Moisture control

If there is one chapter to act on, it is this one. Moisture causes more expensive damage in manufactured homes than anything else, and it usually arrives slowly enough that nobody notices until the floor feels soft.

It has three sources. From below: ground moisture rising into an inadequately ventilated crawl space. From outside: roof and window leaks, and water pooling against the home because the ground slopes the wrong way. From inside: cooking, bathing, and drying clothes, in an envelope tighter than most houses.

The defences are unglamorous and they work. Keep skirting vents open and clear. Maintain a ground vapour barrier under the home if yours has one, and consider one if it does not. Slope the ground away on all sides, and direct downspouts away from the perimeter. Run bathroom and kitchen extraction and vent them outside, never into the crawl space or the roof void. Vent the clothes dryer to the exterior along the shortest run you can.

The warning signs are worth memorising: condensation on the inside of windows, a musty smell, peeling or bubbling flooring, soft or springy spots underfoot, dark staining on skirting or the belly wrap, and mould at the bottom of exterior walls or in cupboards on outside walls.

Act on those early. Moisture damage is progressive and it does not stop on its own, a soft spot in the floor today is a decking replacement in two years.