Insulation of roof in crawl space including dehumidifier

[Zippi]

I may need to remove the old roof in the crawl space and insulate new at the same time.

I will hire a construction company but wonder what is best to insulate with and what material should be used for the roof.

I will also install a dehumidifier, what brand do you suggest?

 

[Forskande Fukttekniker]

I might need to remove the old ceiling in the crawl space and insulate anew. I will hire a construction company but wonder what is best to insulate with and which material should be used for the ceiling. Also going to install a dehumidifier, what brand do you suggest?

A tip is not to insulate with cell plastic-styrofoam against the subfloor of the crawl space. Preferably use a moisture-permeable material so that an installed dehumidifier can also dehumidify the floor joists with its insulation. Oil-hardened board works well as long as it is kept dry and dehumidified. There are also stiffer insulation boards that allow moisture to pass through. There are several different sorption dehumidifiers today, which are most suitable for crawl spaces. Compare prices and make sure to buy from a party that can provide support. Many just sell without being able to offer any tips or advice. Also, lay construction plastic on the ground throughout the crawl space, so that the crawl space dehumidifier doesn't have to dehumidify the ground too, which is a constant and expensive project. If the moisture load is lower, not over 85% at any time during the year, a thermal dehumidifier can be good.