This may be a new use for the 5T blade. My 20 year old pressure treated deck is still in great shape, except for the lack of gaps between the boards.
Board swelling, and warping over time eliminated 80% of the gaps, dirt, and other "stuff" filled the remaining 20% of the gaps.When it rained, the deck became a "duck pond", holding water, sometimes for days.
The deck surface is 2X6, rather than the typical 5/4x6, and the 2X6's were installed with the typical "nail width" gap. Well, after many attempts to clean the gaps, I decided to "saw" the gaps to widen them, A regular blade would not cut the treated wood, the blade would clog with the large amount of sawdust being created. A regular blade was too narrow, I even tried stacking three blades on the saw at one time. Slivers would jam in between the blades, making them wobble.
Well, I found the 5T blade, and today I widened the gap on over 400 linear feet of gap, I have that much or more to do tomorrow.
Due to the 2X6's swelling, the gap ranged from zero to no more than 1/8", now I have a uniform 3/16" gap between the deck boards that I cut. We found a coating that will make the deck look great, but, the coating would not have worked with the dirt, and rocks filling the gaps between the boards. I know there were some rocks (small), because I saw the sparks fly when I hit them.
The 5T has SAVED our deck, maybe it is not only for demo, anymore!!??