single door way through a cavity wall that was old gable end

[harbourside]

Hi, I have moved into a house that has had a two storey extension to one side. I would like put a single doorway through what would have been the old side of the house which is of cavity contruction so that I can create a new ensuite area to the bedroom. My Qs are:
- can I put a concrete or steel lintel into each skin or do I need to put a single lintel that supports both cavities?
- what type of lintel is best for this type of application? Would I need a catnic and if so how would I insert in the space?
- I was hoping to cut out a space sufficient to take the lintel (inc 150mm either side for support) above the finished height of the door liner on one side of the cavity, bed in the lintel, let it set and then remove the brick below. Repeat the process for the outer skin?
- the old gable end will be above the area where I would like to cut the new doorway into.

thanks for your help

 

[noseall]

In about 95% of first floor, standard doorway sized knock-outs, a pair of concrete 75mm x 100mm p.c.c. (pre-cast concrete) lintels will do the job.

One (individual) concrete lintel for each leaf of masonry

 

[harbourside]

not sure how to use this forum yet - thanks noseall - would i need to support the wall in anyway joists are running paralell to the gable end or could i just cut out

 

[harbourside]

In about 95% of first floor, standard doorway sized knock-outs, a pair of concrete 75mm x 100mm p.c.c. (pre-cast concrete) lintels will do the job.

One (individual) concrete lintel for each leaf of masonry

Would I need to support the gable in anyway, joist run parallel to the wall I am putting the doorway into, or could I just cut out? Thanks

 

[noseall]

Unlikely.

A doorway sized knockout requires about a 1.2m sized lintel slot. This would allow a very small triangle of masonry to fall should gravity or mass allow it to.

Just be sympathetic to the masonry you are removing. Brickwork is fairly stable and self arching. Blockwork can be less predictable.

Use a drill and stitch drill the opening out and stitch the lintel bearing also. By this i mean weaken your intended cut out line by drilling a lot of holes on this line with a decent drill.

 

[harbourside]

Unlikely.

A doorway sized knockout requires about a 1.2m sized lintel slot. This would allow a very small triangle of masonry to fall should gravity or mass allow it to.

Just be sympathetic to the masonry you are removing. Brickwork is fairly stable and self arching. Blockwork can be less predictable.

Use a drill and stitch drill the opening out and stitch the lintel bearing also. By this i mean weaken your intended cut out line by drilling a lot of holes on this line with a decent drill.

Thanks again makes sense - what would be the cost of doing this via a builder just so I can weigh up my options?

 

[noseall]

£250 - £700 dependant upon waste removal, making good, access etc.