Had this now for about 2-3 weeks.

During the daytime no obvious smell but seems to "creep up" on you overnight so when you go in the garage next morning it hits you as you open the door.

We thought it was the drain as manhole cover in garage but having had a close look it looks fine and there is no smell.
We then thought it could be the fridge/freezer so we moved it out the garage but smell still appears.
Had a look in garage roof incase animal living up there or died up there but nothing and no smell - which is odd.

This then leaves me with either the boiler or possibly the air-con from my car?

I was wondering perhaps a smal split in my cars air-con pipe possibly?

Any useful suggestions/thoughts?

any dead ppl under your house?

Do you usually have dead animals in your garage roof space??


Now I've not been in a lab for several years now, but I know the odour of ammonia, but I can't imagine it at the moment. However if I smelt it I would immediately know it. Weird!!!

Is the garage part of the house or in a block?

Does it smell if you don't out the car in there?

Is someone running a speed lab next door?

Rotting fruit somewhere?

Got a tramp living/pising there?

Garage is next to the house and is connected to the house.

Always locked at night so no-one sneaking in.

No food stored in there apart from in fridge freezer

Leaving car in drive tonight to see how bad smell is tomorrow.

I believe an ant's nest can give off a smell of ammonia. Any sign?

Nope re ants.

My thought is the car being the problem as gets worse overnight - which is when car is normally garaged. Or some animal/bird nesting in the garage roof overnight and pissing in there.

Do you have any fertiliser or anything stored in there?

Not as far as I know re. fertiliser - again I would expect the smell to be present all the time - which it isn't.

Check the electrics.

I remember not long after we moved into our first house there was a strange chemical/ammonia smell coming from the understairs cupboard. I emptied the whole lot out and searched all over. Turns out the cable and circuit breaker for the electric shower wasn't rated for the shower installed but, instead of tripping out, it was slowly melting the fusebox!

Will update tomorrow.

If smell happens overnight then it rules out the air-con on the car and so we'll take a closer look at the electrics!

As I was reading the OP the thought running through my mind was... fox piss! We get that smell in the garden when the foxes have been around.

Is there a big pile of ammonia anywhere in your garage?