Pappa Posted March 18 Author Posted March 18 Thanks for the replys On 17/03/2025 at 14:02, saveasteading said: Yes. The door and the corner. You will need a brick pier or a steel column. FYI, an RSJ (rolled steel joist) is a fairly lightweight category. You will need a UB ( universal beam), probably about 300mm deep. My gut feeling is the cost is about £450. Add column , fabrication erecting, perhaps foundation. £2K? Expand So to be honest... I would rather go with 195 deep joist at 200 centers (Design 1 or 2) because splitting the span (Design 3) is going to cost me an extra couple hundred quid even before you mentioned the additional column etc. Furthermore, There will still be approx 90 joist hangers to install either way, so I can't see it making a difference in terms of labour... Obviously there is the installation of the steel beam which is more work. On 17/03/2025 at 13:17, Iceverge said: A question I had was do you have an ensuite or anything that requires pipes in the loft conversion? Expand I'm glad you raised this, I've attached some more details below. The only thing its missing is MVHR ducting. I have no idea where the ducting is coming from however. I've not thought that far.
saveasteading Posted March 18 Posted March 18 Design 1 is simplest but there is a very big load off the stair trimmer, carrying over to the wall at 2 points. Needs a check. Design 2 also needs support across the gap. SE time. 1
Iceverge Posted March 18 Posted March 18 Can you provide a ground floor plan too, if you're routing soil pipes internally you can route support posts internally. Likewise around the stairs opening, I'm sure space for a post could be found here. Do you have any sectional drawings? I get that your head room is tight but is it "that" tight? 200mm spaced joists screams wrong solution to me. I'll 'd be inclined to stay from the party wall if it's only single skin. You might do more harm than good.
Pappa Posted March 18 Author Posted March 18 On 18/03/2025 at 10:07, Iceverge said: Can you provide a ground floor plan too. Do you have any sectional drawings? Expand Thanks again More drawings attached: As things are (195mm deep joists) I'll need to cut in to the existing ballustrade and move it along by 0.263m. this is despite compromises I'm making to make the winder as narrow as possible; and ceiling has been lowered as much as possible. Thanks again P
ProDave Posted March 18 Posted March 18 Is 1.8M enough over the stairs? I thought it was 2M on the centreline of the stairs (perhaps that is only Scotland?)
Mr Punter Posted March 18 Posted March 18 On 18/03/2025 at 16:46, ProDave said: Is 1.8M enough over the stairs? I thought it was 2M on the centreline of the stairs (perhaps that is only Scotland?) Expand 2.0m. It may be OK at the top but worth checking the trimmer height at the bottom.
ProDave Posted March 18 Posted March 18 On 18/03/2025 at 16:24, Pappa said: this is despite compromises I'm making to make the winder as narrow as possible; and ceiling has been lowered as much as possible. Expand Shorten the stairs. You have 14 steps there it should easily be possible to get that to 13 and possibly even to 12 (depending on your lowered ceiling height below) by using the maximum rise per stair. Then the maximum pitch to give you the steepest , shortest stair allowed.
Iceverge Posted March 18 Posted March 18 (edited) Am I correct in thinking this is "Up" for both stairways? It'd be much easier to package if you stacked them rising the same direction. Edited March 18 by Iceverge
Pappa Posted March 19 Author Posted March 19 Thanks for all the replys guys On 18/03/2025 at 16:46, ProDave said: Is 1.8M enough over the stairs? I thought it was 2M on the centreline of the stairs (perhaps that is only Scotland?) Expand Its 2m, however they allow 1.9m if the stairs are walking in to the pitch of the roof at the middle and 1.8m at the end of the stairs. Please correct me if I'm wrong. On 18/03/2025 at 17:32, ProDave said: Shorten the stairs. You have 14 steps there it should easily be possible to get that to 13 and possibly even to 12 (depending on your lowered ceiling height below) by using the maximum rise per stair. Then the maximum pitch to give you the steepest , shortest stair allowed. Expand 14 steps is the minimum to maintain a 42 degree angle as per regs. On 18/03/2025 at 19:05, Iceverge said: It'd be much easier to package if you stacked them rising the same direction. Expand Agreed, however there are two drawbacks to that: 1) that side of the loft enjoys the best views out the window, we wouldn't be able to access those views from the master bedroom, instead we'd have to go in to the bathroom (frosted windows) and the spare bedroom. 2) That is the dormer side so the full head height ceilings would be wasted on bathroom and spare bedroom, instead the master bedroom would get the pitched roof. Thanks again.
ProDave Posted March 19 Posted March 19 On 19/03/2025 at 01:11, Pappa said: 14 steps is the minimum to maintain a 42 degree angle as per regs. Expand I disagree. I have 13 steps to rise our 2440 room height plus the 300mm joist thickness, and the rise of each stair was still less than maximum. Or do English regs give you a smaller maximum rise than Scottish? What is your ceiling height of the room below?
torre Posted March 19 Posted March 19 On 18/03/2025 at 01:06, Pappa said: only thing its missing is MVHR ducting Expand This sounds very challenging with some of your joist suggestions! I'd be very surprised if 12 or 13 stairs didn't work. At 220mm max rise that's 2640 or 2860. Try a site like stairbox and play with their options. That headroom diminishing to 1.8 is the absolute minimum so don't miscalculate and then find you need 15mm for PB On 19/03/2025 at 01:11, Pappa said: the dormer side Expand You already have a dormer at the back!? Then I'd definitely try to stack the stairs better. Given you already have sufficient headroom for an unrestricted 2m staircase I think building control may well refuse to allow the 1.8 as that's intended for conversions where there is no other option, so do this as full plans, not a notice
Pappa Posted March 19 Author Posted March 19 Thanks for the relys. On 19/03/2025 at 08:18, ProDave said: What is your ceiling height of the room below? Expand 2760mm On 19/03/2025 at 08:55, torre said: Try a site like stairbox and play with their options. That headroom diminishing to 1.8 is the absolute minimum so don't miscalculate and then find you need 15mm for PB You already have a dormer at the back!? Then I'd definitely try to stack the stairs better. Given you already have sufficient headroom for an unrestricted 2m staircase I think building control may well refuse to allow the 1.8 as that's intended for conversions where there is no other option, so do this as full plans, not a notice Expand I got the stair dimensions from stairbox and staircreator and verified with architect. On 19/03/2025 at 08:55, torre said: Given you already have sufficient headroom for an unrestricted 2m staircase I think building control may well refuse to allow the 1.8 as that's intended for conversions where there is no other option, so do this as full plans, not a notice Expand Oh snap. I did not think of that. So I am putting in planning permission and these plans are likely to be accepted I'm told, but am I right in thinking building control do their own thing as per their interpretation of regs? So even though plans are approved, BCO could block me from proceeding with 1.8m head height?
Mr Punter Posted March 19 Posted March 19 On 19/03/2025 at 13:17, Pappa said: So even though plans are approved, BCO could block me from proceeding with 1.8m head height? Expand Yes but they try to make it so what you propose is buildable.
ProDave Posted March 19 Posted March 19 On 19/03/2025 at 13:17, Pappa said: (in answer to What is your ceiling height of the room below? ) 2760mm Expand Well you have plenty to play with, reduce the ceiling height in the rooms below to a more normal (and easier to build) 2400 and that's an additional 360mm to play with in the loft conversion which will solve all your problems of joist depth, staircase rise etc. 1
Pappa Posted March 19 Author Posted March 19 On 19/03/2025 at 16:56, ProDave said: Well you have plenty to play with, reduce the ceiling height in the rooms below to a more normal (and easier to build) 2400 and that's an additional 360mm to play with in the loft conversion which will solve all your problems of joist depth, staircase rise etc. Expand Personally, I would have liked to go lower, but I'm going to hit the windows if I go lower than this, not only do I not want to build a ramp over the windows, but there is some very ornate Victorian architraves around the windows which I'm hoping to preserve. So I'm kind of stuck at 2760mm in the rooms below. Happy to compromise elsewhere eg. expensive/awkward attic floor installation. Thanks again P
Iceverge Posted March 19 Posted March 19 On 19/03/2025 at 17:00, Pappa said: expensive/awkward attic floor installation. Expand Anything less than 170mm joists will require the floor to be built out of a mix of Unobtainum and Exoticainium and constructed by a team of F1 engineers or nano robots. Can you provide an accurate Sectional drawing of the building and I'll have a go at those stairs. You seem to be making loads of compromises based on where you want the bed and window to go. A headboard backing into a 1000mm knee wall is fine unless you like jumping on the pillows like a loon. You'd be surprised how little time people actually spend admiring the view from lying in bed. More lightly from a nice desk or chair or even the bog. 1
Gus Potter Posted March 20 Posted March 20 On 13/03/2025 at 01:24, Pappa said: Hi guys Expand Hita Pappa. I can see you have put a lot of effort into this and there is lots of good ideas getting floated. Take all these and jot them down. It's time to pay some money and get an SE in.
Pappa Posted March 21 Author Posted March 21 (edited) Good sound advice @Gus Potter and @Iceverge I don't have sectional drawings I'm afraid but I'll ask my architect to have a mess around with the stairs. My Structural Engineer is back from holiday next week so will speak to him and feed back here. At the start, you all advised me to get some joist companies to design something for me, I've had lots of quotes back at 220mm deep in I-joist and Web. Prices ranging from 1.7 to 2.7k including all fixtures. This is not far off the 1.6k material cost for 195mm deep C24 at 200 centers (which hasn't been validated by SE). So 220mm is the depth to beat as things stand. Thanks again for all your help. Edited March 21 by Pappa 1
Gus Potter Posted March 24 Posted March 24 On 21/03/2025 at 00:34, Pappa said: My Structural Engineer is back from holiday next week Expand Have a chat with your SE, hopefully folk on BH have given you some pointers about what to ask and a bit more insight. All the best.
Gus Potter Posted March 24 Posted March 24 On 16/03/2025 at 22:45, Iceverge said: where all structural engineers had been vaporised ( sorry Gus ) Expand That's ok I just hope you would turn me into a Noble Gas xxx.
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