advice needed on cutting simple hole for window

[jonaathan]

im planning on cutting a hole in a concrete block wall and have a few questions if anyone is able to give me a bit of advice that would be brill,

we have a simple office inside our industrial unit thats about 2.4m high, and we would like to put a window in one of the walls, the office has a flat roof which is boarded and can be walked on top off but there is nothing on top at the moment,

the wall is :
made of standard concrete blocks
internal (in our factory unit)
single skin 100mm
only rendered on one side

my question is, once i have taken the row of blocks out to put the lintel in do i just use 2 courses of bricks above the lintel (see red area in attached pic) or can i just use my grinder to cut down some concrete blocks? third option can i use thermalite blocks instead?

the main reason im asking is because after i'm finished i will need to render the are of wall on one side where the new lintel and bricks are to and i dont think the render will stick to hard engineering bricks



I have acros and strong boys and the wall is not supporting anything

cheers
jon

 

[baileysufc]

Hi john do you already have the window ? If not get one made so it fits with out cuts

with cuts personaly id just use the blocks from the hole u created

 

[jonaathan]

another question
can I just cut the space for the lintel to go in and not cut out the full block as ive got a petrol cutter

 

[baileysufc]

Yes you can do that if you wish ive done it before just becareful not to disurb things if it was me id screw a length of wood to it to give u a edge to cut down il asume ur useing a precast lintel if so leave a decent gap to bed the top of the lintel

 

[^woody^]

If you buy a "L" shaped steel lintel, you can just cut out a bed joint and slide the lintel in without disturbing the blocks above.

Otherwise, you can do either of what you mentioned.