What's happening to my bricks? All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[Boltonlass]

The bricks under my patio door look to be crumbling and I can see something in one of them! Can anyone advise what's happening, why and how I can fix this?

[stoneyboy]

Hi boltonlass
The most likely cause of the bricks breaking up is frost action on the ones below DPC level. There is little you can do about this given the proximity of the sill and the decking. You could have this strip rendered and accept it will need replacing every few years.
Regards S