Touring tyres

[albion]

There was an assumption that you had 20mm tyres.

The answer is probably yes though some say 28mm is maximum.
That and the 20 mentioned was why I suggested thinking about those 5mm thick Soma Everwears

 

[HLaB]

Ok cheers, so to clarify, my 700 x 20 rims should be able to take widths of 25 or even 32 mm tyres?

Its dependent on your internal rim width, Sheldon Brown done quite a good piece on it the Table at the bottom sums it up quickly, although he does admit his figures are on the cautious side. If your 20mm tyres were fitted according to his chart, you have 13mm rims and the widest you can go (a belts and braces approach) is 25mm tyres.