Too late for the OP, but here goes some advice anyway...
I had some issues with high rates of beer spoilage. The issue was what's sometimes referred to as "gusher bug" - an infection that eats up anything it can. The symptoms are an off flavour very early, kind of like clove, then as the beer ages, it becomes more medicinal, astringent, dry and way over carbonated. To the point that opening a bottle causes a fizzy geyser, like a Mentos in a Coke bottle. Like others, I battled this with various cleaning and sanitising regimes, but could not eliminate it. Even replaced all my equipment, to no positive results.
One day, on the spur of the moment, I decided I really didn't like the flooring in the kitchen and decided to rip up the old lino. What I found under that was some mould, a filthy old layer of another lino and under that a variety of floor coverings, ranging from asbestos sheets, chipboard, sandstone slab, hardwood floorboards and some kind of resin/bakelite impregnated woven material. What was going to be a quick job to replace some ugly lino turned out to be a major re-flooring of the kitchen. I pulled out everything I could, getting back to the floor boards and sandstone / concrete. Gave everything a good wash with sugar soap, then mopped it with a vinegar. Once dry, I sprayed with metho and then mopped with bleach. Then it was a couple of days of drying. During that time I noticed that the sandstone and concrete parts of the floor were wicking up the moisture from under the house and it became clear that this was always going to be a damp and mould problem, because moisture would be drawn from under the house and then trapped under the floor coverings. Since the floor was also uneven in that area, I got a few bags of floor leveler, mixed it up and poured it over the affected area. Once the leveler set and dried, I got some bathroom waterproofing membrane and painted two coats over the sandstone, the concrete, the leveler and a good 30-50cm of surrounding floorboards. For the rest of the floor, I used a PVA (as in PVA glue) floor sealer that you just paint on the floorboards. I then covered the treated floor with self-adhesive lino rectangles that are each manufactured to resemble a floor board. I also installed some extra vent bricks around the perimeter of the house and an electric fan with some ducting and a timer that runs for an hour in the morning and an hour in the afternoon, just to ventilate under the house and get any moisture out of there.
About two or three months after this, I cleaned all my existing equipment (the same gear I had issues with in the past) and decided to brew again. This time the results were just fine, no infection, no off flavours, spot on carbonation and beer that lasted for good 6 months without any "gusher bug" issues. No idea if it would have lasted any longer, it was too yum to resist ;-)
So, yes, the environment can be a big, big factor and fixing the problem can be a major job. It's usually the stuff you don't see. The floor is clean on the surface, but what's under it? The walls and ceilings are clean, but what's inside the cavities? Sometimes you just need to peel back the layers and inspect.
