OT - building construction

[MarkieB]

apologies for the OT, only that you lot have seemed quite knowledgeable for this kind of question before

now, you see, we've got a landing that belongs to us

before making it part of the flat, the objective would be to enlarge it — looking at it, it would turn a kind of cramped hallway into a decent sized room

1 a sketch of it as it is now

2 a sketch of it as it should be enlarged [there's headroom in the stairwell to do so]

3 a possible idea of putting a joist across from the wall to the staircase woodwork [seems very solid]

is the joist idea workable? what should I then put in to connect the joist to the new floor above?

French Building regulations are not binding, so there are no worries there, save that it'd be good to know what eg UK Building regulations say, as they are generally quite sensible

cheers

Mark

[s2hotdog]

apologies for the OT, only that you lot have seemed quite knowledgeable for this kind of question before

now, you see, we've got a landing that belongs to us

before making it part of the flat, the objective would be to enlarge it — looking at it, it would turn a kind of cramped hallway into a decent sized room

1 a sketch of it as it is now

2 a sketch of it as it should be enlarged [there's headroom in the stairwell to do so]

3 a possible idea of putting a joist across from the wall to the staircase woodwork [seems very solid]

is the joist idea workable? what should I then put in to connect the joist to the new floor above?

French Building regulations are not binding, so there are no worries there, save that it'd be good to know what eg UK Building regulations say, as they are generally quite sensible

cheers

Mark

Hi

Its diifficult to understand without seeing the building - but its not a good idea to support a structure off a stairs if possible have a column in the corner adjacent to the stairs with a support beam above back to the wall

But as noted its difficult to understand without seeing it

HTH

Steve

[bishbosh]

^^^^^^^^^^^^Wot he said^^^^^^^^^^^^^

very difficult to understand what you are trying to achieve.

I would suggest doing three sketches for us - One before, one after with key dinensions and a third showing where the structural members are currently.

[SOA 93]

I understand what you are trying to do, I assume the wall opposite the stairs is load bearing its just the other side adjacent to the stair that has nothing to support it, hence the beam underneath. Building regs in the UK change a lot more frequently these days but IIRC headroom in a stair well should be 2m vertical from the tread nose of the stairs, if that makes sense to you.

I don't think you should be putting additional load on the stair string if they are wooden, even if they are solid.

You show 4 steps, is this the last 4 of a flight or do they lead to a landing?

If you could get that lower beam under the stair string and onto the stair wall and still retain headroom under the stairs then its easy from there.

How far is the new landing coming out?

Hope some of that makes sense.

Andy

[MarkieB]

the sketches attached to the first post are in the numbered order; the side walls [showing in dark grey] are both load-bearing walls, dimensions are

current landing is 170cm deep, 270cm wide

stairs are 110cm wide

enlargement would be ~70cm distance, 160cm wide

height from base of joist to floor level ~65cm

there are 6"+ solid old [1850's] wooden beams [green striped] between the load-bearing walls at the top of the stairs, + at the next landing down, that the staircase [structural in dotted green] is attached to

Andy, that does make sense; I've just sketched the first few stairs, they lead to another landing; what you say sounds sensible I should put the joist the whole way across, only as you rightly say, I have to retain the headroom; I can't put the joist under the stair string, I'd have to interrupt the stairway; a bit more of a task than I'd really care to tackle

I'm not sure I understand the idea with the column + support beam, Steve, is it what I've sketched in blue — would I need the joist either way?

cheers

Mark

[SOA 93]

I should forget about connecting into your stair string.

The pillar woud need to come from something load bearing underneath.

The lower beam does not have to be directly under your stud wall you could cantilever it a little, and put some diagonal strutes in.

Could do with a side elevation showing the bottom of the stair strings, head room, thickness of floor etc.

More complicated/expensive is to put a beam across above head height and then drop a column down to pick-up the end of your joist.

In the uk lots of people have a bedroom over the stairs and many have a large box directly above the stairwell at low level, you could do some thing similar and have the lower section of your wall sloping out, before going vertical.

Andy

[s2hotdog]

Mark

The main support beam is to be at 90 degrees to the way you have drawn it and post is to go down to floor level if possible

But as stated really need to see to understand

Steve

[MarkieB]

More complicated/expensive is to put a beam across above head height and then drop a column down to pick-up the end of your joist.

that I think is what I'll have to do; would you say the beam could be one of the original wooden ceiling beams [very solid] or should I try to put in a new metal beam [a bit beyond me as the load-bearing walls have got a window [one way] / a chimney [t'other] that make them less strong.]

cheers

[SOA 93]

that I think is what I'll have to do; would you say the beam could be one of the original wooden ceiling beams [very solid] or should I try to put in a new metal beam [a bit beyond me as the load-bearing walls have got a window [one way] / a chimney [t'other] that make them less strong.]

cheers

Depends where the window is, you don't want the new beam directly over the window unless you have a fair bit of brickwork above the window, off the top of my head I'd say 50% of its width, to the side of the window is ok. On the chimney side, you are not supposed to put a beam into a chimney for obvious reasons.

You have a PM

[MarkieB]

Thanks Andy, you've been very helpful

cheers

Mark