ᐅ 150 kg/m² live load for garage roof with option to convert into a roof terrace?
Created on: 12 Sep 2017 18:22
J
Judyyy
Hello,
From the beginning, we informed the architect that we wanted to keep the option open to use the solid garage roof as a rooftop terrace.
Now that the house construction is about to start, he told me that the garage was only designed for 150 kg/m² (31 lbs/ft²), while a proper rooftop terrace should be designed for 400 kg/m² (82 lbs/ft²). He also mentioned that he has no concerns about the 150 kg/m² (31 lbs/ft²) load, since the intermediate floor in the house is designed for the same load, and the total roof load capacity should be considered...
70 m² (750 ft²) x 150 kg/m² (31 lbs/ft²) = 10,500 kg (23,150 lbs) = 10.5 tons
Of course, that sounds like a lot at first. That would be about the weight of 8 cars. Still, I have some concerns.
I would be interested to hear your opinions.
Best regards,
Judyyy
From the beginning, we informed the architect that we wanted to keep the option open to use the solid garage roof as a rooftop terrace.
Now that the house construction is about to start, he told me that the garage was only designed for 150 kg/m² (31 lbs/ft²), while a proper rooftop terrace should be designed for 400 kg/m² (82 lbs/ft²). He also mentioned that he has no concerns about the 150 kg/m² (31 lbs/ft²) load, since the intermediate floor in the house is designed for the same load, and the total roof load capacity should be considered...
70 m² (750 ft²) x 150 kg/m² (31 lbs/ft²) = 10,500 kg (23,150 lbs) = 10.5 tons
Of course, that sounds like a lot at first. That would be about the weight of 8 cars. Still, I have some concerns.
I would be interested to hear your opinions.
Best regards,
Judyyy
T
toxicmolotof12 Sep 2017 21:51I am still not a structural engineer, but I recommend consulting one.
If you look up the term live load on Wikipedia, it lists a uniform load of 4 kN/m² (85 psf) for roof terraces.
This means (expressed incorrectly) 400 kg/m² (82.8 lbs/sq ft) AFTER the floor structure. So, 400 kg plus paving slabs, substructure, waterproof membranes, insulation, etc. Therefore, you would probably need to account for around 600 kg/m² (123.1 lbs/sq ft). That’s almost the same as what the architect suggested. It should be fine.
!!! WARNING: LIFE-THREATENING HAZARD !!!
If you look up the term live load on Wikipedia, it lists a uniform load of 4 kN/m² (85 psf) for roof terraces.
This means (expressed incorrectly) 400 kg/m² (82.8 lbs/sq ft) AFTER the floor structure. So, 400 kg plus paving slabs, substructure, waterproof membranes, insulation, etc. Therefore, you would probably need to account for around 600 kg/m² (123.1 lbs/sq ft). That’s almost the same as what the architect suggested. It should be fine.
!!! WARNING: LIFE-THREATENING HAZARD !!!
toxicmolotow schrieb:
Which intermediate floor in the house can hold 150 kg/sqm (31 lbs/sq ft)? Any concrete floor slab between levels. If there is a balcony on it, even 350 kg/sqm (72 lbs/sq ft). No joke: this is required because during the Kaiserreich era people used to store briquettes on balconies. The same regulation should apply to roof terraces.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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toxicmolotof12 Sep 2017 23:49@11ant
You didn’t understand the point of my question. I really hope it supports significantly more load.
And with 3.5 kN, as far as I know, you no longer get a balcony approved in Germany, whether with or without bricks. It shouldn’t be possible to go much below 4.0 kN.
You didn’t understand the point of my question. I really hope it supports significantly more load.
And with 3.5 kN, as far as I know, you no longer get a balcony approved in Germany, whether with or without bricks. It shouldn’t be possible to go much below 4.0 kN.
150 kg/m² (31 lbs/ft²) is not that much; two adults dancing on it would already cause it to break through if it weren’t reinforced concrete (floor slab).
When I see how much our empty sliding door wardrobe weighs, plus the laminate flooring... I’m glad the ceiling can support more than 150 kg/m² (31 lbs/ft²).
When I see how much our empty sliding door wardrobe weighs, plus the laminate flooring... I’m glad the ceiling can support more than 150 kg/m² (31 lbs/ft²).
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Trasher1913 Sep 2017 10:22I just had the same issue with my prefabricated garage and have already discussed it with the manufacturer. Initially, we planned for a load capacity of 250 kg/m² (Allgäu region) due to snow load, but after expressing the intention to possibly build a roof terrace later, the recommendation was definitely to increase this to 500 kg/m². The construction company agreed with this assessment. The additional cost to upgrade from 250 to 500 kg/m² was €250.00 net, so not very expensive.
Trasher19 schrieb:
The additional cost from 250 to 500 was €250.00 net, by the way. So not a huge amount. Is that for the entire roof area (single or double garage)? – and what type of roof structure?
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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