done a lot of work for a dp company, theres plenty of work about and you can make decent money...dont carry the certificates personally so likewise i cant offer guarantees...
i think you need to approach a chemical dp company/supplier such as triton or one of the others, theres quite a few now..
they should offer you a course, should consist of surveying and installation tequniques, troubleshooting etc...
theres more to it than meets the eye when you get into it...e.g. stonework, an absolute bitch to be confident on, we used to use a system called injection mortar, bitch to install...all about injecting what is basically a rubble filled cavity and then u have to guarantee it, if it fails within say 15 years you have to put it right...gonna involve hacking off again innit, this time though you get the redecor as well..
woodworm is another part of it, spotting active/inactive, easy enough job though, just a garden sprayer vessel and a lance, remove a few floorboards etc...
then you get wet/dry rot, surveying/specifying and associated building works, usually lift the floor on a timber floor house, repair/replace the joists/joist ends/supports...deep kill the remaining with a penetrating paste...ensure adequate airflow underneath (never gets an airchange under the floor else...)
tanking for below ground internal, needs to be done correctly, 3 coats, or it will fail...french drain external if ground level too high
further to this you get the basement waterproofing systems, company calls it platon or something like that, basically stiff plastic sheets u fix to the floor and wall, got like bubbles on it which key render/bonding/whatever... stick a sump pump in the bottom to shift the water collecting around the system...
external basement/belowground waterproofing...another type of membrane again...lets water drain down to the subsoil whilst keeping the wall dry...
lots of new injection systems on the market now too, pretty much makes the old pump and lances obsolete, bit like a gel u inject into the drilled holes (in the perp or joint now though), this reacts with the water in the structure/fabric to forrm your barrier, clever stuff and dead easy to do...
then you got floor/chemical membranes, theres this stuff that comes as a two part mix up, trimol (the triton version), 2 coats - base and top, make sure you get every tiny little dip though, use a small gloss roller if need be... not cheap stuff but it sets like hard perspex or even glass, very hard, i know cos i over did it once and instead of drying clear it dried a milky white, had to attack it with a grinder and it took forever....very good stuff though, works a treat...bollox to sythaproof..
got to do the fillet edges though where renders been to floor bridging the damp, then floor topping installed...leaves bout a 3/4 gap...2:1 sand/cement mix with sbr usually gets it...
big subject, lots of science, but well worth gettin into if you wanna pay the money, if your gonna go for it, might as well do it poperly..
at one time we were gettin paid silly money just for injectin...like £15 a metre linear one side only...imagine what you can charge...
somethings arnt even damp, just condensation, stick a passivent in and move the bloody wardrobe...couple of hundred quid ta very much
even been out to fix 'damp' walls over windows only to find the windows used to be box sash, are now upvc, the cill is 180, the window sits in the cavity, the cill tips back and all the rainwater runs off the end of the cill, into the cavity, straight down and out of the head of the downstairs window...no cavity trays....seen a similar thing happen with badly pointed verges and coping stones on parapet roofs...
like i said, big subject, and not all is always as it seems...