NY wrote:

"The Natural Philosopher" wrote in message
...
Change the door to a big up and over.

I may have to do that, but that means some mind of structural
strengthening of the lintel

May just knock it down and put in something else

This is the crux of the problem. How does a builder remove two short
lintels/RSJs and the brick pillar between the two narrow doors which is
supporting one end of each lintel, and install a longer lintel which is
supported only at each end and not in the middle, while continuing to
support the courses of bricks above the lintels?

I realise that you use acroprops to provide temporary support while the
short lintel is replaced by the full one, but you need to slide out one end
of the lintel and then get the acroprop in before the courses of bricks
above start to "bend" into the gap. Rinse and repeat all the way along as
the old lintels are gradually removed, and then reverse the process as the
new lintel is inserted in their place.

I meant to watch the builders who did this when they inserted a new doorway
into the brick/breezeblock wall of our house, but I forgot, and by the time
I remembered, they'd already done it.

You need props with shortish, thin cantilevers to load bear off the axis
of the prop and go between the lintel and the masonry above.
--

Roger Hayter