"gap between the house and the pergola guttering."
Hi Adam - we had a somewhat similar problem a long time ago and for us the only solution was to reposition the pergola roof above the roof line.
Achieved with 'homemade' brackets...
Thank you for posting those photos. Let's talk about some of the symptoms of this type of setup. Are you getting dribbles of water coming down the wall or is it just the occasional water splash? Is the roof overflowing into the Gazebos gutter? In these instances, we can try some standard troubleshooting steps.
If it is just splash-related wetness and not a water overflow issue you can cover the gap from the top with a Galvanized window flashing. I've placed a diagram below for you to see.
If you have any questions, please let us know.
Thanks for an excellent image there @EricL, just what I had in mind when I mentioned flashing earlier. Just looking and the style you'd want is technically apron rather than angle. You can have these custome made in a size to suit.
As @Noyade pointed out the ideal structure for such a situation is for the additional roof to be above, not below the existing roofline but that then poses it's own issues as you generally have roof mounting involved etc.
There's also an excellent bitumen impregnated foam expansion tape that is fantastic for waterproofing such situations, I've used it to fix a roof valley gutter leak. Can't find it on-line but if I can I'll link to it for you.
"Perhaps the gutter needs a clean?"
Never thought of that simple solution.
Well played Eric!
We can order custom made angles using the clock method from Fielders. Their type 44 or the angle I've put together on the right could be suitable.
The bitumen impregnated foam is Compriband from Ormonoid. I know Abelflex, which is just the foam, has a sticky back version. I'm not sure whether Ormonoid makes a sticky back bitumen impregnated one, or perhaps it's a different supplier. It sounds like the bee's knees though and would be ideal if you can compress it between the guttering/flashing and the wall.
That's very handy to know re the flashing @MitchellMc , thank you.
And Compriband, that's the stuff. Fantastically useful in situations where you can compress it to create a seal.
Great thing about this site is learning and seeing products I've not seen or heard of before.