Our bedroom doors grow black mold on the outside of them , on the surface facing hallway.

Have bought and used specific cleaners to remove the mold but it quickly grows back , seems like a moisture issue.

The doors are wood that have been painted, asked if special anti mold resistant paints are available to prevent this and was told no.

Seems stock bedroom doors here are 200x80cm - would using door from a material other than wood prevent the mold from growing so quickly and easily ?

Try putting some liquid bleach (not the gel stuff) into a plastic spray bottle, spray and leave for 3 or 4 hours,and apply several times more.

It's difficult to clear completely,unless you spray with Bleach every week or two, it will come back due to the constant moisture and damp warmth in Bathrooms,an ideal breeding ground for Black mould.

I have used these two products to prevent mould on an outside wall and inside a storeroom. The first is to clean and kill the mould. The second is a primer to prevent the mould (and stain) showing through.

Not cheap, but very effective.

I suppose you could wash down with a bleach/water mixture and save a few Baht.

http://www.dulux.co.th/products/detail.jsp?id=39

http://www.dulux.co.th/products/detail.jsp?id=42

Edit to add - I first found the Dulux (ICI) products in Homepro. Next time I looked for them they were out of stock in Homepro, but I found them in Boonthavorn.

Let's try this in DIY

Yes, bleach usually works very well for mould, as said above. And use a strong bleach solution the the water when you clean the doors and around the house.

Some molds release toxins. Some of these can be very detrimental to health, and do not excrete from the body. Ever.

Wiping them exacerbates this. Bleach has no effect on the toxins.

I'd replace the doors, if that's all that's affected.

You said the doors are wood that have been painted... Probably not a good original job. Sand them down, re-prime, re-paint.

Some molds release toxins. Some of these can be very detrimental to health, and do not excrete from the body. Ever.

Wiping them exacerbates this. Bleach has no effect on the toxins.

I'd replace the doors, if that's all that's affected.

replacing the doors does not solve the OP's mold problem which can be a huge health hazard. he has to get the humidity down in his home. obviously he doesn't use airconditioning and there's hardly any natural light where the mold grows.

the problem might get better or disappear in a few weeks with the end of the rainy season. but the next rainy season will come for sure.

OP said bedroom/hall not bathroom so the obvious moisture source is not as evident. As said spraying bleach should help and the change of seasons should also. There are also paint formulations to retard such growth so suspect a misunderstanding when asking. Read some of the cans as believe it is marked. We have both wooden and plastic bathroom doors and no mold so it should be preventable once killed. Do recall many years ago did have such issues but newer paints seem to control well.