We bought a house in December and have noticed that when it rains we get a really bad smell in the house (coming from the down stairs toilet). It is a 'methane' type of smell that fills the whole house. We have had the CCTV people in (££££££), they found nothing. We had 2 different plumbers in (£££££), they didn't know what it was. We are getting to the end of our tether (excuse the spelling). Also in the bedroom above the toilet we have a 'curry' smell in the cupboard.
Any help is greatly appreciated.