New record high prices for lumber and wood panel products thanks to continuing robust demand from renovation and new home markets are driving stock prices higher for Canadian producers.  Five of the largest producers -- West Fraser Timber Co. Ltd., Interfor Corp., Canfor Corp., CanWel Building Materials Group Ltd. and Norbord Inc. -- all set new 52-week high at the end of August.  The strong prices are expected to continue for some time, said RBC Capital Markets analyst Paul Quinn in a report.  "We still see some upside to our 2021 estimates if ...