We have always had a few surface cracks in the cast concrete sill of a large bay window.
Previously I have applied a surface fill of a flexible filler and painted which has lasted a few years.
Recently the filler has parted from the edges of the concrete and heavy rain finds its way to the inside wall so I am looking for a better solution.
The widest point of any of the cracks is about 2mm. I'm thinking of scraping out the cracks and trying to get some sort of mastic deep inside. (can you still buy mastic?)
What would the proffessionals use
Previously I have applied a surface fill of a flexible filler and painted which has lasted a few years.
Recently the filler has parted from the edges of the concrete and heavy rain finds its way to the inside wall so I am looking for a better solution.
The widest point of any of the cracks is about 2mm. I'm thinking of scraping out the cracks and trying to get some sort of mastic deep inside. (can you still buy mastic?)
What would the proffessionals use
