L
Leofric
They require structural calculations by a structural engineer who will knows what is required , but who is dealing with building regulations approval and how are they doing it
Long/reinforced roof joist options
- Thread starter d000hg
- Start date
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Looks like it'll be the local council. They seem inclined to cut us as much slack as possible - it's basically a shed in our garden but strictly is a commercial premises over 50m2. They seem to feel it's a bit ludicrous to require every single thing that entails, I don't know how much discretion they have.
L
Leofric
Yes, but who is dealing with the local authority building control
who feels what is ludicrous If Building Control do their job properly they check that buildings comply with building regulations
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It's purpose made, which means it is bespoke designed based on our floorplan. But it seems they realised their design method required bracing, and didn't tell us.And I thought it was a purpose made, off the shelf log cabin - which you tend to buy to avoid having to mess about thinking or designing it.
I have updated the first post: plan diagrams and updated text. I don't know if this type of roof has a specific name?
In an ideal world, yes. In practical terms when it's already in the factory, we don't want to risk long delays when everything is planned around it's arrival date
People do modify these all the time apparently. I think our strategy would be that of they can't modify it in a timely fashion - I'm not even sure their design method allows for long spans - we'd request some compensation to get us to sort it out.
People do modify these all the time apparently. I think our strategy would be that of they can't modify it in a timely fashion - I'm not even sure their design method allows for long spans - we'd request some compensation to get us to sort it out.
Hi Again. If the building is for commercial useage it not going to come under Domestic BC. I'd speak to them to confirm exactly what it is going to be used for and how many people will be working there and what sort of materials you will be working with as a business. You don't want them thinking it just one person self employed as a hobby shed/workshop. Plus its not just about the building of the cabin it's the insuring of it afterwards too. If you going for a full open plan design the roof trusses or joists will have take the load of the ceiling and roof. Before as i mentioned it's the load bearing capabilities of the outer walls that will have to be taken into consideration too. Have a read of a site like this to explain things.
https://precivil.com/types-of-walls/
A lot of cabins use interlocking logs or a basic frame with the lop lap nailed to it. With such an open span if i reading correctly that you want no internal walls then the outer walls will need to be thicker.
Personally for something this big i would ditch the firm and get a time served chippy to build.
If i was building myself it would be a case of 8 x 4 18mm structural ply/OSD with 4 x 2 framing on each board. These wall sections would be bolted together with a 6 x 6 wooden post inbetween with the i-beam coming off them across the room or roof trusses. Plyboard or structural OSD for the roof with the shingles over a roofing membrane. The whole frame would be rapped in framing membrane them batterned out and cladding of your choice. The 4 x 2 frame is filled with rigid insulation then a mutli foil with vapour barrier then boarded.
https://precivil.com/types-of-walls/
A lot of cabins use interlocking logs or a basic frame with the lop lap nailed to it. With such an open span if i reading correctly that you want no internal walls then the outer walls will need to be thicker.
Personally for something this big i would ditch the firm and get a time served chippy to build.
If i was building myself it would be a case of 8 x 4 18mm structural ply/OSD with 4 x 2 framing on each board. These wall sections would be bolted together with a 6 x 6 wooden post inbetween with the i-beam coming off them across the room or roof trusses. Plyboard or structural OSD for the roof with the shingles over a roofing membrane. The whole frame would be rapped in framing membrane them batterned out and cladding of your choice. The 4 x 2 frame is filled with rigid insulation then a mutli foil with vapour barrier then boarded.
Oooh forgot to ask. What sort of base is this going on ?
Hey Martin, thanks for that.
If you see from the plans, the roof is supported on 5 'trusses' which are really just walls except that one with the pillar. The only changes we are thinking about from what you see there are:
Even so, as you say that will distribute some load to the outer walls but the roof is very lightweight - shingles. If you look at the middle of wall 5 you can see they actually already beef up the outer wall (between the windows they have basically built an intersecting pillar), we could do more if required:
We aren't planning to just go bodging this in, just to clarify. If the company isn't able to do it in a timely way we'd get someone to sort it properly but I'd like to ascertain what should be possible in layman's terms, get a few ideas.
In hindsight, I might have made more alterations but realistically, what I'm essentially proposing is to make this change:
If you see from the plans, the roof is supported on 5 'trusses' which are really just walls except that one with the pillar. The only changes we are thinking about from what you see there are:
- removing the upright beam right in the middle of the main room
- wondering about the partition from eave height upwards on wall 3 - can't see what it does unless it's for longitudinal bracing?
Even so, as you say that will distribute some load to the outer walls but the roof is very lightweight - shingles. If you look at the middle of wall 5 you can see they actually already beef up the outer wall (between the windows they have basically built an intersecting pillar), we could do more if required:
We aren't planning to just go bodging this in, just to clarify. If the company isn't able to do it in a timely way we'd get someone to sort it properly but I'd like to ascertain what should be possible in layman's terms, get a few ideas.
In hindsight, I might have made more alterations but realistically, what I'm essentially proposing is to make this change:
- Remove the red upright
- replace the bottom two rows (orange) with a single-span member of some sort.
Yes, this has been communicated to BC. I think they are classing it as "non dwelling - other" since it's an addition in our garden from which some business activities happen. Hence need for SBEM and so on.
It is already in manufacturing so we're kind of stuck with making the best now
It is going on a wooden 'raft' base supported on plinth foundations. These guys designed based on our cabin spec and topographic survey to figure out how many we needed for load bearing: https://swiftfoundations.co.uk/swift_plinth/
Hope this better to understand. Black lines = retro fitted beams at ceiling level. X = pillars at end of the internal walls or inside each wall.
Should of mentioned if the company can incorparate into the building of the cabin for you.
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