Over time the surface of concrete block paving can fade and turn dull, stain from spillages and grime, and attract moss and weeds, but it is possible to clean the surface and restore it, almost to its original condition.
Cleaning and sealing block paving can be a DIY job but the strongest cleaning and sealing materials are only available to professional contractors.
Tools are available at most DIY stores which make removing moss and weeds from between the joints in block paving much easier and depending on location and aspect, this may need to be done once or twice a year.
There are also many proprietary products for cleaning and sealing block paving and although this can be a DIY project, there are a number of contractors who will be happy carry out the job for you.
As with all DIY jobs though, it will obviously cost more to pay a specialist to cleaning and sealing block paving driveways or patios but the upside is that they should have the proper tools for the job and often have access to more effective cleaning and sealing solutions. They should also take less time to do the job and save you from back ache in the meantime.