cracked outside wall - flashing

[markjones]

There is a crack about 40 - 50 centimeters long and 1 cm wide in the rendering just above a join to the roof of my rear extension. I think it is because the roof flashing is concrete and has cracked allowing some water/cold in.

I plan to hack-off the cracked area and re-render. What mixture do I need to do this? Do I need a specialist?

Also, can I buy and easily fit a differnt flashing so the crack doesn't come back? i know lead flashing is meant to be better.

Thanks for any advice in advance.

 

[breezer]

don't know about the render mix, but lead flashing is used for its durability. we had to have our house's flashing done in leaad as the origonal zinc flashing "wore out" and developed holes allowing the rain in, our house must be at least 30 years old, so i suppose the zinc didn't do too bad