Hi my question is As follows.

I live in the uk and currently building my layout in my loft. My baseboard is constructed from softwood frame topped with MDF. However I left the layout for a couple of months to concentrate in the warm and when I returned my MDF was growing mould! Any ideas how to stop this?

Many thanks
Jim

As it does it on the MDF it will probably do it on other areas (ie buildings, scenery etc) when you model these.   I'ts almost certainly a condensation problem as lofts are notorious for their hot and cold extremes in Summer and Winter.   If you could create an insulated "room" within the loft - ie stud framing with Jablite slabs which are usually 2" thick and reasonably priced in B&Q etc. - it should stop this, a big project though!    (Or at least try insulating the inside roof area with Jablite above the layout and immediately adjacent to it which might work).    In other words the thing is to create a reasonably constant temperature which also has the advantage of a much nicer working environment.

Ken.

Thank you ken for your advice. I am about to insulate the inside of the roof area and walls in an attempt to keep the loft warm I winter and cool in summer. The loft is fully boarded. I am also thinking a oil filled heater on a thermostat

Jim

Once you've got you "room" Jim, a handy investment might be a dehumidifier.  They're not hugely expensive and they'll help keep the air dry but Ken's right, it's a condensation problem caused by temperature fluctuation.