Help please. I got a new roof fitted to the extension of my house two years ago. The roof is slanted from the roof of the main house which is a hip roof. on the side of the extension wall is a boilerhouse attached. Water has been coming off the new roof on to the boilerhouse causing dampness in the boilerhouse and now this wet has seeped into my dining from. The builder did not put lead flashing on the boilerhouse roof where it meets the extension wall at the time he fitted the new roof. I now have external insulation on the walls of the house so I cant use lead flashing. I wonder if alluminiam soakers could be used for flashing.
My builder has suggested putting felt on the boilerhouse roof and suggests it is the boilerhouse roof is the cause of the damage not the water coming from new roof. Until i got new roof I had no problem with the boilerhouse or dining room.
I would be grateful for advice .