How to get it right: Too much abutment flashing?

This roof/chimney abutment flashing has been chased into a rendered wall to form a straight edge. It’s acting as a soaker because the lead runs under the roof tile, but water can penetrate when rainwater runs down the wall behind the flashing and through capillary action via the poorly fitted overlaps.

How to get flashing right

A better way of forming the junction would have been to have the roof tiles closer to the abutment, with each soaker around the same length as the slate and fitted over the tile beneath it to prevent the tile fixings from puncturing the soaker beneath it.

A stepped, cover flashing or secret gutter should have then been dressed into the masonry and rolled at a maximum length of 1.5m for a minimum code 4 lead (depending on location) laid over the line of soakers to direct rainwater down the roof into the guttering.

More information on this can be found on the Lead Sheet Association pocket guide.

Also read: How to install gutters.

Please Note: Every care was taken to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the dutyholder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.