Is MDF suitable for exterior use, i.e. facia board?
Answers:
I have only seen this in south Spain but then again it doesn't rain down there very often , so don't feel to bad it was a good suggestion. But all the above answers are correct it will suck in water and fall apart.Try B & Q they have cheap plastic facia boards and you wont have to paint them they just nail over the existing facia board.
Other answers:
No, it swells when it gets wet.
No, it swells when it gets wet.
nope as soon as it gets wet it swells up and eventually falls to bits
I wouldn't - it is of similar consistency to weetabix (ie after soaking in milk) when wet.
you would be better using Marine quality plywood, or it might be called exterior plywood depending where you are from,
MDF is for interior use only
There is a waterproof version of MDF but it's hard to find and very expensive. Stick to marine ply, and make sure it's well painted/treated.
Absolutely not you should really only use hardwood but if you want to do a cheap job , well prepared wood,you can buy actual facia- board!
there is a product in the U.S. called MDB(multi density board).it come 3/4 in.,4x8 sheet.it has been used on cape cod(think saltwater) for years on exterior trim,such as trim for 1/2 round window.of course it is painted and i have never seen a problem with it.
there is also a composite 3/4 trim board that has been popping up alot on houses on the ocean lately.it is a PVC composite material that comes in differant widths and lenths,is paintable,and will never rot.it is very exspensive,though it should last a lifetime.i think you can get it in a 4/8 sheet also.might be something to look into.good luck.
No- Facia is perhaps 8 inches, after you cut MDF board that size, it will warp like hell between Rafter tails or look outs- Common practice is 2x6 as a backer for Vinyl or Aluminum Facia with same as soffit. If you want Wood, use No 2 Pine or Redwood. Do not use Plywood of any kind.
ends up like soggy weetabix