Damp on Brick Wall in Conservatory after Replacing Roof with Light Weight Plastic Tiles

[Danny1]

I recently replaced my conservatory roof with a light weight plastic tile roof but noticed recently the brick wall is very damp about 1 Sqm and with heavy rain it runs down the wall . I was advised on how to do the roof with osb3 sheets and roof lining which runs up the wall about 5 inches then tiles ,but the flashing I used flashband with Primer and fixed it with galvanised strips with sealant ,also I had the corner wall bricks relayed as about 30 were loose ,not the best job .can anyone help thanks

[Danny1]

Forgot to mention the other side of the wall is boarded and rendered but have had a look and no visible cracks in the render