Composite Doors (Door with Attached Half Height Window)

[BD26]

Hello all first post on forum.

Please see attached for reference. These doors get used everywhere in the UK and I was wondering how they can be justified to work structurally apart from the usual response of "we have used these everywhere".

This situation may arise in timber frame construction or load bearing masonry, the portion of wall below window has no head restraint so must this wall be designed as cantilevering from the base with lateral wind load from window taken at tip? This would result in moment connection being required at base of timber studs (if timber stud construction).

This isn't for a job I am currently working on just now it is just something I have picked up on and wondered what other engineers thought were on this.

 

[KootK]

"we have used these everywhere".

Mostly that no doubt.

For a masonry wall, I think you could rely on some horizontal cantilevering to pick up the naughty bit. Of course, that kind of requires a back span. In your photo, there's back-span on one side but not really the other unless you're taking it around the corner.

It would be a pretty tall order in wood, possibly taking one of these forms:

1) Some obnoxious strapping etc to carry the sill plate back into the wall (unlikely).

2) Tying the sill into the door jamb structure which may or may not be kosher (more likely).

Cantilevering, as you mentioned, is always an option. Just not a very attractive one.

 

[Ron247]

On a wood wall, is there possibly a full king stud between the door and window? If so, that would provide support similar to using the jamb as KootK mentioned.

For load bearing masonry, I guess the base of the short wall could be fixed to some degree.

 

[BD26]

Yes I have always thought the wall would end up taking restraint off the jamb but this seems backwards as the door/window system is normally designed to be fixed to the superstructure. There is no timber jack between door and window, just a PVC jamb.

I didn't think it could be justified to say the jamb is taking any load from the wall as this would be for the door frame manufacturer to confirm, although possibly this is something they take into account when designing their doors as the door jamb is already taking a partial UDL from the windows I would think.

 

[BUGGAR]

It works if the glazing acts as a shear panel. But we all know that glass, like tack welds, is non-structural.

 

[EdStainless]

I'll bet that these doors are easy to kick in.
Must be a lot of flex in that panel.

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P.E. Metallurgy, Plymouth Tube

 

[IRstuff]

Doors are non-structural, period, unless they happen to have been repaired a half-dozen times and the door sticks in the frame ;-). The framing above the door has to carry and transmit the load to the sections of solid wall .

If you look at the current trend in open design, where the majority of the back wall of a house has folding doors for a merged patio/family room, you'd find a steel beam carrying the load of the upper story walls down to the studs around the opening. And the studs might be steel box beams. The two-car garage in my previous house had steel around three sides of the sectional door.

TTFN (ta ta for now)
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