First time poster
Got an issue with our garage, a free-standing single-brick construction double-garage specifically, with a ridged flat colourbond roof, located in Sydney.
During normal rain it's not an issue, but when it rains heavily (more water than the gutters can handle) the water rises over the back lip of the gutter and down the inside of the single brick. I'd assume it runs across the front lip as well at it's heaviest.
I've cleaned the gutters about 6 months back, and unblocked a blocked downspout (but i'll re-check when the weather clears). As above, when a normal flow of rain happens it's not an issue, just when it's excessively heavy.
From the inside, there is a wooden beam running horizontally along the top of the inside lip of the gutter, and there is a narrowing gap between the wooden beam and gutter which is no more than about 1cm wide at it's biggest.
In the past i've used expanding foam across that gap, not the best choice naturally as it's not completely waterproof, and water that spills from the rear of the gutter, and through gaps in the expanding foam run down the inside wall and allows for puddles of water to accumulate on the floor (raw concrete).
Should i remove the expanding-foam and replace with silicon? Will the silicon bind to the wood & rear lip of the gutter?
Just thought i'd seek some advice how best to waterproof the gap and stop water ingress to the inside of the garage before a more serious problem forms.
Appreciate any help or advice.