Newel problem / structural support

[RichA]

I am having a staircase installed this week (!); and it is only now that it has been made clear that one of the newel posts (right side on pic below) is going to protrude into the downstairs WC.

Is there any way to cut/support the right hand newel with a post/steel?
NB There is a stud wall in between these two newel posts.

 

[RichA]

Here are some pics after day 1. The post on the right in the first 3 pics is going to intrude into the WC.

Is it possible to sister a newel to a stud, post or similar?

 

[big-all]

the only way i can see is to go up to the ceiling from the top off the newel
cant see a path from the wall at one side to the other newel that wont look carp and get in the way

 

[RichA]

Can it be sistered? i.e. bolt through the newel to a post where the red column is, and then cut the newel where the blue lines cross?

The red post is aligned with where we will be building a stud wall to enclose the WC.

 

[big-all]

do you need the full width removed ??
as in 100mm newel cut where the dotted line
where the pink is on your drawing a full width plank well attached to both newels and string face with a notch to support under the newel about 25mm giving you 75mm extra room
you may be ok without the 25mm under the newel but that relies on the support off the cut newel relying on the string to newel joint

 

[Deleted member 174758]

I'd say that those vertical "newel posts" are probably structural. Have you asked the supplier? If so you'll need to replace the strength that you remove when you cut one out. If the stud wall as made into a structural stud wall (doubled-up sole plate, doubled or trebled-up header, studs on 400mm centres, C16 timber, ideally 4 x 2s, must sit on a concrete floor or above a doubled-up joist) it should be possible to feed the load into the stud wall, although I'd have a word with the stair suppliers (to gauge the sort of loading the post will carry) and your s-e (if you have one) first

 

[RichA]

Thanks both. Newel post is structural; therefore I want to transfer the load to an additional post/the stud wall. The stud wall can be made structural.

Removing 60mm/leaving 30mm should work fine.

We could then have double studs behind the newel, and further studs beside the newel (ie form a c-shape around newel)?

 

[Deleted member 174758]

How about a structural stud wall with double sole/header plates, doubled-up studs beneath the newel and a doublked-up 4 x 2 C16 across the top of the stud wall to the other (masonry?) wall to carry the bottom of the curtailed newel post?

 

[RichA]

How about a structural stud wall with double sole/header plates, doubled-up studs beneath the newel and a doublked-up 4 x 2 C16 across the top of the stud wall to the other (masonry?) wall to carry the bottom of the curtailed newel post?

I am not sure I understand? Where would the joist run, it can't cross to the right due to head height restrictions (there is a WC going under the stairs).

I was thinking something like this???

 

[Deleted member 174758]

Sorry, didn't realise from your photos/drawing. Yes, I think that an over-width binder attached to the top of the stud wall (say a 5 x 2 or 6 x 2 atop a double 4 x 2 stud header and all bolted together) would work and could probably be configured so as to sit inside the ceiling structure of the toilet. In that instance I'd also look to beefing up the frame at the front of the toilet (where the door is) to ensure that it resisted any side pressure from the longer stud wall.

I have to admit that I'm not one for taking too many risks on structures such as this - over-engineering rarely results in failures in my experience

 

[RichA]

Happy to over-engineer. Please can you spell out in really simple terms; as I don't really understand how this would work? (Sorry)

 

[Ian H]

I think he means like this:

If you had the headheigh you could swap the 6x2 for something that goes all the way across to the wall on the left (not on the picture)

 

[Deleted member 174758]

Yes, that's it, Ian. I've done it in SketchUp in 3D also showing the doubled-up studs beneath the cut newel post and the doubled-up header on the end (door wall) which would stiffen the whole thing up. These would need to be bolted together for maximum strength. Newels are shown pink and yellow respectively in the drawing:

Someone will now tell me it's massively over-engineered and do the whole lot in 12mm thick balsa and string, I have no doubt.....

 

[RichA]

Yes, that's it, Ian. I've done it in SketchUp in 3D also showing the doubled-up studs beneath the cut newel post and the doubled-up header on the end (door wall) which would stiffen the whole thing up. These would need to be bolted together for maximum strength.

Many thanks for this I really appreciate the help. I am not sure this solves the issue as I need to remove support from under the Newel to create the width in the WC.

I was proposing something like this. Trim 2/3's off newel, and bolt through to a 'Structural' stud wall with posts behind and along side.

This would remove 60mm of protruding post (and make my WC 60mm wider). i.e. 875 v 815mm.

 

[Deleted member 174758]

Whilst it looks nice in theory, making a rip cut like that on an installed timber staircase (which is carrying a load) anywhere near neatly will prove fairly difficult to achieve in practice, especially as you are trying to rip about 2 metres of 4in thick timber vertically. Have you ever done that with a power rip saw? Or even with a hand saw? I somehow doubt it (based on the fact that I do sometimes need to do "trick" cuts like that). It will be hard work either way, not to mention potentially dangerous to do with a power rip saw. Another thing to consider is that you probably won't get the 1 metre or more overlap that a sistered element should have at the full thickness, so if a crack develops from the corner of your cut-away and propogates upwards along the grain and maybe to the outside edge of the timber it could cause the failure of that newel post. Remember, this is a staircase and AFAIK work such as this is notifiable and needs to have the approval of the BCO. TBH I doubt that I could ever fly your method past a BCO

In view of the fact that you need to build the wall in any case, I'd just have Acrow-propped the staircase up, cut the excess newel post off, built the wall, fixed the bottom of the shortened newel to the top of the frame and then removed the Acrow. This, I think would be easier and safer to do, and relatively fast if you can do basic framing.