I am finding with my BCO, if it can be certified as OK (such as by tile manufacturers etc), he will accept it otherwise not. He has not said "NO" to anything, but I get the hint from his tone, such as when I suggested dual layer of roof underlay to allow lower pitch. Of course a manufacturer will not guarantee something like this since they cannot test it, so I'm stuck ! How can I get him to accept DIY solutions without official tests etc ? I need to have a cowl terminal through my roof. OK, 4" pipe, weathering slate (expensive, price of lead etc), cowl terminal, overall cost over 50 quid. Why not drill a hole in the tile, glue in a cowl terminal (suitable flexible glue to allow for expansion etc), and jobs a good'un. How could I persuade the BCO to accept this or other DIY solutions ? I cannot just do it afterwards, as the kitchen must have extract to gain approval.
Simon.