I'd like to inject some expanding foam between the corrugated asbestos sheets forming my garage roof, to prevent rainwater ingress, when the wind is blowing in the same direction as the slope of the roof. The standard expanding foam canisters have an applicator that is betqwwn 5mm and 10 mm OD. I need something that is more like 2mm! Can anyone suggest how I might achieve this? Un fortunately, it would be very difficult to pry the sheets apart whee the overlap, as they are securely nailed ti the roof joists with
6" roofing nails.Many thanks...
JD