This seems to be fairly typical of private landlords - anything to save a buck. My DD's last landlord would never call in a professional to do a job that he could bodge himself. The upstairs flat had a badly fitted bath/shower and it would periodically leak through my DD's kitchen ceiling. Her landlord would go up and slap a bit of mastic round the bath and bodge the damaged ceiling downstairs. A week later it would happen again.
Her bathroom was a damp mess, always going black with mould. He told her it was her fault because she didn't ventilate the room enough. Well, she never closed the door, even when showering (she lived alone), and she never closed the window, even in winter. One of his 'solutions', when redecorating the bathroom, was to grout the tiles with waterproof silicone mastic sealant, which had the effect of trapping the penetrating damp behind the tiles, which then started to lift off
(he never considered dealing with the penetrating damp problem).