Lintel needs to be repaired or extra support added - advice is needed!!!

[Angela89]

hello guys!
recently I have bought a house which required a dinning\kitchen area to be refurbished
kitchen is an extension built in the end of terraced house (yr 188? )
some time ago one of the previous owners made an opening in a back external cavity wall and connected dinning room with a kitchen

the width of this opening is 200cm
there are two concrete lintels for each side of this wall supported by something like 12-15cm of brick
(please check sketch below)
lintels are 65x102mm with length about 2400mm

there is just one room above the dinning room and slope roof above the kitchen room

everything was nicely covered with ceiling and plasterboard cut arch in this opening

luckily as a part of refurbishment I have removed them and found that original outside wall lintel is actually bent a little and the brickwork above it is a bit loose - "thanks" to another stupidest person who rammed the wall with a hammer to insert rafters for a flat kitchen ceiling

so these 65x102mm lintels are actually helping to hold a brick wall (was original external wall of the building), the wall in question is around 2m high on one side and something like 4m at the other side (~3m tall wall on average - second sketch)

THE QUESTION

I want to create additional support for these lintels by adding another one right below (third sketch)

I have plenty of space to extend walls into opening to create 100-150mm of support and there is up to 200mm in height to sacrifice before this opening will look too low

* Should I go for reinforced concrete or RSJ?
* My idea is to jack up two RSJs (one for each "layer" of this cavity wall) with some mortar using props, build a brick sides-supports, leave everything dry and set, then fill remaining gap between bricks-RSJs and remove props, maybe it will be a good idea to put some steel anchors through new brickwork and original wall for extra rigidity

Any suggestions how to do it more than welcome!

THANK YOU!

p.s. I will try to find some real-world pics in a second

 

[Angela89]

ah... only rubbish pictures on this computer, here they are:

- overview of this wall\location from kitchen-into-dinning room (sorry for fisheye lens)
- closeup of lintels currently in place

thank you!

 

[Angela89]

or maybe one of those modern lintels will be ok?
http://catnic.com/products/cx150-100
it will also save a lot of space

 

[mfarrow]

What is the purpose of replacing/reinforcing the lintels? Why are you convinced the whole lot will come down? If it's been like that for 20 years plus I would not be concerned, unless you're planning a Living space upstairs, in which case a new lintel may be a good option.

 

[Angela89]

my concerns are:

- one of the lintels is visibly bent (never actually measured the exact figure)
- someone was bright enough to nail the arch (not shown in pictures, removed already) to the lintels itself
- it is so easy and inexpensive to make this opening even stronger, actually If regular reinforced concrete bars would be "enough" I would go to 140x100mm concrete lintels, install them with some tension underneath the existing lintels and support them with extended wall,
just for peace of mind, if these lintels were originally 140mm I would not do anything but they are 65mm

with allocated budged of three fuel tanks for my car I see no reason why not to do it today and sleep really well at night

the main question is - should I use regular reinforced concrete lintel (let me say 140x100mm~ in size) or go hardcore and choose RSJ or maybe steel box ?

thank you!

 

[Angela89]

rough estimation - it is ~10mm down in the middle for 2000mm length

 

[Angela89]

few holes from nails

 

[Angela89]

what is above this lintel