How Do You Make Indoor/Outdoor Glulam Arches?
When your glulam is going to be installed outdoors, treated lumber should be your first choice to ensure longevity in the wood. But, treatment does add expense, and sometimes only part of your column, beam, or arch is going to be exposed outside. In that case, it makes sense to treat the exterior part of the glulam and feather in untreated material where it will not be subject to the elements.
This is an example of one partially treated arch that we recently made in our plant, and there were 15 other half arches just like this on the full job. The green colored wood is treated, the rest is not. You may notice that the finger joints in the individual glulam plies are staggered. This takes careful work by our team and is done for structural reasons. Although stacked joints are technically allowed in most cases, it is always better to stagger all joints, so that’s what we do.
