Hi all, I am currently renovating our kitchen, and as part of this I want to install a cooker hood with an external vent. The cooker will be located on an external wall, which should hopefully make running it to outside a fairly easy DIY job. The problem is that there is a lean-to immediately behind this wall (very basic construction with corrugated plastic roof, currently not used for anything other than storage). The hood shaft will be above the lean-to, but I will likely be looking at less than a foot between the top of the lean-to and the exit for the vent. Is this likely to cause any problems, for example grease build up on top of the lean-to? Is there a better way to do this? Thanks all, have a good Easter!