New window question

[chrismeasures1]

Hi people

I am going to fit a new window to the external wall upstairs, I am pretty confident at DIY and have had the Building regs man out so al isl in order, but have two questions for advise.

Firstly the lintel;

The opening is 1000mm across (for an inner and outer wall, cavity in the middle) I know i need to go 150mm each side with the lintel, but what kind of lintel do I use? Travis Perkins have plenty of concrete lintels in the yard, will these be good enough or do i need a steel one. I plan to pack it out with slate and set it with mortar is this right?

Secondly;

The making good of the hole, once the window is set and fixed onto the outer wall i am going to be left with the cavity and the inner wall, what is best to cover this? Is it a good idea to line the entire opening with say a 25mm thisck plank of wood, then secure the window to this, then plasterboard the inside. Or better to fix the window directly to the brick then pack out the cavity then make good.

I now it is a pretty simple job but any advise would be very much appreciated.

Many thanks

Chris

 

[chrismeasures1]

Anyone with any advise???

 

[handyman77]

You seem to have a good idea of what you need to do! For the lintel it would probably be 180mm wide 70mm thick or 2x 90x70 would be easier. The mortar you use should be a dry mix, just wet enough to bind it. Add 1 part sharp sand to it.
Personally I would fix th window directly to the brick. Pasterboard over the cavity and fit a sill.