Timber prices in the Netherlands have more than doubled in recent months. It's also not clear when those prices will stabilize.   "Timber prices used to remain stable throughout the year. We could conclude contracts for longer periods. Nowadays, if I send out a quotation, you must accept it within a week or else the sales price has to be adjusted," says Robert Helder from Hoekman Houtindustrie.  “There's an issue with availability. That's for both sawn timber and board material. That includes chipboard, OSB, MDF, and hardboard. These are all frequently used ...