Floor Joists On Load Bearing Internal Wall + Door Openings

[craig1234]

I am building a two storey extension where one of the internal walls will be load bearing with floor joists running into it. Should I be able to use a single course of 125mm blocks for the wall or is it likely to need something more substantial.
In addition, two existing windows will be taken out to make doorways - the width of these openings will not change. As there are concrete lintels already in place for the windows, are these likely to need changing or should they be ok for the doorways (assuming the normal 150mm end overlap)

 

[themiddleagedun]

100mm blocks will be upto the job for a standard ext. (carring joists or not)
As for the lintels. They shouldn't need changing assuming there 140x100's

 

[Static]

100mm blocks will be upto the job for a standard ext. (carring joists or not)
As for the lintels. They shouldn't need changing assuming there 140x100's

Unless your new roof or floor bears onto/above the lintel then you should check if they can take the additional loading and beaf them up if needs be

 

[noseall]

Internal masonry walls that carry a structural load should have a concrete foundation.

 

[craig1234]

I chopped off some of the external render to investigate the extent of the lintel and was surprised to see that it doesn't appear that the outer brickwork course is supported by a lintel - only the inner blockwork course. Was this normal practice for a 1960's house? As I intend to take out the window to make a doorway I am hoping I can keep the inner lintel and fit a concrete lintel on the outer course. Does anyone see a problem with this as I am continuing to draw up my building regs plans and this is what I intend to state on them.

 

[noseall]

I was surprised to see that it doesn't appear that the outer brickwork course is supported by a lintel - only the inner blockwork course. Was this normal practice for a 1960's house?

Fairly typical.

I am hoping I can keep the inner lintel and fit a concrete lintel on the outer course. Does anyone see a problem with this

Sounds ok.