Weatherproof / pvc frame between wall and sunroom

[t3rm3y]

Hey all,
We have a simple sunroom to replace an old timber outbuilding. It's attached to the wall currently, the new sunroom is slightly smaller, what can we add in between the wall and sunroom to extend it out about 20cm and remain waterproof and not allow any leaks.

 

[23vc]

Are you talking about an opening in an existing house wall which is going to be too big for a conservatory which is going to replace an existing wooden structure? Sketch may help.

 

[t3rm3y]

Hi 23vc, we have a external wooden lean to at the door house backdoor enters this lean to, that has its own door to get outside, we are replacing it with a new sunroom type lean-to, so will go on existing concrete.

As it's a little smaller we wanted to put a simple weather proof frame up against house wall, ideally around 20cm depth, and then mount the sunroom to this to give the same depth from house in the lean to as currently have.