Covered wooden bridges last hundreds of years and they are very beautiful. Maintenance is required (as with everything) but life cycle cost is really good especially for shorter spans.
GlueLam hasn't existed long enough for the glue-lamination aspect to be understood for climate, the way solid timbers are. I wanted to believe composites of all kinds had better lifecycle but it turns out Nature has some tricks up its sleeve which we don't yet entirely emulate, when it comes to longevity.
Down in Tasmania there are thousands of tonnes of flooded forest woods, which are being dredged up 50 or 60 years down in the cold dark dam-water, and being turned into exquisite furniture and musical instruments. I'm told almost petrified Kauri Pine can be the same, other woods turn into something magical when left alone for a long time. Put GluLam to the same test, It's probably not happy outcome.
Agree! The wet dry cycle at some point seems almost certain it would cause delamination. I'm surprised those failed bridges aren't more protected, it does seems risky, it seems they should be kept out of direct weather. Also agree glulams dont have a 100+ year track record, but it's getting there. They solve so many other issues such as efficient utilization of low grade and sustainable wood...so count me a cautious but excited proponent.
Good story about the Kauri Pine, that looks like a pretty cool tree!
Down in Tasmania there are thousands of tonnes of flooded forest woods, which are being dredged up 50 or 60 years down in the cold dark dam-water, and being turned into exquisite furniture and musical instruments. I'm told almost petrified Kauri Pine can be the same, other woods turn into something magical when left alone for a long time. Put GluLam to the same test, It's probably not happy outcome.