Have sent you email.

Posted By: fostertomIsn't Bldg Regs sufficient?

That refers to BS5395 in places.

Consider pushing the bed up there before installing the stairscase :-)

Posted By: jonharrispart K building regs but it's very vague on spiral/helical stairs and basically tells you to follow BS 5395. The good thing about this is that the BS guidelines on spirals are far more accommodating

Really? Give some idea of how? The only way I can think of, that the BS could be more relaxed than PtK, is if it allows less than 50 minimum going. You can do some already excessively tight, perilous-feeling designs under PtK.

definition is based on how the structure is formed
spiral stairs are connected to a central 'pillar'
helical stairs are the structure and will 'spiral' to their own design.

see image gallery below
http://www.crescentstairs.co.uk/image-gallery.php
tech spec for cat a may be useful
http://www.crescentstairs.co.uk/technical-specifications.php

4 sides of an octagon is a double winder isnt it
http://www.stairplan.com/winderstaircases.htm#double
you could maybe do the same as above but with 2no. 4 tread winders rather than 3 tread.

It's a shame I cant easily knock up a demo so I can get a taste of what it's like to climb a helical with a 150mm centre going (235mm outside, 120mm inside), 220 rise, with 600mm width steps. BS 5395 would allow it. It's on the limit, but it's still feasible, and I'm seriously looking at using it. I agree, there may be a chance it'll be a little precarious to navigate. However, I propose a central handrail and walls flush to the outside string to offer at least a reasonable level of protection from falling.

As for loft ladders serving a 3rd floor loft conversion in a period house? I just don't think that would look right to be honest - and my wife hates climbing ladders! If we ever decided to sell then I'd imagine it'd put off a fair few buyers too. There's no reason why compact stairs cant be aesthetic and functional. When I get a moment, I'll try and upload a plan of my design so you guys can critique it.

I have looked at the dogleg with winders, but it renders it part K and so I'm stuck with the 220 going. I did manage to pull together a design with that, although it ate up quite a bit of space and compromised one of my 1st floor bedrooms (bed 3) rather more than I would have liked.

I also looked hard at building stairs over existing stairs. Unfortunately, to give the head height I'd need a _large_ side dormer. Not a big fan of those for reasons I've mentioned before about unbalancing the roof lines as we live in a semi-d.

Here is a rough plan of my 180 degree helical. Bedroom 3 will be compromised, but bespoke stairs fitted in situ will allow for storage under, and with 9 steps up before hitting bedroom 1, I should be able to open the door without obstruction, with the final 3 steps sited over the entrance. Bedroom 2 is unaffected by the design.

12 steps total with a 220 rise will get me up to 2800mm and in the loft. The position of the last step is critical because it sites me in the ideal spot for a small 3rd floor landing and access door to bedroom 4.

Handrail to go on the inside. Step width 600, total diameter 1800.

Here are some rough before and after plans. Any thoughts? Also would this design pass as helical?

Looks neat - and makes sense, if the ridge runs bottom to top. If left to right, don't see why this is OK for headroom but a stair over stairwell requires dormer. Top floor plan? - is it 2 rooms or one up there?

Posted By: fostertomLooks neat - and makes sense, if the ridge runs bottom to top. If left to right, don't see why this is OK for headroom but a stair over stairwell requires dormer. Top floor plan? - is it 2 rooms or one up there?

Thanks. Here is the top level plan with lines to show the structure of the hipped roof. Just 1 bedroom. Not sure if I can squeeze a WC in, probably not, but I've shown where it could go, if there was enough head room. I suppose if you sit down to use the loo, it might just be possible?

Posted By: ali.gillUnless you're planning on a big chunky pillar in the middle of the half doughnut then that is a helical staircase.
post the dims for the inner and outer half octagon and i might stay up late and knock up a 3d model.
might as well add the height of the door for bed 1 and ceiling.

No central pillar intended. Thanks for confirmation on the design. 3d model would be very, very cool and much appreciated!

Octagon is 1800mm outside dia, inside dia is 600mm. Height of door is 2000mm and ceiling is 2650mm.

First floor plan is zoomed in a bit, cropping off much of bedrooms 1, 2 and 3. Might explain the staircase appearing to shift between floors, although I admit these are rough drafts done by hand without measuring.

Trouble with starting stairs above stairwell is that the thick 10" purlins get in the way of headroom. They are sited roughly where the walls are on the top floor. I've been told you can pull them out and put in purlin walls but wont these still cause an obstruction if the stairs start to climb right up against the outside wall?

Dormer on side is certainly a possibility. Would need to be built off the outside wall and rise up to ridge height (or very near), to give the headroom. So it wont be small! I guess you could give the dormer a hipped roof to soften the view from the main road, but it's still not my preferred option.

Good idea about using the velux to steal extra headroom. I did think of this before, and it _might_ just give me enough scope to run the stairs in the way you suggest. However, would it not mean I'll need a very long sheet of glass running the full length of the roof hip and directly above the stairs, approx 2.5 - 3m long, and about 600mm wide? From the main road it might look a bit odd.

Here is a complete 1st floor plan. Straight flight of stairs from ground to 1st floor, with half landing at top.

Purlin is about 1.5m in from end wall. Roof pitch approx 45 degrees.

Another useful measurement is the 1st floor ground to purlin height which is 3.4m.

Oo I see jonharris - looks like your solution's prob right, v neat in fact.

Posted By: fostertomOo I see jonharris - looks like your solution's prob right, v neat in fact.

Thanks Tom, high praise coming from an Architect!

No doubt you spotted the need to run the stairs in the top left corner of the purlins to maximise space on the top floor?

The stairs look scary - even in a virtual world.
Its a sketchup file - so download the free version of sketchup -
I'll post the .skp file up to the google warehouse so you can download it from there and will update you on its name when its up. apparently gw doesnt like firefox.
*edit - what a crock of shit - you'll have to whisper your email address until i can sort out getting it uploaded.
download it, open it up, right click where it says plan and select 'play animation'
click Window - Outliner : to see the three components copied four times.
i suppose we could add a foot or two to see how much you actually get to step on!

Can you drop a plumb line from the purlin then get a measurement from the first floor external wall (above stairway) parallel as possible with the wall to bedroom 3. get a photo of what part of the purlin the plumbline is hung from, and purlin dims.

Tom, you got me thinking about going for a pair of small Velux's now, side by side. One serving the loft landing and other the WC, placed right above the pan for extra head height. Obscure glass for obvious reasons! I've calculated it could give me as much as an extra 10 or 12 inches vertical headroom, by the time I've factored in all the insulation I'll have to fit, both in and over the rafters. Would need to shift the bedroom door over a little to make room for cloakroom door alongside, which would be accessed via bedroom and probably needing a sizeable corner cutting off to fit.

Thanks for those renders ali.gill, much appreciated. The first one looks dangerously steep, possibly due to the strong perspective applied? The second one looks a bit kinder. I think seeing it with walls/strings and a handrail would definitely help, if you can spare the time. My email address is on my profile. So far I like what I see. It's certainly steep, but at the same time quite exciting and a little unusual... it's certainly not put me off. Maybe the view from the top looking down might do though!

Posted By: ali.gillCan you drop a plumb line from the purlin then get a measurement from the first floor external wall (above stairway) parallel as possible with the wall to bedroom 3. get a photo of what part of the purlin the plumbline is hung from, and purlin dims.

Distance from lowest point on purlin to end wall is 1250mm. I used a plumb line as you said. Purlins are 9"x3". Photo attached with arrow pointing to where I measured from. Got lots more pics and measurements if you need them, as I've been up the loft today and written them all down.