Damp patch on kitchen wall what can I do? I have two soaked patches on my kitchen wall the firm who...

I have two soaked patches on my kitchen wall the firm who put the DPC surrounded by 10 years ago is no longer in business and the firms I phoned adjectives want lb80 or so call out fees simply to tell me what type of soaking it is. A builder looked at it and said it was a small branch of the old DPC that have failed and desires re doing. Can I do it myself or does anyone know a firm who will just come and do it short such huge call out fees. Manchester nouns.
Answers:    1. check that your gutters aren't blocked or overflowing.
2. check the outside of the wall by running your hand over it. Is that drizzly (not just damp)
3. Are in that any cracked bricks or is there any broken mortar on the outside of that wall? If so re-point the wall or the shabby area.
4. Check your humidity course to see that earth etc hasn't built up above the horizontal of the damp course. Clear it if obligatory
5.Check there is nought leaning against the outside wall that might be letting marine breach the damp course. Move anything.
6. If there is no problem near the outside of the wall get a dehumidifier. I may give somebody a lift months to clear a really damp wall beside a domestic dehumidifier.
7. Lastly, I presume the damp nouns isn't under a flat roof? If so, clear any dampen that might have gather on the flat roof and get it checked. You may necessitate to resurface it
Paint over it and sell the house spur-of-the-moment