Hi
Jackson minitures do a very good looking 'old brick' sheet - I have some bought from Jeremy at Dragon G scale. The old refers to the fact that they are not smooth but have varying depth to the bricks. The sheets are 23" x 7".
Here is a photo of the bricks with some mortar colour added , each brick is 9mm x 3.5mm
Jacksons rteccomend using a cartridge gun glue, its not cheap at about £7.00 per tube but is very good according to them. The cheapest source is Screwfix, but B& Q etc should sell it - it is called Evostik Wet Grab, and is waterproof.
I have done a review for it and will have to put it up, now the site seems to be settling down.
Yours Peter