists, which in turn rest on double 45 x 160 joists in the load-bearing beam. The slope is approximately 15 cm over the 4 meters.
I am now thinking of removing the two posts at the front of the sunroom and replacing them with a crossbeam of some sort, to allow for sliding sections across the entire front, but since I don't want the beam to restrict the height of the sliding sections too much, I am afraid that the option of using a laminated wood beam can be discounted. And then some form of metal beam remains, I guess?
I have space for a beam that is 100 - 120 mm high, and the span will be 5350 mm.
What kind of beam can be used that does not sag too much in the middle, and that can handle snow load, etc., which must be accounted for? Now, I live far down in Skåne, so we don’t have that much snow, but it must be taken into account. I have contacted some companies that sell beams, but they are directly unwilling to help with any form of calculations as they do not want to take any responsibility.
So I guess I have to reverse the question and wonder which type of beam has the highest load-bearing capacity and least sag in the middle at a length of 5350 mm and at a height of 100-120 mm? Can anyone help me with that?
I have an older sunroom with glass panels in wooden frames, which I planned to replace with aluminum panels. The sunroom is 5400 wide and 4000 deep. It is currently built with 70 x 70 posts in the corners and 2 pieces of 70 x 70 posts evenly distributed on the front edge. The roof, which is a single-channel plastic roof with aluminum rails, is reinforced with 45 x 120 joists, which in turn rest on double 45 x 160 joists in the load-bearing beam. The slope is approximately 15 cm over the 4 meters.
I am now thinking of removing the two posts at the front of the sunroom and replacing them with a crossbeam of some sort, to allow for sliding sections across the entire front, but since I don't want the beam to restrict the height of the sliding sections too much, I am afraid that the option of using a laminated wood beam can be discounted. And then some form of metal beam remains, I guess?
I have space for a beam that is 100 - 120 mm high, and the span will be 5350 mm.
What kind of beam can be used that does not sag too much in the middle, and that can handle snow load, etc., which must be accounted for? Now, I live far down in Skåne, so we don’t have that much snow, but it must be taken into account. I have contacted some companies that sell beams, but they are directly unwilling to help with any form of calculations as they do not want to take any responsibility.
So I guess I have to reverse the question and wonder which type of beam has the highest load-bearing capacity and least sag in the middle at a length of 5350 mm and at a height of 100-120 mm? Can anyone help me with that?
The difficult part here is not calculating the beam - the tricky part is calculating the loads. What snow zone is the building in, what roof angle, what roof construction do you have?
You can reduce the height a little if you calculate the beam as fixed-restrained. Personally, I calculated it as simply supported but screwed it onto brackets as the "icing on the cake" since I couldn't quite meet the deflection requirement.
Keep in mind that your beam will move when it takes load. You must therefore place some material that accommodates these movements between the glass partition and the beam. In this case, the glass partition should really be considered as a regular curtain wall.
You can reduce the height a little if you calculate the beam as fixed-restrained. Personally, I calculated it as simply supported but screwed it onto brackets as the "icing on the cake" since I couldn't quite meet the deflection requirement.
Keep in mind that your beam will move when it takes load. You must therefore place some material that accommodates these movements between the glass partition and the beam. In this case, the glass partition should really be considered as a regular curtain wall.
Unfortunately, you won't find a beam that meets the height requirement of 100-120 mm. You must use posts, and it shouldn't be a problem since foldable panels can't be fully opened anyway. For example, a three-part section can have two posts. But maybe you've looked at sections that fold together?
Snow zone - Skanör/Falsterbo, don't know which snow zone it belongs to.
Roof pitch - Well, as I wrote, about 15 cm fall over 4 m.
Roof construction - It's a plastic roof, 1-channel, with battens and a bearing beam as I described earlier. In other words, it's not heavier than I can probably support the front edge myself when the posts are removed. I think any potential snow load is what you need to be most prepared for.
Because I don't want to have any posts remaining at the front edge, there will be 5 sliding sections that should be slid in one direction, and I want to be able to slide them away completely.
Roof pitch - Well, as I wrote, about 15 cm fall over 4 m.
Roof construction - It's a plastic roof, 1-channel, with battens and a bearing beam as I described earlier. In other words, it's not heavier than I can probably support the front edge myself when the posts are removed. I think any potential snow load is what you need to be most prepared for.
Because I don't want to have any posts remaining at the front edge, there will be 5 sliding sections that should be slid in one direction, and I want to be able to slide them away completely.
If the conservatory is connected to a house, more information is needed to account for snow pocket, etc., but it's likely that a HEB120, which is 120 mm high (and equally wide), will be sufficient. It will hold with a good margin but will bend down a couple of centimeters in the middle under heavy snow load. If you want to avoid issues with sagging, you can shovel the roof during snow-rich winters.
Is the HEB the beam with the least deflection?
Could a so-called VKR tube be an alternative? Would such a "tube" become more stable if it were filled with, for example, a wooden beam that fits precisely inside? Let's say a VKR 100 x 60?
Could a so-called VKR tube be an alternative? Would such a "tube" become more stable if it were filled with, for example, a wooden beam that fits precisely inside? Let's say a VKR 100 x 60?
HEB is the beam that provides the lowest deflection among the most common beam types. (There is also a beam HEM100 which is 120 mm high and has a 20 mm flange thickness; it is 32% stiffer than HEB120. HEM beams are quite uncommon in Sweden, I believe, we had to bring them in from Germany when we constructed a machine base with such beams at my previous job.
A VKR-tube is a poor alternative. A VKR100x60x6.3 (on edge) results in 3.8 times greater deflection than HEB120. A wooden stud inside makes no noticeable difference.
A VKR-tube is a poor alternative. A VKR100x60x6.3 (on edge) results in 3.8 times greater deflection than HEB120. A wooden stud inside makes no noticeable difference.
No! IPE is much narrower than HEB, and thus weaker. You should compare Ix (Moment of inertia in the rigid direction) when it comes to deflection. HEB120 has 864 cm4, IPE120 has 318 cm4, meaning IPE120 will experience 2.7 times more deflection than HEB120.
Don't have time to go in-depth, but did a quick calculation with the Excel file I made when calculating my beam for the living room. With an HEB120, you can take 17.5kN/m distributed load on a 5.35 m simply supported beam without exceeding 435 MPa - but then the beam bends down over 100 mm. If you set the deflection limit to L / 400 = 13 mm, you can take 2 kN/m distributed load.
If you choose an HEM 100, you can take 2.75 kN/m at 13 mm...
...but this is not how you design - you should really follow the book and consider cross-section class, safety class, risk of buckling, and so on. An engineer will help you with a design according to BKR.
Also, consider the columns that will support the beam - I don't know if you're planning to use wood there, but it could be tricky. Use a KKR or equivalent instead.
If you choose an HEM 100, you can take 2.75 kN/m at 13 mm...
...but this is not how you design - you should really follow the book and consider cross-section class, safety class, risk of buckling, and so on. An engineer will help you with a design according to BKR.
Also, consider the columns that will support the beam - I don't know if you're planning to use wood there, but it could be tricky. Use a KKR or equivalent instead.
HEB120 holds, taking into account cross-section class, safety class, buckling, and all other essentials. The deflection under heavy snow loads, however, must be considered, as previously pointed out. I agree with Locke that the columns should also be dimensioned. The lateral stability should also be ensured.
Rather an intelligent question! x and y in my table are probably y and z in your table. In any case, it is the highest of the two I-values that you should look at, (bending in the stiff direction).jorgen_a said:
One can also handle some of the tasks out at the stockpile. If you weld wedged brackets and screw the beam at the ends (there are some pictures of how I did it in my tearing down heart wall thread), you reduce the deflection, but instead, you get an uneven load case on the columns. It can be calculated manually as well, but it's easiest if you go to an engineer - they have great computer programs for calculating frames and other things.