Bad drain smell in bathroom

We have just taken ownership in block 276 and found that on a daily basis around 1pm - 7pm we are getting a really bad smell of drains in the bathroom. Seems to be when the sun is at it's highest. It is not there overnight or in the mornings. We have cleaned out any traps that we can open and put drain cleaner down the basin and bath plugs but this has not resolved the issue. Sticking your nose close to the plugholes doesn't give any obvious indication that the smell is coming from there either. While sitting on the balcony during these time there is the odd occation that you get the same smell here very briefly.

We have noticed that the pipe leading out of the basin has an L shaped outlet instead of the normal U bend we have in the UK but without knowing what pipework is in the wall we can't tell if this is correct or not.

Has anyone had this problem and is there any advice on resolving this? 

Regards

P & P

The sinks, bath, bidet and toilet all have water traps to stop the smell coming up from the drains. Having said that, the water could evaporate if not used for an extended period. I guess you have tried flushing all your fixtures?

It is more likely to be coming either from an outside drain or from the vents from the downpipe on the roof. The latter sounds more likely as you are getting a stronger smell inside. Have you been on the roof? Is the smell bad there? If so, might be a blocked downpipe from someone flushing something they shouldn't.

As an aside, this forum is infrequently visited, The main forum is the Terrazas de La Torre Golf Resort forum.

Thank Duncan,

I will re-post this on the suggested forumn. I didn't realise there was more than one.

P & P