replacing windows into no cavity semi.

[robsan77]

the 1930s semi house has timber lintels across the internal skin but vertical header bricks on the external. the current windows have a timber frame but steel framing the panes.

If I replace these with upvc, how can I support the header bricks? I can pin them with props but i am guessing i need some kind of steel in place before installing the window.
Because there is no cavity Iam not sure what to use or what the best method is. Can someone help please?

Thanks

 

[robsan77]

after a little research i believe the term is stretchers, as the bricks are full length verticle.

 

[robsan77]

Ok, how about this for a plan. Please tell me if this is a bad idea.

I can use 2 acros with strong boys to prop the outside skin (2inches available) from the inside.

Once the window is out and internal plaster knocked back I will prop the timber lintel and remove the 150mm bearing either side on the internal skin and cut into the external skin enough to slide a 3 x 1 angled steel under the external skin and up between the headers and timber lintel.

I should only need knock out 1 inch in height from the external skin so i was going to make it good with a slate sandwiched in mortar for the steel to sit on. I can cut the slate to the exact size.