Landing Frameless Glass Balustrade Fixing

[ultramods]

The person that is going to be fabricating our cantilevered stair was at the house today measuring up. One measurement I wasn't sure on is the extra depth required for the landing to take into account the side fixing of the glass balustrade

 

The finished stair will look similar to the photo below. I would like the glass (17.5mm laminated) to appear to be frameless so it appears to have no fixings.

 

 

I think the fixing would be similar to the drawing below. Can anyone tell me please how this fixing should be attached to the landing, can it be fixed directly to the edge/side of the posi-joist or would I need to attach say ply-wood to the edge/side of the posi-joist and then fix the glass rail onto the ply-wood?

 

Obviously fixing directly to the posi-joist would be the preferred option as I would like any extra landing depth to a minimum. 

 

This is a detail I forgot about and is needed now as the stair fabricator is working throughout the xmas period.

 

 

 

[Russell griffiths]

I would think you would need to bring out the bottom cord of the posi joist by 50mm to incorporate that 47mm wide channel then ply over the entire face and then plasterboard 

the thing you will need to pay attention to is the junction between the balcony glass and the angled piece going up the stairs, as bringing out the balcony bit will alter the size of the panes coming up the side of the stairs. 

You will need to pay attention to the quality of this work as the force exerted on the top of that glass as somebody leans on it will be fairly large. 

[Mr Punter]

Shame that last joist is not a glulam or LVL.  Are you planning on plasterboard to run up to the underside of the glazing channel?  I think with channel you will need a continuous sheet of ply as the fixing will probably only just get the bottom edge of the top chord.

 

You could look at the stand-off type fixings instead of the channel.  Are you going without handrail?  Although it looks sleek it is not comfortable, although it will mean that it does not get approached or leaned against much.

[ultramods]

What I’m thinking might ‘be the best idea is to move the outside position-joist further back towards the centre of the landing, then place a solid timber joist or plywood at the end. At this stage there shouldn’ttoo much rework required..

 

thanks for for the advice 

Edited December 24, 2018 by ultramods

[PeterW]

Existing one should be fine as that’s a 47mm top chord with a 22mm board, putting the coach screw (or bolt..?) in the middle of the top chord. 

 

If you glue and screw 12mm ply across the front of the joist to give a flat surface for the channel to fit to, it will be fine. The rotational force will snap the glass before it pulls the coach screw out of the timber. 

 

 

[Mr Punter]

The chords look a bit thin for the 12mm fixings to get a good bite and some of them will probably hit the metal web.  Because the whole of the channel would need to fail, you would notice that the glazing seemed loose before it became critical.

 

In this location you are not likely to get a large number of people squashed up to the glass in the way you might if this was a balcony, but you need to consider the risk if, say, a future owner lets this as an AirBnB to a stag party.